From 6e7b96ca3a7d47b0441bed904a9b8bb25c3223de Mon Sep 17 00:00:00 2001 From: jaybinks Date: Wed, 12 Sep 2007 12:43:38 +0000 Subject: * added missed dependency PNGImage. * moved FUNCTION InitializePaths(), from uFiles to uMain as this is a more sane location for it. * updated files that used UFiles to point to UMain, and removed uFiles where its not needed. git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@385 b956fd51-792f-4845-bead-9b4dfca2ff2c --- Game/Code/lib/PngImage/pngimage.~pas | 5205 ++++++++++++++++++++++++++++++++++ 1 file changed, 5205 insertions(+) create mode 100644 Game/Code/lib/PngImage/pngimage.~pas (limited to 'Game/Code/lib/PngImage/pngimage.~pas') diff --git a/Game/Code/lib/PngImage/pngimage.~pas b/Game/Code/lib/PngImage/pngimage.~pas new file mode 100644 index 00000000..ec712737 --- /dev/null +++ b/Game/Code/lib/PngImage/pngimage.~pas @@ -0,0 +1,5205 @@ +{Portable Network Graphics Delphi 1.4361 (8 March 2003) } + +{This is the latest implementation for TPngImage component } +{It's meant to be a full replacement for the previous one. } +{There are lots of new improvements, including cleaner code, } +{full partial transparency support, speed improvements, } +{saving using ADAM 7 interlacing, better error handling, also } +{the best compression for the final image ever. And now it's } +{truly able to read about any png image. } + +{ + Version 1.4361 + 2003-03-04 - Fixed important bug for simple transparency when using + RGB, Grayscale color modes + + Version 1.436 + 2003-03-04 - * NEW * Property Pixels for direct access to pixels + * IMPROVED * Palette property (TPngObject) (read only) + Slovenian traslation for the component (Miha Petelin) + Help file update (scanline article/png->jpg example) + + Version 1.435 + 2003-11-03 - * NEW * New chunk implementation zTXt (method AddzTXt) + * NEW * New compiler flags to store the extra 8 bits + from 16 bits samples (when saving it is ignored), the + extra data may be acessed using ExtraScanline property + * Fixed * a bug on tIMe chunk + French translation included (Thanks to IBE Software) + Bugs fixed + + Version 1.432 + 2002-08-24 - * NEW * A new method, CreateAlpha will transform the + current image into partial transparency. + Help file updated with a new article on how to handle + partial transparency. + + Version 1.431 + 2002-08-14 - Fixed and tested to work on: + C++ Builder 3 + C++ Builder 5 + Delphi 3 + There was an error when setting TransparentColor, fixed + New method, RemoveTransparency to remove image + BIT TRANSPARENCY + + Version 1.43 + 2002-08-01 - * NEW * Support for Delphi 3 and C++ Builder 3 + Implements mostly some things that were missing, + a few tweaks and fixes. + + Version 1.428 + 2002-07-24 - More minor fixes (thanks to Ian Boyd) + Bit transparency fixes + * NEW * Finally support to bit transparency + (palette / rgb / grayscale -> all) + + Version 1.427 + 2002-07-19 - Lots of bugs and leaks fixed + * NEW * method to easy adding text comments, AddtEXt + * NEW * property for setting bit transparency, + TransparentColor + + Version 1.426 + 2002-07-18 - Clipboard finally fixed (hope) + Changed UseDelphi trigger to UseDelphi + * NEW * Support for bit transparency bitmaps + when assigning from/to TBitmap objects + Altough it does not support drawing transparent + parts of bit transparency pngs (only partial) + it is closer than ever + + Version 1.425 + 2002-07-01 - Clipboard methods implemented + Lots of bugs fixed + + Version 1.424 + 2002-05-16 - Scanline and AlphaScanline are now working correctly. + New methods for handling the clipboard + + Version 1.423 + 2002-05-16 - * NEW * Partial transparency for 1, 2, 4 and 8 bits is + also supported using the tRNS chunk (for palette and + grayscaling). + New bug fixes (Peter Haas). + + Version 1.422 + 2002-05-14 - Fixed some critical leaks, thanks to Peter Haas tips. + New translation for German (Peter Haas). + + Version 1.421 + 2002-05-06 - Now uses new ZLIB version, 1.1.4 with some security + fixes. + LoadFromResourceID and LoadFromResourceName added and + help file updated for that. + The resources strings are now located in pnglang.pas. + New translation for Brazilian Portuguese. + Bugs fixed. + + IMPORTANT: I'm currently looking for bugs on the library. If + anyone has found one, please send me an email and + I will fix right away. Thanks for all the help and + ideias I'm receiving so far.} + +{My new email is: gubadaud@terra.com.br} +{Website link : pngdelphi.sourceforge.net} +{Gustavo Huffenbacher Daud} + +unit pngimage; + +interface + +{Triggers avaliable (edit the fields bellow)} +{$DEFINE UseDelphi} //Disable fat vcl units (perfect to small apps) +{$DEFINE ErrorOnUnknownCritical} //Error when finds an unknown critical chunk +{$DEFINE CheckCRC} //Enables CRC checking +{$DEFINE RegisterGraphic} //Registers TPNGObject to use with TPicture +{$DEFINE PartialTransparentDraw} //Draws partial transparent images +{.$DEFINE Store16bits} //Stores the extra 8 bits from 16bits/sample +{.$DEFINE Debug} //For programming purposes +{$RANGECHECKS OFF} {$J+} + + + +uses + Windows {$IFDEF UseDelphi}, Classes, Graphics, SysUtils{$ENDIF} {$IFDEF Debug}, + dialogs{$ENDIF}, pngzlib, pnglang; + +{$IFNDEF UseDelphi} + const + soFromBeginning = 0; + soFromCurrent = 1; + soFromEnd = 2; +{$ENDIF} + +const + {ZLIB constants} + ZLIBErrors: Array[-6..2] of string = ('incompatible version (-6)', + 'buffer error (-5)', 'insufficient memory (-4)', 'data error (-3)', + 'stream error (-2)', 'file error (-1)', '(0)', 'stream end (1)', + 'need dictionary (2)'); + Z_NO_FLUSH = 0; + Z_FINISH = 4; + Z_STREAM_END = 1; + + {Avaliable PNG filters for mode 0} + FILTER_NONE = 0; + FILTER_SUB = 1; + FILTER_UP = 2; + FILTER_AVERAGE = 3; + FILTER_PAETH = 4; + + {Avaliable color modes for PNG} + COLOR_GRAYSCALE = 0; + COLOR_RGB = 2; + COLOR_PALETTE = 3; + COLOR_GRAYSCALEALPHA = 4; + COLOR_RGBALPHA = 6; + + +type + {$IFNDEF UseDelphi} + {Custom exception handler} + Exception = class(TObject) + constructor Create(Msg: String); + end; + ExceptClass = class of Exception; + TColor = ColorRef; + {$ENDIF} + + {Error types} + EPNGOutMemory = class(Exception); + EPngError = class(Exception); + EPngUnexpectedEnd = class(Exception); + EPngInvalidCRC = class(Exception); + EPngInvalidIHDR = class(Exception); + EPNGMissingMultipleIDAT = class(Exception); + EPNGZLIBError = class(Exception); + EPNGInvalidPalette = class(Exception); + EPNGInvalidFileHeader = class(Exception); + EPNGIHDRNotFirst = class(Exception); + EPNGNotExists = class(Exception); + EPNGSizeExceeds = class(Exception); + EPNGMissingPalette = class(Exception); + EPNGUnknownCriticalChunk = class(Exception); + EPNGUnknownCompression = class(Exception); + EPNGUnknownInterlace = class(Exception); + EPNGNoImageData = class(Exception); + EPNGCouldNotLoadResource = class(Exception); + EPNGCannotChangeTransparent = class(Exception); + EPNGHeaderNotPresent = class(Exception); + +type + {Direct access to pixels using R,G,B} + TRGBLine = array[word] of TRGBTriple; + pRGBLine = ^TRGBLine; + + {Same as TBitmapInfo but with allocated space for} + {palette entries} + TMAXBITMAPINFO = packed record + bmiHeader: TBitmapInfoHeader; + bmiColors: packed array[0..255] of TRGBQuad; + end; + + {Transparency mode for pngs} + TPNGTransparencyMode = (ptmNone, ptmBit, ptmPartial); + {Pointer to a cardinal type} + pCardinal = ^Cardinal; + {Access to a rgb pixel} + pRGBPixel = ^TRGBPixel; + TRGBPixel = packed record + B, G, R: Byte; + end; + + {Pointer to an array of bytes type} + TByteArray = Array[Word] of Byte; + pByteArray = ^TByteArray; + + {Forward} + TPNGObject = class; + pPointerArray = ^TPointerArray; + TPointerArray = Array[Word] of Pointer; + + {Contains a list of objects} + TPNGPointerList = class + private + fOwner: TPNGObject; + fCount : Cardinal; + fMemory: pPointerArray; + function GetItem(Index: Cardinal): Pointer; + procedure SetItem(Index: Cardinal; const Value: Pointer); + protected + {Removes an item} + function Remove(Value: Pointer): Pointer; virtual; + {Inserts an item} + procedure Insert(Value: Pointer; Position: Cardinal); + {Add a new item} + procedure Add(Value: Pointer); + {Returns an item} + property Item[Index: Cardinal]: Pointer read GetItem write SetItem; + {Set the size of the list} + procedure SetSize(const Size: Cardinal); + {Returns owner} + property Owner: TPNGObject read fOwner; + public + {Returns number of items} + property Count: Cardinal read fCount write SetSize; + {Object being either created or destroyed} + constructor Create(AOwner: TPNGObject); + destructor Destroy; override; + end; + + {Forward declaration} + TChunk = class; + TChunkClass = class of TChunk; + + {Same as TPNGPointerList but providing typecasted values} + TPNGList = class(TPNGPointerList) + private + {Used with property Item} + function GetItem(Index: Cardinal): TChunk; + public + {Removes an item} + procedure RemoveChunk(Chunk: TChunk); overload; + {Add a new chunk using the class from the parameter} + function Add(ChunkClass: TChunkClass): TChunk; + {Returns pointer to the first chunk of class} + function ItemFromClass(ChunkClass: TChunkClass): TChunk; + {Returns a chunk item from the list} + property Item[Index: Cardinal]: TChunk read GetItem; + end; + + {$IFNDEF UseDelphi} + {The STREAMs bellow are only needed in case delphi provided ones is not} + {avaliable (UseDelphi trigger not set)} + {Object becomes handles} + TCanvas = THandle; + TBitmap = HBitmap; + {Trick to work} + TPersistent = TObject; + + {Base class for all streams} + TStream = class + protected + {Returning/setting size} + function GetSize: Longint; virtual; + procedure SetSize(const Value: Longint); virtual; abstract; + {Returns/set position} + function GetPosition: Longint; virtual; + procedure SetPosition(const Value: Longint); virtual; + public + {Returns/sets current position} + property Position: Longint read GetPosition write SetPosition; + {Property returns/sets size} + property Size: Longint read GetSize write SetSize; + {Allows reading/writing data} + function Read(var Buffer; Count: Longint): Cardinal; virtual; abstract; + function Write(const Buffer; Count: Longint): Cardinal; virtual; abstract; + {Copies from another Stream} + function CopyFrom(Source: TStream; + Count: Cardinal): Cardinal; virtual; + {Seeks a stream position} + function Seek(Offset: Longint; Origin: Word): Longint; virtual; abstract; + end; + + {File stream modes} + TFileStreamMode = (fsmRead, fsmWrite, fsmCreate); + TFileStreamModeSet = set of TFileStreamMode; + + {File stream for reading from files} + TFileStream = class(TStream) + private + {Opened mode} + Filemode: TFileStreamModeSet; + {Handle} + fHandle: THandle; + protected + {Set the size of the file} + procedure SetSize(const Value: Longint); override; + public + {Seeks a file position} + function Seek(Offset: Longint; Origin: Word): Longint; override; + {Reads/writes data from/to the file} + function Read(var Buffer; Count: Longint): Cardinal; override; + function Write(const Buffer; Count: Longint): Cardinal; override; + {Stream being created and destroy} + constructor Create(Filename: String; Mode: TFileStreamModeSet); + destructor Destroy; override; + end; + + {Stream for reading from resources} + TResourceStream = class(TStream) + constructor Create(Instance: HInst; const ResName: String; ResType:PChar); + private + {Variables for reading} + Size: Integer; + Memory: Pointer; + Position: Integer; + protected + {Set the size of the file} + procedure SetSize(const Value: Longint); override; + public + {Stream processing} + function Read(var Buffer; Count: Integer): Cardinal; override; + function Seek(Offset: Integer; Origin: Word): Longint; override; + function Write(const Buffer; Count: Longint): Cardinal; override; + end; + {$ENDIF} + + {Forward} + TChunkIHDR = class; + {Interlace method} + TInterlaceMethod = (imNone, imAdam7); + {Compression level type} + TCompressionLevel = 0..9; + {Filters type} + TFilter = (pfNone, pfSub, pfUp, pfAverage, pfPaeth); + TFilters = set of TFilter; + + {Png implementation object} + TPngObject = class{$IFDEF UseDelphi}(TGraphic){$ENDIF} + protected + {Gamma table values} + GammaTable, InverseGamma: Array[Byte] of Byte; + procedure InitializeGamma; + private + {Temporary palette} + TempPalette: HPalette; + {Filters to test to encode} + fFilters: TFilters; + {Compression level for ZLIB} + fCompressionLevel: TCompressionLevel; + {Maximum size for IDAT chunks} + fMaxIdatSize: Cardinal; + {Returns if image is interlaced} + fInterlaceMethod: TInterlaceMethod; + {Chunks object} + fChunkList: TPngList; + {Clear all chunks in the list} + procedure ClearChunks; + {Returns if header is present} + function HeaderPresent: Boolean; + {Returns linesize and byte offset for pixels} + procedure GetPixelInfo(var LineSize, Offset: Cardinal); + procedure SetMaxIdatSize(const Value: Cardinal); + function GetAlphaScanline(const LineIndex: Integer): pByteArray; + function GetScanline(const LineIndex: Integer): Pointer; + {$IFDEF Store16bits} + function GetExtraScanline(const LineIndex: Integer): Pointer; + {$ENDIF} + function GetTransparencyMode: TPNGTransparencyMode; + function GetTransparentColor: TColor; + procedure SetTransparentColor(const Value: TColor); + protected + {Returns the image palette} + function GetPalette: HPALETTE; {$IFDEF UseDelphi}override;{$ENDIF} + {Returns/sets image width and height} + function GetWidth: Integer; {$IFDEF UseDelphi}override;{$ENDIF} + function GetHeight: Integer; {$IFDEF UseDelphi}override; {$ENDIF} + procedure SetWidth(Value: Integer); {$IFDEF UseDelphi}override; {$ENDIF} + procedure SetHeight(Value: Integer); {$IFDEF UseDelphi}override;{$ENDIF} + {Assigns from another TPNGObject} + procedure AssignPNG(Source: TPNGObject); + {Returns if the image is empty} + function GetEmpty: Boolean; {$IFDEF UseDelphi}override; {$ENDIF} + {Used with property Header} + function GetHeader: TChunkIHDR; + {Draws using partial transparency} + procedure DrawPartialTrans(DC: HDC; Rect: TRect); + {$IFDEF UseDelphi} + {Returns if the image is transparent} + function GetTransparent: Boolean; override; + {$ENDIF} + {Returns a pixel} + function GetPixels(const X, Y: Integer): TColor; virtual; + procedure SetPixels(const X, Y: Integer; const Value: TColor); virtual; + public + {Generates alpha information} + procedure CreateAlpha; + {Removes the image transparency} + procedure RemoveTransparency; + {Transparent color} + property TransparentColor: TColor read GetTransparentColor write + SetTransparentColor; + {Add text chunk, TChunkTEXT, TChunkzTXT} + procedure AddtEXt(const Keyword, Text: String); + procedure AddzTXt(const Keyword, Text: String); + {$IFDEF UseDelphi} + {Saves to clipboard format (thanks to Antoine Pottern)} + procedure SaveToClipboardFormat(var AFormat: Word; var AData: THandle; + var APalette: HPalette); override; + procedure LoadFromClipboardFormat(AFormat: Word; AData: THandle; + APalette: HPalette); override; + {$ENDIF} + {Calling errors} + procedure RaiseError(ExceptionClass: ExceptClass; Text: String); + {Returns a scanline from png} + property Scanline[const Index: Integer]: Pointer read GetScanline; + {$IFDEF Store16bits} + property ExtraScanline[const Index: Integer]: Pointer read GetExtraScanline; + {$ENDIF} + property AlphaScanline[const Index: Integer]: pByteArray read GetAlphaScanline; + {Returns pointer to the header} + property Header: TChunkIHDR read GetHeader; + {Returns the transparency mode used by this png} + property TransparencyMode: TPNGTransparencyMode read GetTransparencyMode; + {Assigns from another object} + procedure Assign(Source: TPersistent);{$IFDEF UseDelphi}override;{$ENDIF} + {Assigns to another object} + procedure AssignTo(Dest: TPersistent);{$IFDEF UseDelphi}override;{$ENDIF} + {Assigns from a windows bitmap handle} + procedure AssignHandle(Handle: HBitmap; Transparent: Boolean; + TransparentColor: ColorRef); + {Draws the image into a canvas} + procedure Draw(ACanvas: TCanvas; const Rect: TRect); + {$IFDEF UseDelphi}override;{$ENDIF} + {Width and height properties} + property Width: Integer read GetWidth; + property Height: Integer read GetHeight; + {Returns if the image is interlaced} + property InterlaceMethod: TInterlaceMethod read fInterlaceMethod + write fInterlaceMethod; + {Filters to test to encode} + property Filters: TFilters read fFilters write fFilters; + {Maximum size for IDAT chunks, default and minimum is 65536} + property MaxIdatSize: Cardinal read fMaxIdatSize write SetMaxIdatSize; + {Property to return if the image is empty or not} + property Empty: Boolean read GetEmpty; + {Compression level} + property CompressionLevel: TCompressionLevel read fCompressionLevel + write fCompressionLevel; + {Access to the chunk list} + property Chunks: TPngList read fChunkList; + {Object being created and destroyed} + constructor Create; {$IFDEF UseDelphi}override;{$ENDIF} + destructor Destroy; override; + {$IFNDEF UseDelphi}procedure LoadFromFile(const Filename: String);{$ENDIF} + {$IFNDEF UseDelphi}procedure SaveToFile(const Filename: String);{$ENDIF} + procedure LoadFromStream(Stream: TStream); {$IFDEF UseDelphi}override;{$ENDIF} + procedure SaveToStream(Stream: TStream); {$IFDEF UseDelphi}override;{$ENDIF} + {Loading the image from resources} + procedure LoadFromResourceName(Instance: HInst; const Name: String); + procedure LoadFromResourceID(Instance: HInst; ResID: Integer); + {Access to the png pixels} + property Pixels[const X, Y: Integer]: TColor read GetPixels write SetPixels; + {Palette property} + {$IFNDEF UseDelphi}property Palette: HPalette read GetPalette;{$ENDIF} + end; + + {Chunk name object} + TChunkName = Array[0..3] of Char; + + {Global chunk object} + TChunk = class + private + {Contains data} + fData: Pointer; + fDataSize: Cardinal; + {Stores owner} + fOwner: TPngObject; + {Stores the chunk name} + fName: TChunkName; + {Returns pointer to the TChunkIHDR} + function GetHeader: TChunkIHDR; + {Used with property index} + function GetIndex: Integer; + {Should return chunk class/name} + class function GetName: String; virtual; + {Returns the chunk name} + function GetChunkName: String; + public + {Returns index from list} + property Index: Integer read GetIndex; + {Returns pointer to the TChunkIHDR} + property Header: TChunkIHDR read GetHeader; + {Resize the data} + procedure ResizeData(const NewSize: Cardinal); + {Returns data and size} + property Data: Pointer read fData; + property DataSize: Cardinal read fDataSize; + {Assigns from another TChunk} + procedure Assign(Source: TChunk); virtual; + {Returns owner} + property Owner: TPngObject read fOwner; + {Being destroyed/created} + constructor Create(Owner: TPngObject); virtual; + destructor Destroy; override; + {Returns chunk class/name} + property Name: String read GetChunkName; + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; virtual; + {Saves the chunk to a stream} + function SaveData(Stream: TStream): Boolean; + function SaveToStream(Stream: TStream): Boolean; virtual; + end; + + {Chunk classes} + TChunkIEND = class(TChunk); {End chunk} + + {IHDR data} + pIHDRData = ^TIHDRData; + TIHDRData = packed record + Width, Height: Cardinal; + BitDepth, + ColorType, + CompressionMethod, + FilterMethod, + InterlaceMethod: Byte; + end; + + {Information header chunk} + TChunkIHDR = class(TChunk) + private + {Current image} + ImageHandle: HBitmap; + ImageDC: HDC; + + {Output windows bitmap} + HasPalette: Boolean; + BitmapInfo: TMaxBitmapInfo; + BytesPerRow: Integer; + {Stores the image bytes} + {$IFDEF Store16bits}ExtraImageData: Pointer;{$ENDIF} + ImageData: pointer; + ImageAlpha: Pointer; + + {Contains all the ihdr data} + IHDRData: TIHDRData; + protected + {Resizes the image data to fill the color type, bit depth, } + {width and height parameters} + procedure PrepareImageData; + {Release allocated ImageData memory} + procedure FreeImageData; + public + {Properties} + property Width: Cardinal read IHDRData.Width write IHDRData.Width; + property Height: Cardinal read IHDRData.Height write IHDRData.Height; + property BitDepth: Byte read IHDRData.BitDepth write IHDRData.BitDepth; + property ColorType: Byte read IHDRData.ColorType write IHDRData.ColorType; + property CompressionMethod: Byte read IHDRData.CompressionMethod + write IHDRData.CompressionMethod; + property FilterMethod: Byte read IHDRData.FilterMethod + write IHDRData.FilterMethod; + property InterlaceMethod: Byte read IHDRData.InterlaceMethod + write IHDRData.InterlaceMethod; + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Saves the chunk to a stream} + function SaveToStream(Stream: TStream): Boolean; override; + {Destructor/constructor} + constructor Create(Owner: TPngObject); override; + destructor Destroy; override; + {Assigns from another TChunk} + procedure Assign(Source: TChunk); override; + end; + + {Gamma chunk} + TChunkgAMA = class(TChunk) + private + {Returns/sets the value for the gamma chunk} + function GetValue: Cardinal; + procedure SetValue(const Value: Cardinal); + public + {Returns/sets gamma value} + property Gamma: Cardinal read GetValue write SetValue; + {Loading the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Being created} + constructor Create(Owner: TPngObject); override; + {Assigns from another TChunk} + procedure Assign(Source: TChunk); override; + end; + + {ZLIB Decompression extra information} + TZStreamRec2 = packed record + {From ZLIB} + ZLIB: TZStreamRec; + {Additional info} + Data: Pointer; + fStream : TStream; + end; + + {Palette chunk} + TChunkPLTE = class(TChunk) + private + {Number of items in the palette} + fCount: Integer; + {Contains the palette handle} + function GetPaletteItem(Index: Byte): TRGBQuad; + public + {Returns the color for each item in the palette} + property Item[Index: Byte]: TRGBQuad read GetPaletteItem; + {Returns the number of items in the palette} + property Count: Integer read fCount; + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Saves the chunk to a stream} + function SaveToStream(Stream: TStream): Boolean; override; + {Assigns from another TChunk} + procedure Assign(Source: TChunk); override; + end; + + {Transparency information} + TChunktRNS = class(TChunk) + private + fBitTransparency: Boolean; + function GetTransparentColor: ColorRef; + {Returns the transparent color} + procedure SetTransparentColor(const Value: ColorRef); + public + {Palette values for transparency} + PaletteValues: Array[Byte] of Byte; + {Returns if it uses bit transparency} + property BitTransparency: Boolean read fBitTransparency; + {Returns the transparent color} + property TransparentColor: ColorRef read GetTransparentColor write + SetTransparentColor; + {Loads/saves the chunk from/to a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + function SaveToStream(Stream: TStream): Boolean; override; + {Assigns from another TChunk} + procedure Assign(Source: TChunk); override; + end; + + {Actual image information} + TChunkIDAT = class(TChunk) + private + {Holds another pointer to the TChunkIHDR} + Header: TChunkIHDR; + {Stores temporary image width and height} + ImageWidth, ImageHeight: Integer; + {Size in bytes of each line and offset} + Row_Bytes, Offset : Cardinal; + {Contains data for the lines} + Encode_Buffer: Array[0..5] of pByteArray; + Row_Buffer: Array[Boolean] of pByteArray; + {Variable to invert the Row_Buffer used} + RowUsed: Boolean; + {Ending position for the current IDAT chunk} + EndPos: Integer; + {Filter the current line} + procedure FilterRow; + {Filter to encode and returns the best filter} + function FilterToEncode: Byte; + {Reads ZLIB compressed data} + function IDATZlibRead(var ZLIBStream: TZStreamRec2; Buffer: Pointer; + Count: Integer; var EndPos: Integer; var crcfile: Cardinal): Integer; + {Compress and writes IDAT data} + procedure IDATZlibWrite(var ZLIBStream: TZStreamRec2; Buffer: Pointer; + const Length: Cardinal); + procedure FinishIDATZlib(var ZLIBStream: TZStreamRec2); + {Prepares the palette} + procedure PreparePalette; + protected + {Decode interlaced image} + procedure DecodeInterlacedAdam7(Stream: TStream; + var ZLIBStream: TZStreamRec2; const Size: Integer; var crcfile: Cardinal); + {Decode non interlaced imaged} + procedure DecodeNonInterlaced(Stream: TStream; + var ZLIBStream: TZStreamRec2; const Size: Integer; + var crcfile: Cardinal); + protected + {Encode non interlaced images} + procedure EncodeNonInterlaced(Stream: TStream; + var ZLIBStream: TZStreamRec2); + {Encode interlaced images} + procedure EncodeInterlacedAdam7(Stream: TStream; + var ZLIBStream: TZStreamRec2); + protected + {Memory copy methods to decode} + procedure CopyNonInterlacedRGB8( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedRGB16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedPalette148( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedPalette2( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedGray2( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedGrayscale16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedRGBAlpha8( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedRGBAlpha16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedGrayscaleAlpha8( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyNonInterlacedGrayscaleAlpha16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedRGB8(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedRGB16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedPalette148(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedPalette2(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedGray2(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedGrayscale16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedRGBAlpha8(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedRGBAlpha16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedGrayscaleAlpha8(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + procedure CopyInterlacedGrayscaleAlpha16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); + protected + {Memory copy methods to encode} + procedure EncodeNonInterlacedRGB8(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedRGB16(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedGrayscale16(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedPalette148(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedRGBAlpha8(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedRGBAlpha16(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedGrayscaleAlpha8(Src, Dest, Trans: pChar); + procedure EncodeNonInterlacedGrayscaleAlpha16(Src, Dest, Trans: pChar); + procedure EncodeInterlacedRGB8(const Pass: Byte; Src, Dest, Trans: pChar); + procedure EncodeInterlacedRGB16(const Pass: Byte; Src, Dest, Trans: pChar); + procedure EncodeInterlacedPalette148(const Pass: Byte; + Src, Dest, Trans: pChar); + procedure EncodeInterlacedGrayscale16(const Pass: Byte; + Src, Dest, Trans: pChar); + procedure EncodeInterlacedRGBAlpha8(const Pass: Byte; + Src, Dest, Trans: pChar); + procedure EncodeInterlacedRGBAlpha16(const Pass: Byte; + Src, Dest, Trans: pChar); + procedure EncodeInterlacedGrayscaleAlpha8(const Pass: Byte; + Src, Dest, Trans: pChar); + procedure EncodeInterlacedGrayscaleAlpha16(const Pass: Byte; + Src, Dest, Trans: pChar); + public + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Saves the chunk to a stream} + function SaveToStream(Stream: TStream): Boolean; override; + end; + + {Image last modification chunk} + TChunktIME = class(TChunk) + private + {Holds the variables} + fYear: Word; + fMonth, fDay, fHour, fMinute, fSecond: Byte; + public + {Returns/sets variables} + property Year: Word read fYear write fYear; + property Month: Byte read fMonth write fMonth; + property Day: Byte read fDay write fDay; + property Hour: Byte read fHour write fHour; + property Minute: Byte read fMinute write fMinute; + property Second: Byte read fSecond write fSecond; + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Saves the chunk to a stream} + function SaveToStream(Stream: TStream): Boolean; override; + end; + + {Textual data} + TChunktEXt = class(TChunk) + private + fKeyword, fText: String; + public + {Keyword and text} + property Keyword: String read fKeyword write fKeyword; + property Text: String read fText write fText; + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Saves the chunk to a stream} + function SaveToStream(Stream: TStream): Boolean; override; + {Assigns from another TChunk} + procedure Assign(Source: TChunk); override; + end; + + {zTXT chunk} + TChunkzTXt = class(TChunktEXt) + {Loads the chunk from a stream} + function LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; override; + {Saves the chunk to a stream} + function SaveToStream(Stream: TStream): Boolean; override; + end; + +{Here we test if it's c++ builder or delphi version 3 or less} +{$IFDEF VER110}{$DEFINE DelphiBuilder3Less}{$ENDIF} +{$IFDEF VER100}{$DEFINE DelphiBuilder3Less}{$ENDIF} +{$IFDEF VER93}{$DEFINE DelphiBuilder3Less}{$ENDIF} +{$IFDEF VER90}{$DEFINE DelphiBuilder3Less}{$ENDIF} +{$IFDEF VER80}{$DEFINE DelphiBuilder3Less}{$ENDIF} + + +{Registers a new chunk class} +procedure RegisterChunk(ChunkClass: TChunkClass); +{Calculates crc} +function update_crc(crc: {$IFNDEF DelphiBuilder3Less}Cardinal{$ELSE}Integer + {$ENDIF}; buf: pByteArray; len: Integer): Cardinal; +{Invert bytes using assembly} +function ByteSwap(const a: integer): integer; + +implementation + +var + ChunkClasses: TPngPointerList; + {Table of CRCs of all 8-bit messages} + crc_table: Array[0..255] of Cardinal; + {Flag: has the table been computed? Initially false} + crc_table_computed: Boolean; + +{Draw transparent image using transparent color} +procedure DrawTransparentBitmap(dc: HDC; srcBits: Pointer; + var srcHeader: TBitmapInfoHeader; + srcBitmapInfo: pBitmapInfo; Rect: TRect; cTransparentColor: COLORREF); +var + cColor: COLORREF; + bmAndBack, bmAndObject, bmAndMem: HBITMAP; + bmBackOld, bmObjectOld, bmMemOld: HBITMAP; + hdcMem, hdcBack, hdcObject, hdcTemp: HDC; + ptSize, orgSize: TPOINT; + OldBitmap, DrawBitmap: HBITMAP; +begin + hdcTemp := CreateCompatibleDC(dc); + // Select the bitmap + DrawBitmap := CreateDIBitmap(dc, srcHeader, CBM_INIT, srcBits, srcBitmapInfo^, + DIB_RGB_COLORS); + OldBitmap := SelectObject(hdcTemp, DrawBitmap); + + // Sizes + OrgSize.x := abs(srcHeader.biWidth); + OrgSize.y := abs(srcHeader.biHeight); + ptSize.x := Rect.Right - Rect.Left; // Get width of bitmap + ptSize.y := Rect.Bottom - Rect.Top; // Get height of bitmap + + // Create some DCs to hold temporary data. + hdcBack := CreateCompatibleDC(dc); + hdcObject := CreateCompatibleDC(dc); + hdcMem := CreateCompatibleDC(dc); + + // Create a bitmap for each DC. DCs are required for a number of + // GDI functions. + + // Monochrome DCs + bmAndBack := CreateBitmap(ptSize.x, ptSize.y, 1, 1, nil); + bmAndObject := CreateBitmap(ptSize.x, ptSize.y, 1, 1, nil); + + bmAndMem := CreateCompatibleBitmap(dc, ptSize.x, ptSize.y); + + // Each DC must select a bitmap object to store pixel data. + bmBackOld := SelectObject(hdcBack, bmAndBack); + bmObjectOld := SelectObject(hdcObject, bmAndObject); + bmMemOld := SelectObject(hdcMem, bmAndMem); + + // Set the background color of the source DC to the color. + // contained in the parts of the bitmap that should be transparent + cColor := SetBkColor(hdcTemp, cTransparentColor); + + // Create the object mask for the bitmap by performing a BitBlt + // from the source bitmap to a monochrome bitmap. + StretchBlt(hdcObject, 0, 0, ptSize.x, ptSize.y, hdcTemp, 0, 0, + orgSize.x, orgSize.y, SRCCOPY); + + // Set the background color of the source DC back to the original + // color. + SetBkColor(hdcTemp, cColor); + + // Create the inverse of the object mask. + BitBlt(hdcBack, 0, 0, ptSize.x, ptSize.y, hdcObject, 0, 0, + NOTSRCCOPY); + + // Copy the background of the main DC to the destination. + BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, dc, Rect.Left, Rect.Top, + SRCCOPY); + + // Mask out the places where the bitmap will be placed. + BitBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdcObject, 0, 0, SRCAND); + + // Mask out the transparent colored pixels on the bitmap. +// BitBlt(hdcTemp, 0, 0, ptSize.x, ptSize.y, hdcBack, 0, 0, SRCAND); + StretchBlt(hdcTemp, 0, 0, OrgSize.x, OrgSize.y, hdcBack, 0, 0, + PtSize.x, PtSize.y, SRCAND); + + // XOR the bitmap with the background on the destination DC. + StretchBlt(hdcMem, 0, 0, ptSize.x, ptSize.y, hdcTemp, 0, 0, + OrgSize.x, OrgSize.y, SRCPAINT); + + // Copy the destination to the screen. + BitBlt(dc, Rect.Left, Rect.Top, ptSize.x, ptSize.y, hdcMem, 0, 0, + SRCCOPY); + + // Delete the memory bitmaps. + DeleteObject(SelectObject(hdcBack, bmBackOld)); + DeleteObject(SelectObject(hdcObject, bmObjectOld)); + DeleteObject(SelectObject(hdcMem, bmMemOld)); + DeleteObject(SelectObject(hdcTemp, OldBitmap)); + + // Delete the memory DCs. + DeleteDC(hdcMem); + DeleteDC(hdcBack); + DeleteDC(hdcObject); + DeleteDC(hdcTemp); +end; + +{Make the table for a fast CRC.} +procedure make_crc_table; +var + c: Cardinal; + n, k: Integer; +begin + + {fill the crc table} + for n := 0 to 255 do + begin + c := Cardinal(n); + for k := 0 to 7 do + begin + if Boolean(c and 1) then + c := $edb88320 xor (c shr 1) + else + c := c shr 1; + end; + crc_table[n] := c; + end; + + {The table has already being computated} + crc_table_computed := true; +end; + +{Update a running CRC with the bytes buf[0..len-1]--the CRC + should be initialized to all 1's, and the transmitted value + is the 1's complement of the final running CRC (see the + crc() routine below)).} +function update_crc(crc: {$IFNDEF DelphiBuilder3Less}Cardinal{$ELSE}Integer + {$ENDIF}; buf: pByteArray; len: Integer): Cardinal; +var + c: Cardinal; + n: Integer; +begin + c := crc; + + {Create the crc table in case it has not being computed yet} + if not crc_table_computed then make_crc_table; + + {Update} + for n := 0 to len - 1 do + c := crc_table[(c XOR buf^[n]) and $FF] XOR (c shr 8); + + {Returns} + Result := c; +end; + +{$IFNDEF UseDelphi} + function FileExists(Filename: String): Boolean; + var + FindFile: THandle; + FindData: TWin32FindData; + begin + FindFile := FindFirstFile(PChar(Filename), FindData); + Result := FindFile <> INVALID_HANDLE_VALUE; + if Result then Windows.FindClose(FindFile); + end; + + +{$ENDIF} + +{$IFNDEF UseDelphi} + {Exception implementation} + constructor Exception.Create(Msg: String); + begin + end; +{$ENDIF} + +{Calculates the paeth predictor} +function PaethPredictor(a, b, c: Byte): Byte; +var + pa, pb, pc: Integer; +begin + { a = left, b = above, c = upper left } + pa := abs(b - c); { distances to a, b, c } + pb := abs(a - c); + pc := abs(a + b - c * 2); + + { return nearest of a, b, c, breaking ties in order a, b, c } + if (pa <= pb) and (pa <= pc) then + Result := a + else + if pb <= pc then + Result := b + else + Result := c; +end; + +{Invert bytes using assembly} +function ByteSwap(const a: integer): integer; +asm + bswap eax +end; +function ByteSwap16(inp:word): word; +asm + bswap eax + shr eax, 16 +end; + +{Calculates number of bytes for the number of pixels using the} +{color mode in the paramenter} +function BytesForPixels(const Pixels: Integer; const ColorType, + BitDepth: Byte): Integer; +begin + case ColorType of + {Palette and grayscale contains a single value, for palette} + {an value of size 2^bitdepth pointing to the palette index} + {and grayscale the value from 0 to 2^bitdepth with color intesity} + COLOR_GRAYSCALE, COLOR_PALETTE: + Result := (Pixels * BitDepth + 7) div 8; + {RGB contains 3 values R, G, B with size 2^bitdepth each} + COLOR_RGB: + Result := (Pixels * BitDepth * 3) div 8; + {Contains one value followed by alpha value booth size 2^bitdepth} + COLOR_GRAYSCALEALPHA: + Result := (Pixels * BitDepth * 2) div 8; + {Contains four values size 2^bitdepth, Red, Green, Blue and alpha} + COLOR_RGBALPHA: + Result := (Pixels * BitDepth * 4) div 8; + else + Result := 0; + end {case ColorType} +end; + +type + pChunkClassInfo = ^TChunkClassInfo; + TChunkClassInfo = record + ClassName: TChunkClass; + end; + +{Register a chunk type} +procedure RegisterChunk(ChunkClass: TChunkClass); +var + NewClass: pChunkClassInfo; +begin + {In case the list object has not being created yet} + if ChunkClasses = nil then ChunkClasses := TPngPointerList.Create(nil); + + {Add this new class} + new(NewClass); + NewClass^.ClassName := ChunkClass; + ChunkClasses.Add(NewClass); +end; + +{Free chunk class list} +procedure FreeChunkClassList; +var + i: Integer; +begin + if (ChunkClasses <> nil) then + begin + FOR i := 0 TO ChunkClasses.Count - 1 do + Dispose(pChunkClassInfo(ChunkClasses.Item[i])); + ChunkClasses.Free; + end; +end; + +{Registering of common chunk classes} +procedure RegisterCommonChunks; +begin + {Important chunks} + RegisterChunk(TChunkIEND); + RegisterChunk(TChunkIHDR); + RegisterChunk(TChunkIDAT); + RegisterChunk(TChunkPLTE); + RegisterChunk(TChunkgAMA); + RegisterChunk(TChunktRNS); + + {Not so important chunks} + RegisterChunk(TChunktIME); + RegisterChunk(TChunktEXt); + RegisterChunk(TChunkzTXt); +end; + +{Creates a new chunk of this class} +function CreateClassChunk(Owner: TPngObject; Name: TChunkName): TChunk; +var + i : Integer; + NewChunk: TChunkClass; +begin + {Looks for this chunk} + NewChunk := TChunk; {In case there is no registered class for this} + + {Looks for this class in all registered chunks} + if Assigned(ChunkClasses) then + FOR i := 0 TO ChunkClasses.Count - 1 DO + begin + if pChunkClassInfo(ChunkClasses.Item[i])^.ClassName.GetName = Name then + begin + NewChunk := pChunkClassInfo(ChunkClasses.Item[i])^.ClassName; + break; + end; + end; + + {Returns chunk class} + Result := NewChunk.Create(Owner); + Result.fName := Name; +end; + +{ZLIB support} + +const + ZLIBAllocate = High(Word); + +{Initializes ZLIB for decompression} +function ZLIBInitInflate(Stream: TStream): TZStreamRec2; +begin + {Fill record} + Fillchar(Result, SIZEOF(TZStreamRec2), #0); + + {Set internal record information} + with Result do + begin + GetMem(Data, ZLIBAllocate); + fStream := Stream; + end; + + {Init decompression} + InflateInit_(Result.zlib, zlib_version, SIZEOF(TZStreamRec)); +end; + +{Initializes ZLIB for compression} +function ZLIBInitDeflate(Stream: TStream; + Level: TCompressionlevel; Size: Cardinal): TZStreamRec2; +begin + {Fill record} + Fillchar(Result, SIZEOF(TZStreamRec2), #0); + + {Set internal record information} + with Result, ZLIB do + begin + GetMem(Data, Size); + fStream := Stream; + next_out := Data; + avail_out := Size; + end; + + {Inits compression} + deflateInit_(Result.zlib, Level, zlib_version, sizeof(TZStreamRec)); +end; + +{Terminates ZLIB for compression} +procedure ZLIBTerminateDeflate(var ZLIBStream: TZStreamRec2); +begin + {Terminates decompression} + DeflateEnd(ZLIBStream.zlib); + {Free internal record} + FreeMem(ZLIBStream.Data, ZLIBAllocate); +end; + +{Terminates ZLIB for decompression} +procedure ZLIBTerminateInflate(var ZLIBStream: TZStreamRec2); +begin + {Terminates decompression} + InflateEnd(ZLIBStream.zlib); + {Free internal record} + FreeMem(ZLIBStream.Data, ZLIBAllocate); +end; + +{Decompresses ZLIB into a memory address} +function DecompressZLIB(const Input: Pointer; InputSize: Integer; + var Output: Pointer; var OutputSize: Integer; + var ErrorOutput: String): Boolean; +var + StreamRec : TZStreamRec; + Buffer : Array[Byte] of Byte; + InflateRet: Integer; +begin + with StreamRec do + begin + {Initializes} + Result := True; + OutputSize := 0; + + {Prepares the data to decompress} + FillChar(StreamRec, SizeOf(TZStreamRec), #0); + InflateInit_(StreamRec, zlib_version, SIZEOF(TZStreamRec)); + next_in := Input; + avail_in := InputSize; + + {Decodes data} + repeat + {In case it needs an output buffer} + if (avail_out = 0) then + begin + next_out := @Buffer; + avail_out := SizeOf(Buffer); + end {if (avail_out = 0)}; + + {Decompress and put in output} + InflateRet := inflate(StreamRec, 0); + if (InflateRet = Z_STREAM_END) or (InflateRet = 0) then + begin + {Reallocates output buffer} + inc(OutputSize, total_out); + if Output = nil then + GetMem(Output, OutputSize) else ReallocMem(Output, OutputSize); + {Copies the new data} + CopyMemory(Ptr(Longint(Output) + OutputSize - total_out), + @Buffer, total_out); + end {if (InflateRet = Z_STREAM_END) or (InflateRet = 0)} + {Now tests for errors} + else if InflateRet < 0 then + begin + Result := False; + ErrorOutput := StreamRec.msg; + InflateEnd(StreamRec); + Exit; + end {if InflateRet < 0} + until InflateRet = Z_STREAM_END; + + {Terminates decompression} + InflateEnd(StreamRec); + end {with StreamRec} + +end; + +{Compresses ZLIB into a memory address} +function CompressZLIB(Input: Pointer; InputSize, CompressionLevel: Integer; + var Output: Pointer; var OutputSize: Integer; + var ErrorOutput: String): Boolean; +var + StreamRec : TZStreamRec; + Buffer : Array[Byte] of Byte; + DeflateRet: Integer; +begin + with StreamRec do + begin + Result := True; {By default returns TRUE as everything might have gone ok} + OutputSize := 0; {Initialize} + {Prepares the data to compress} + FillChar(StreamRec, SizeOf(TZStreamRec), #0); + DeflateInit_(StreamRec, CompressionLevel,zlib_version, SIZEOF(TZStreamRec)); + + next_in := Input; + avail_in := InputSize; + + while avail_in > 0 do + begin + {When it needs new buffer to stores the compressed data} + if avail_out = 0 then + begin + {Restore buffer} + next_out := @Buffer; + avail_out := SizeOf(Buffer); + end {if avail_out = 0}; + + {Compresses} + DeflateRet := deflate(StreamRec, Z_FINISH); + + if (DeflateRet = Z_STREAM_END) or (DeflateRet = 0) then + begin + {Updates the output memory} + inc(OutputSize, total_out); + if Output = nil then + GetMem(Output, OutputSize) else ReallocMem(Output, OutputSize); + + {Copies the new data} + CopyMemory(Ptr(Longint(Output) + OutputSize - total_out), + @Buffer, total_out); + end {if (InflateRet = Z_STREAM_END) or (InflateRet = 0)} + {Now tests for errors} + else if DeflateRet < 0 then + begin + Result := False; + ErrorOutput := StreamRec.msg; + DeflateEnd(StreamRec); + Exit; + end {if InflateRet < 0} + + end {while avail_in > 0}; + + {Finishes compressing} + DeflateEnd(StreamRec); + end {with StreamRec} + +end; + +{TPngPointerList implementation} + +{Object being created} +constructor TPngPointerList.Create(AOwner: TPNGObject); +begin + inherited Create; {Let ancestor work} + {Holds owner} + fOwner := AOwner; + {Memory pointer not being used yet} + fMemory := nil; + {No items yet} + fCount := 0; +end; + +{Removes value from the list} +function TPngPointerList.Remove(Value: Pointer): Pointer; +var + I, Position: Integer; +begin + {Gets item position} + Position := -1; + FOR I := 0 TO Count - 1 DO + if Value = Item[I] then Position := I; + {In case a match was found} + if Position >= 0 then + begin + Result := Item[Position]; {Returns pointer} + {Remove item and move memory} + Dec(fCount); + if Position < Integer(FCount) then + System.Move(fMemory^[Position + 1], fMemory^[Position], + (Integer(fCount) - Position) * SizeOf(Pointer)); + end {if Position >= 0} else Result := nil +end; + +{Add a new value in the list} +procedure TPngPointerList.Add(Value: Pointer); +begin + Count := Count + 1; + Item[Count - 1] := Value; +end; + + +{Object being destroyed} +destructor TPngPointerList.Destroy; +begin + {Release memory if needed} + if fMemory <> nil then + FreeMem(fMemory, fCount * sizeof(Pointer)); + + {Free things} + inherited Destroy; +end; + +{Returns one item from the list} +function TPngPointerList.GetItem(Index: Cardinal): Pointer; +begin + if (Index <= Count - 1) then + Result := fMemory[Index] + else + {In case it's out of bounds} + Result := nil; +end; + +{Inserts a new item in the list} +procedure TPngPointerList.Insert(Value: Pointer; Position: Cardinal); +begin + if (Position < Count) then + begin + {Increase item count} + SetSize(Count + 1); + {Move other pointers} + if Position < Count then + System.Move(fMemory^[Position], fMemory^[Position + 1], + (Count - Position - 1) * SizeOf(Pointer)); + {Sets item} + Item[Position] := Value; + end; +end; + +{Sets one item from the list} +procedure TPngPointerList.SetItem(Index: Cardinal; const Value: Pointer); +begin + {If index is in bounds, set value} + if (Index <= Count - 1) then + fMemory[Index] := Value +end; + +{This method resizes the list} +procedure TPngPointerList.SetSize(const Size: Cardinal); +begin + {Sets the size} + if (fMemory = nil) and (Size > 0) then + GetMem(fMemory, Size * SIZEOF(Pointer)) + else + if Size > 0 then {Only realloc if the new size is greater than 0} + ReallocMem(fMemory, Size * SIZEOF(Pointer)) + else + {In case user is resize to 0 items} + begin + FreeMem(fMemory); + fMemory := nil; + end; + {Update count} + fCount := Size; +end; + +{TPNGList implementation} + +{Removes an item} +procedure TPNGList.RemoveChunk(Chunk: TChunk); +begin + Remove(Chunk); + Chunk.Free +end; + +{Add a new item} +function TPNGList.Add(ChunkClass: TChunkClass): TChunk; +var + IHDR: TChunkIHDR; + IEND: TChunkIEND; + + IDAT: TChunkIDAT; + PLTE: TChunkPLTE; +begin + Result := nil; {Default result} + {Adding these is not allowed} + if (ChunkClass = TChunkIHDR) or (ChunkClass = TChunkIDAT) or + (ChunkClass = TChunkPLTE) or (ChunkClass = TChunkIEND) then + fOwner.RaiseError(EPngError, EPNGCannotAddChunkText) + {Two of these is not allowed} + else if ((ChunkClass = TChunkgAMA) and (ItemFromClass(TChunkgAMA) <> nil)) or + ((ChunkClass = TChunktRNS) and (ItemFromClass(TChunktRNS) <> nil)) then + fOwner.RaiseError(EPngError, EPNGCannotAddChunkText) + {There must have an IEND and IHDR chunk} + else if (ItemFromClass(TChunkIEND) = nil) or + (ItemFromClass(TChunkIHDR) = nil) then + fOwner.RaiseError(EPngError, EPNGCannotAddInvalidImageText) + else + begin + {Get common chunks} + IHDR := ItemFromClass(TChunkIHDR) as TChunkIHDR; + IEND := ItemFromClass(TChunkIEND) as TChunkIEND; + {Create new chunk} + Result := ChunkClass.Create(Owner); + {Add to the list} + if (ChunkClass = TChunkgAMA) then + Insert(Result, IHDR.Index + 1) + {Transparency chunk (fix by Ian Boyd)} + else if (ChunkClass = TChunktRNS) then + begin + {Transparecy chunk must be after PLTE; before IDAT} + IDAT := ItemFromClass(TChunkIDAT) as TChunkIDAT; + PLTE := ItemFromClass(TChunkPLTE) as TChunkPLTE; + + if Assigned(PLTE) then + Insert(Result, PLTE.Index + 1) + else if Assigned(IDAT) then + Insert(Result, IDAT.Index) + else + Insert(Result, IHDR.Index + 1) + end + else {All other chunks} + Insert(Result, IEND.Index); + end {if} +end; + +{Returns item from the list} +function TPNGList.GetItem(Index: Cardinal): TChunk; +begin + Result := inherited GetItem(Index); +end; + +{Returns first item from the list using the class from parameter} +function TPNGList.ItemFromClass(ChunkClass: TChunkClass): TChunk; +var + i: Integer; +begin + Result := nil; {Initial result} + FOR i := 0 TO Count - 1 DO + {Test if this item has the same class} + if Item[i] is ChunkClass then + begin + {Returns this item and exit} + Result := Item[i]; + break; + end {if} +end; + +{$IFNDEF UseDelphi} + + {TStream implementation} + + {Copies all from another stream} + function TStream.CopyFrom(Source: TStream; Count: Cardinal): Cardinal; + const + MaxBytes = $f000; + var + Buffer: PChar; + BufSize, N: Cardinal; + begin + {If count is zero, copy everything from Source} + if Count = 0 then + begin + Source.Seek(0, soFromBeginning); + Count := Source.Size; + end; + + Result := Count; {Returns the number of bytes readed} + {Allocates memory} + if Count > MaxBytes then BufSize := MaxBytes else BufSize := Count; + GetMem(Buffer, BufSize); + + {Copy memory} + while Count > 0 do + begin + if Count > BufSize then N := BufSize else N := Count; + Source.Read(Buffer^, N); + Write(Buffer^, N); + dec(Count, N); + end; + + {Deallocates memory} + FreeMem(Buffer, BufSize); + end; + +{Set current stream position} +procedure TStream.SetPosition(const Value: Longint); +begin + Seek(Value, soFromBeginning); +end; + +{Returns position} +function TStream.GetPosition: Longint; +begin + Result := Seek(0, soFromCurrent); +end; + + {Returns stream size} +function TStream.GetSize: Longint; + var + Pos: Cardinal; + begin + Pos := Seek(0, soFromCurrent); + Result := Seek(0, soFromEnd); + Seek(Pos, soFromCurrent); + end; + + {TFileStream implementation} + + {Filestream object being created} + constructor TFileStream.Create(Filename: String; Mode: TFileStreamModeSet); + {Makes file mode} + function OpenMode: DWORD; + begin + Result := 0; + if fsmRead in Mode then Result := GENERIC_READ; + if (fsmWrite in Mode) or (fsmCreate in Mode) then + Result := Result OR GENERIC_WRITE; + end; + const + IsCreate: Array[Boolean] of Integer = (OPEN_ALWAYS, CREATE_ALWAYS); + begin + {Call ancestor} + inherited Create; + + {Create handle} + fHandle := CreateFile(PChar(Filename), OpenMode, FILE_SHARE_READ or + FILE_SHARE_WRITE, nil, IsCreate[fsmCreate in Mode], 0, 0); + {Store mode} + FileMode := Mode; + end; + + {Filestream object being destroyed} + destructor TFileStream.Destroy; + begin + {Terminates file and close} + if FileMode = [fsmWrite] then + SetEndOfFile(fHandle); + CloseHandle(fHandle); + + {Call ancestor} + inherited Destroy; + end; + + {Writes data to the file} + function TFileStream.Write(const Buffer; Count: Longint): Cardinal; + begin + if not WriteFile(fHandle, Buffer, Count, Result, nil) then + Result := 0; + end; + + {Reads data from the file} + function TFileStream.Read(var Buffer; Count: Longint): Cardinal; + begin + if not ReadFile(fHandle, Buffer, Count, Result, nil) then + Result := 0; + end; + + {Seeks the file position} + function TFileStream.Seek(Offset: Integer; Origin: Word): Longint; + begin + Result := SetFilePointer(fHandle, Offset, nil, Origin); + end; + + {Sets the size of the file} + procedure TFileStream.SetSize(const Value: Longint); + begin + Seek(Value, soFromBeginning); + SetEndOfFile(fHandle); + end; + + {TResourceStream implementation} + + {Creates the resource stream} + constructor TResourceStream.Create(Instance: HInst; const ResName: String; + ResType: PChar); + var + ResID: HRSRC; + ResGlobal: HGlobal; + begin + {Obtains the resource ID} + ResID := FindResource(hInstance, PChar(ResName), RT_RCDATA); + if ResID = 0 then raise EPNGError.Create(''); + {Obtains memory and size} + ResGlobal := LoadResource(hInstance, ResID); + Size := SizeOfResource(hInstance, ResID); + Memory := LockResource(ResGlobal); + if (ResGlobal = 0) or (Memory = nil) then EPNGError.Create(''); + end; + + + {Setting resource stream size is not supported} + procedure TResourceStream.SetSize(const Value: Integer); + begin + end; + + {Writing into a resource stream is not supported} + function TResourceStream.Write(const Buffer; Count: Integer): Cardinal; + begin + Result := 0; + end; + + {Reads data from the stream} + function TResourceStream.Read(var Buffer; Count: Integer): Cardinal; + begin + //Returns data + CopyMemory(@Buffer, Ptr(Longint(Memory) + Position), Count); + //Update position + inc(Position, Count); + //Returns + Result := Count; + end; + + {Seeks data} + function TResourceStream.Seek(Offset: Integer; Origin: Word): Longint; + begin + {Move depending on the origin} + case Origin of + soFromBeginning: Position := Offset; + soFromCurrent: inc(Position, Offset); + soFromEnd: Position := Size + Offset; + end; + + {Returns the current position} + Result := Position; + end; + +{$ENDIF} + +{TChunk implementation} + +{Resizes the data} +procedure TChunk.ResizeData(const NewSize: Cardinal); +begin + fDataSize := NewSize; + ReallocMem(fData, NewSize + 1); +end; + +{Returns index from list} +function TChunk.GetIndex: Integer; +var + i: Integer; +begin + Result := -1; {Avoiding warnings} + {Searches in the list} + FOR i := 0 TO Owner.Chunks.Count - 1 DO + if Owner.Chunks.Item[i] = Self then + begin + {Found match} + Result := i; + exit; + end {for i} +end; + +{Returns pointer to the TChunkIHDR} +function TChunk.GetHeader: TChunkIHDR; +begin + Result := Owner.Chunks.Item[0] as TChunkIHDR; +end; + +{Assigns from another TChunk} +procedure TChunk.Assign(Source: TChunk); +begin + {Copy properties} + fName := Source.fName; + {Set data size and realloc} + ResizeData(Source.fDataSize); + + {Copy data (if there's any)} + if fDataSize > 0 then CopyMemory(fData, Source.fData, fDataSize); +end; + +{Chunk being created} +constructor TChunk.Create(Owner: TPngObject); +var + ChunkName: String; +begin + {Ancestor create} + inherited Create; + + {If it's a registered class, set the chunk name based on the class} + {name. For instance, if the class name is TChunkgAMA, the GAMA part} + {will become the chunk name} + ChunkName := Copy(ClassName, Length('TChunk') + 1, Length(ClassName)); + if Length(ChunkName) = 4 then CopyMemory(@fName[0], @ChunkName[1], 4); + + {Initialize data holder} + GetMem(fData, 1); + fDataSize := 0; + {Record owner} + fOwner := Owner; +end; + +{Chunk being destroyed} +destructor TChunk.Destroy; +begin + {Free data holder} + FreeMem(fData, fDataSize + 1); + {Let ancestor destroy} + inherited Destroy; +end; + +{Returns the chunk name 1} +function TChunk.GetChunkName: String; +begin + Result := fName +end; + +{Returns the chunk name 2} +class function TChunk.GetName: String; +begin + {For avoid writing GetName for each TChunk descendent, by default for} + {classes which don't declare GetName, it will look for the class name} + {to extract the chunk kind. Example, if the class name is TChunkIEND } + {this method extracts and returns IEND} + Result := Copy(ClassName, Length('TChunk') + 1, Length(ClassName)); +end; + +{Saves the data to the stream} +function TChunk.SaveData(Stream: TStream): Boolean; +var + ChunkSize, ChunkCRC: Cardinal; +begin + {First, write the size for the following data in the chunk} + ChunkSize := ByteSwap(DataSize); + Stream.Write(ChunkSize, 4); + {The chunk name} + Stream.Write(fName, 4); + {If there is data for the chunk, write it} + if DataSize > 0 then Stream.Write(Data^, DataSize); + {Calculates and write CRC} + ChunkCRC := update_crc($ffffffff, @fName[0], 4); + ChunkCRC := Byteswap(update_crc(ChunkCRC, Data, DataSize) xor $ffffffff); + Stream.Write(ChunkCRC, 4); + + {Returns that everything went ok} + Result := TRUE; +end; + +{Saves the chunk to the stream} +function TChunk.SaveToStream(Stream: TStream): Boolean; +begin + Result := SaveData(Stream) +end; + + +{Loads the chunk from a stream} +function TChunk.LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; +var + CheckCRC: Cardinal; + {$IFDEF CheckCRC}RightCRC: Cardinal;{$ENDIF} +begin + {Copies data from source} + ResizeData(Size); + if Size > 0 then Stream.Read(fData^, Size); + {Reads CRC} + Stream.Read(CheckCRC, 4); + CheckCrc := ByteSwap(CheckCRC); + + {Check if crc readed is valid} + {$IFDEF CheckCRC} + RightCRC := update_crc($ffffffff, @ChunkName[0], 4); + RightCRC := update_crc(RightCRC, fData, Size) xor $ffffffff; + Result := RightCRC = CheckCrc; + + {Handle CRC error} + if not Result then + begin + {In case it coult not load chunk} + Owner.RaiseError(EPngInvalidCRC, EPngInvalidCRCText); + exit; + end + {$ELSE}Result := TRUE; {$ENDIF} + +end; + +{TChunktIME implementation} + +{Chunk being loaded from a stream} +function TChunktIME.LoadFromStream(Stream: TStream; + const ChunkName: TChunkName; Size: Integer): Boolean; +begin + {Let ancestor load the data} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + if not Result or (Size <> 7) then exit; {Size must be 7} + + {Reads data} + fYear := ((pByte(Longint(Data) )^) * 256)+ (pByte(Longint(Data) + 1)^); + fMonth := pByte(Longint(Data) + 2)^; + fDay := pByte(Longint(Data) + 3)^; + fHour := pByte(Longint(Data) + 4)^; + fMinute := pByte(Longint(Data) + 5)^; + fSecond := pByte(Longint(Data) + 6)^; +end; + +{Saving the chunk to a stream} +function TChunktIME.SaveToStream(Stream: TStream): Boolean; +begin + {Update data} + ResizeData(7); {Make sure the size is 7} + pWord(Data)^ := Year; + pByte(Longint(Data) + 2)^ := Month; + pByte(Longint(Data) + 3)^ := Day; + pByte(Longint(Data) + 4)^ := Hour; + pByte(Longint(Data) + 5)^ := Minute; + pByte(Longint(Data) + 6)^ := Second; + + {Let inherited save data} + Result := inherited SaveToStream(Stream); +end; + +{TChunkztXt implementation} + +{Loading the chunk from a stream} +function TChunkzTXt.LoadFromStream(Stream: TStream; + const ChunkName: TChunkName; Size: Integer): Boolean; +var + ErrorOutput: String; + CompressionMethod: Byte; + Output: Pointer; + OutputSize: Integer; +begin + {Load data from stream and validate} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + if not Result or (Size < 4) then exit; + fKeyword := PChar(Data); {Get keyword and compression method bellow} + CompressionMethod := pByte(Longint(fKeyword) + Length(fKeyword))^; + fText := ''; + + {In case the compression is 0 (only one accepted by specs), reads it} + if CompressionMethod = 0 then + begin + Output := nil; + if DecompressZLIB(PChar(Longint(Data) + Length(fKeyword) + 2), + Size - Length(fKeyword) - 2, Output, OutputSize, ErrorOutput) then + begin + SetLength(fText, OutputSize); + CopyMemory(@fText[1], Output, OutputSize); + end {if DecompressZLIB(...}; + FreeMem(Output); + end {if CompressionMethod = 0} + +end; + +{Saving the chunk to a stream} +function TChunkztXt.SaveToStream(Stream: TStream): Boolean; +var + Output: Pointer; + OutputSize: Integer; + ErrorOutput: String; +begin + Output := nil; {Initializes output} + if fText = '' then fText := ' '; + + {Compresses the data} + if CompressZLIB(@fText[1], Length(fText), Owner.CompressionLevel, Output, + OutputSize, ErrorOutput) then + begin + {Size is length from keyword, plus a null character to divide} + {plus the compression method, plus the length of the text (zlib compressed)} + ResizeData(Length(fKeyword) + 2 + OutputSize); + + Fillchar(Data^, DataSize, #0); + {Copies the keyword data} + if Keyword <> '' then + CopyMemory(Data, @fKeyword[1], Length(Keyword)); + {Compression method 0 (inflate/deflate)} + pByte(Ptr(Longint(Data) + Length(Keyword) + 1))^ := 0; + if OutputSize > 0 then + CopyMemory(Ptr(Longint(Data) + Length(Keyword) + 2), Output, OutputSize); + + {Let ancestor calculate crc and save} + Result := SaveData(Stream); + end {if CompressZLIB(...} else Result := False; + + {Frees output} + if Output <> nil then FreeMem(Output) +end; + +{TChunktEXt implementation} + +{Assigns from another text chunk} +procedure TChunktEXt.Assign(Source: TChunk); +begin + fKeyword := TChunktEXt(Source).fKeyword; + fText := TChunktEXt(Source).fText; +end; + +{Loading the chunk from a stream} +function TChunktEXt.LoadFromStream(Stream: TStream; + const ChunkName: TChunkName; Size: Integer): Boolean; +begin + {Load data from stream and validate} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + if not Result or (Size < 3) then exit; + {Get text} + fKeyword := PChar(Data); + SetLength(fText, Size - Length(fKeyword) - 1); + CopyMemory(@fText[1], Ptr(Longint(Data) + Length(fKeyword) + 1), + Length(fText)); +end; + +{Saving the chunk to a stream} +function TChunktEXt.SaveToStream(Stream: TStream): Boolean; +begin + {Size is length from keyword, plus a null character to divide} + {plus the length of the text} + ResizeData(Length(fKeyword) + 1 + Length(fText)); + Fillchar(Data^, DataSize, #0); + {Copy data} + if Keyword <> '' then + CopyMemory(Data, @fKeyword[1], Length(Keyword)); + if Text <> '' then + CopyMemory(Ptr(Longint(Data) + Length(Keyword) + 1), @fText[1], + Length(Text)); + {Let ancestor calculate crc and save} + Result := inherited SaveToStream(Stream); +end; + + +{TChunkIHDR implementation} + +{Chunk being created} +constructor TChunkIHDR.Create(Owner: TPngObject); +begin + {Call inherited} + inherited Create(Owner); + {Prepare pointers} + ImageHandle := 0; + ImageDC := 0; +end; + +{Chunk being destroyed} +destructor TChunkIHDR.Destroy; +begin + {Free memory} + FreeImageData(); + + {Calls TChunk destroy} + inherited Destroy; +end; + +{Assigns from another IHDR chunk} +procedure TChunkIHDR.Assign(Source: TChunk); +begin + {Copy the IHDR data} + if Source is TChunkIHDR then + begin + {Copy IHDR values} + IHDRData := TChunkIHDR(Source).IHDRData; + + {Prepare to hold data by filling BitmapInfo structure and} + {resizing ImageData and ImageAlpha memory allocations} + PrepareImageData(); + + {Copy image data} + CopyMemory(ImageData, TChunkIHDR(Source).ImageData, + BytesPerRow * Integer(Height)); + CopyMemory(ImageAlpha, TChunkIHDR(Source).ImageAlpha, + Integer(Width) * Integer(Height)); + + {Copy palette colors} + BitmapInfo.bmiColors := TChunkIHDR(Source).BitmapInfo.bmiColors; + end + else + Owner.RaiseError(EPNGError, EPNGCannotAssignChunkText); +end; + +{Release allocated image data} +procedure TChunkIHDR.FreeImageData; +begin + {Free old image data} + if ImageHandle <> 0 then DeleteObject(ImageHandle); + if ImageDC <> 0 then DeleteDC(ImageDC); + if ImageAlpha <> nil then FreeMem(ImageAlpha); + {$IFDEF Store16bits} + if ExtraImageData <> nil then FreeMem(ExtraImageData); + {$ENDIF} + ImageHandle := 0; ImageDC := 0; ImageAlpha := nil; ImageData := nil; +end; + +{Chunk being loaded from a stream} +function TChunkIHDR.LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; +begin + {Let TChunk load it} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + if not Result then Exit; + + {Now check values} + {Note: It's recommended by png specification to make sure that the size} + {must be 13 bytes to be valid, but some images with 14 bytes were found} + {which could be loaded by internet explorer and other tools} + if (fDataSize < SIZEOF(TIHdrData)) then + begin + {Ihdr must always have at least 13 bytes} + Result := False; + Owner.RaiseError(EPNGInvalidIHDR, EPNGInvalidIHDRText); + exit; + end; + + {Everything ok, reads IHDR} + IHDRData := pIHDRData(fData)^; + IHDRData.Width := ByteSwap(IHDRData.Width); + IHDRData.Height := ByteSwap(IHDRData.Height); + + {The width and height must not be larger than 65535 pixels} + if (IHDRData.Width > High(Word)) or (IHDRData.Height > High(Word)) then + begin + Result := False; + Owner.RaiseError(EPNGSizeExceeds, EPNGSizeExceedsText); + exit; + end {if IHDRData.Width > High(Word)}; + {Compression method must be 0 (inflate/deflate)} + if (IHDRData.CompressionMethod <> 0) then + begin + Result := False; + Owner.RaiseError(EPNGUnknownCompression, EPNGUnknownCompressionText); + exit; + end; + {Interlace must be either 0 (none) or 7 (adam7)} + if (IHDRData.InterlaceMethod <> 0) and (IHDRData.InterlaceMethod <> 1) then + begin + Result := False; + Owner.RaiseError(EPNGUnknownInterlace, EPNGUnknownInterlaceText); + exit; + end; + + {Updates owner properties} + Owner.InterlaceMethod := TInterlaceMethod(IHDRData.InterlaceMethod); + + {Prepares data to hold image} + PrepareImageData(); +end; + +{Saving the IHDR chunk to a stream} +function TChunkIHDR.SaveToStream(Stream: TStream): Boolean; +begin + {Ignore 2 bits images} + if BitDepth = 2 then BitDepth := 4; + + {It needs to do is update the data with the IHDR data} + {structure containing the write values} + ResizeData(SizeOf(TIHDRData)); + pIHDRData(fData)^ := IHDRData; + {..byteswap 4 byte types} + pIHDRData(fData)^.Width := ByteSwap(pIHDRData(fData)^.Width); + pIHDRData(fData)^.Height := ByteSwap(pIHDRData(fData)^.Height); + {..update interlace method} + pIHDRData(fData)^.InterlaceMethod := Byte(Owner.InterlaceMethod); + {..and then let the ancestor SaveToStream do the hard work} + Result := inherited SaveToStream(Stream); +end; + +{Resizes the image data to fill the color type, bit depth, } +{width and height parameters} +procedure TChunkIHDR.PrepareImageData(); + + {Set the bitmap info} + procedure SetInfo(const Bitdepth: Integer; const Palette: Boolean); + begin + + {Copy if the bitmap contain palette entries} + HasPalette := Palette; + {Initialize the structure with zeros} + fillchar(BitmapInfo, sizeof(BitmapInfo), #0); + {Fill the strucutre} + with BitmapInfo.bmiHeader do + begin + biSize := sizeof(TBitmapInfoHeader); + biHeight := Height; + biWidth := Width; + biPlanes := 1; + biBitCount := BitDepth; + biCompression := BI_RGB; + end {with BitmapInfo.bmiHeader} + end; +begin + {Prepare bitmap info header} + Fillchar(BitmapInfo, sizeof(TMaxBitmapInfo), #0); + {Release old image data} + FreeImageData(); + + {Obtain number of bits for each pixel} + case ColorType of + COLOR_GRAYSCALE, COLOR_PALETTE, COLOR_GRAYSCALEALPHA: + case BitDepth of + {These are supported by windows} + 1, 4, 8: SetInfo(BitDepth, TRUE); + {2 bits for each pixel is not supported by windows bitmap} + 2 : SetInfo(4, TRUE); + {Also 16 bits (2 bytes) for each pixel is not supported} + {and should be transormed into a 8 bit grayscale} + 16 : SetInfo(8, TRUE); + end; + {Only 1 byte (8 bits) is supported} + COLOR_RGB, COLOR_RGBALPHA: SetInfo(24, FALSE); + end {case ColorType}; + {Number of bytes for each scanline} + BytesPerRow := (((BitmapInfo.bmiHeader.biBitCount * Width) + 31) + and not 31) div 8; + + {Build array for alpha information, if necessary} + if (ColorType = COLOR_RGBALPHA) or (ColorType = COLOR_GRAYSCALEALPHA) then + begin + GetMem(ImageAlpha, Integer(Width) * Integer(Height)); + FillChar(ImageAlpha^, Integer(Width) * Integer(Height), #0); + end; + + {Build array for extra byte information} + {$IFDEF Store16bits} + if (BitDepth = 16) then + begin + GetMem(ExtraImageData, BytesPerRow * Integer(Height)); + FillChar(ExtraImageData^, BytesPerRow * Integer(Height), #0); + end; + {$ENDIF} + + {Creates the image to hold the data, CreateDIBSection does a better} + {work in allocating necessary memory} + ImageDC := CreateCompatibleDC(0); + ImageHandle := CreateDIBSection(ImageDC, pBitmapInfo(@BitmapInfo)^, + DIB_RGB_COLORS, ImageData, 0, 0); + + {Clears the old palette (if any)} + with Owner do + if TempPalette <> 0 then + begin + DeleteObject(TempPalette); + TempPalette := 0; + end {with Owner, if TempPalette <> 0}; + + {Build array and allocate bytes for each row} + zeromemory(ImageData, BytesPerRow * Integer(Height)); +end; + +{TChunktRNS implementation} + +{$IFNDEF UseDelphi} +function CompareMem(P1, P2: pByte; const Size: Integer): Boolean; +var i: Integer; +begin + Result := True; + for i := 1 to Size do + begin + if P1^ <> P2^ then Result := False; + inc(P1); inc(P2); + end {for i} +end; +{$ENDIF} + +{Sets the transpararent color} +procedure TChunktRNS.SetTransparentColor(const Value: ColorRef); +var + i: Byte; + LookColor: TRGBQuad; +begin + {Clears the palette values} + Fillchar(PaletteValues, SizeOf(PaletteValues), #0); + {Sets that it uses bit transparency} + fBitTransparency := True; + + + {Depends on the color type} + with Header do + case ColorType of + COLOR_GRAYSCALE: + begin + Self.ResizeData(2); + pWord(@PaletteValues[0])^ := ByteSwap16(GetRValue(Value)); + end; + COLOR_RGB: + begin + Self.ResizeData(6); + pWord(@PaletteValues[0])^ := ByteSwap16(GetRValue(Value)); + pWord(@PaletteValues[2])^ := ByteSwap16(GetGValue(Value)); + pWord(@PaletteValues[4])^ := ByteSwap16(GetBValue(Value)); + end; + COLOR_PALETTE: + begin + {Creates a RGBQuad to search for the color} + LookColor.rgbRed := GetRValue(Value); + LookColor.rgbGreen := GetGValue(Value); + LookColor.rgbBlue := GetBValue(Value); + {Look in the table for the entry} + for i := 0 to 255 do + if CompareMem(@BitmapInfo.bmiColors[i], @LookColor, 3) then + Break; + {Fill the transparency table} + Fillchar(PaletteValues, i, 255); + Self.ResizeData(i + 1) + + end + end {case / with}; + +end; + +{Returns the transparent color for the image} +function TChunktRNS.GetTransparentColor: ColorRef; +var + PaletteChunk: TChunkPLTE; + i: Integer; +begin + Result := 0; {Default: Unknown transparent color} + + {Depends on the color type} + with Header do + case ColorType of + COLOR_GRAYSCALE: + Result := RGB(PaletteValues[0], PaletteValues[0], + PaletteValues[0]); + COLOR_RGB: + Result := RGB(PaletteValues[1], PaletteValues[3], PaletteValues[5]); + COLOR_PALETTE: + begin + {Obtains the palette chunk} + PaletteChunk := Owner.Chunks.ItemFromClass(TChunkPLTE) as TChunkPLTE; + + {Looks for an entry with 0 transparency meaning that it is the} + {full transparent entry} + for i := 0 to Self.DataSize - 1 do + if PaletteValues[i] = 0 then + with PaletteChunk.GetPaletteItem(i) do + begin + Result := RGB(rgbRed, rgbGreen, rgbBlue); + break + end + end {COLOR_PALETTE} + end {case Header.ColorType}; +end; + +{Saving the chunk to a stream} +function TChunktRNS.SaveToStream(Stream: TStream): Boolean; +begin + {Copy palette into data buffer} + if DataSize <= 256 then + CopyMemory(fData, @PaletteValues[0], DataSize); + + Result := inherited SaveToStream(Stream); +end; + +{Assigns from another chunk} +procedure TChunktRNS.Assign(Source: TChunk); +begin + CopyMemory(@PaletteValues[0], @TChunkTrns(Source).PaletteValues[0], 256); + fBitTransparency := TChunkTrns(Source).fBitTransparency; + inherited Assign(Source); +end; + +{Loads the chunk from a stream} +function TChunktRNS.LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; +var + i, Differ255: Integer; +begin + {Let inherited load} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + + if not Result then Exit; + + {Make sure size is correct} + if Size > 256 then Owner.RaiseError(EPNGInvalidPalette, + EPNGInvalidPaletteText); + + {The unset items should have value 255} + Fillchar(PaletteValues[0], 256, 255); + {Copy the other values} + CopyMemory(@PaletteValues[0], fData, Size); + + {Create the mask if needed} + case Header.ColorType of + {Mask for grayscale and RGB} + COLOR_RGB, COLOR_GRAYSCALE: fBitTransparency := True; + COLOR_PALETTE: + begin + Differ255 := 0; {Count the entries with a value different from 255} + {Tests if it uses bit transparency} + for i := 0 to Size - 1 do + if PaletteValues[i] <> 255 then inc(Differ255); + + {If it has one value different from 255 it is a bit transparency} + fBitTransparency := (Differ255 = 1); + end {COLOR_PALETTE} + end {case Header.ColorType}; + +end; + +{Prepares the image palette} +procedure TChunkIDAT.PreparePalette; +var + Entries: Word; + j : Integer; +begin + {In case the image uses grayscale, build a grayscale palette} + with Header do + if (ColorType = COLOR_GRAYSCALE) or (ColorType = COLOR_GRAYSCALEALPHA) then + begin + {Calculate total number of palette entries} + Entries := (1 shl Byte(BitmapInfo.bmiHeader.biBitCount)); + + FOR j := 0 TO Entries - 1 DO + with BitmapInfo.bmiColors[j] do + begin + + {Calculate each palette entry} + rgbRed := fOwner.GammaTable[MulDiv(j, 255, Entries - 1)]; + rgbGreen := rgbRed; + rgbBlue := rgbRed; + end {with BitmapInfo.bmiColors[j]} + end {if ColorType = COLOR_GRAYSCALE..., with Header} +end; + +{Reads from ZLIB} +function TChunkIDAT.IDATZlibRead(var ZLIBStream: TZStreamRec2; + Buffer: Pointer; Count: Integer; var EndPos: Integer; + var crcfile: Cardinal): Integer; +var + ProcResult : Integer; + IDATHeader : Array[0..3] of char; + IDATCRC : Cardinal; +begin + {Uses internal record pointed by ZLIBStream to gather information} + with ZLIBStream, ZLIBStream.zlib do + begin + {Set the buffer the zlib will read into} + next_out := Buffer; + avail_out := Count; + + {Decode until it reach the Count variable} + while avail_out > 0 do + begin + {In case it needs more data and it's in the end of a IDAT chunk,} + {it means that there are more IDAT chunks} + if (fStream.Position = EndPos) and (avail_out > 0) and + (avail_in = 0) then + begin + {End this chunk by reading and testing the crc value} + fStream.Read(IDATCRC, 4); + + {$IFDEF CheckCRC} + if crcfile xor $ffffffff <> Cardinal(ByteSwap(IDATCRC)) then + begin + Result := -1; + Owner.RaiseError(EPNGInvalidCRC, EPNGInvalidCRCText); + exit; + end; + {$ENDIF} + + {Start reading the next chunk} + fStream.Read(EndPos, 4); {Reads next chunk size} + fStream.Read(IDATHeader[0], 4); {Next chunk header} + {It must be a IDAT chunk since image data is required and PNG} + {specification says that multiple IDAT chunks must be consecutive} + if IDATHeader <> 'IDAT' then + begin + Owner.RaiseError(EPNGMissingMultipleIDAT, EPNGMissingMultipleIDATText); + result := -1; + exit; + end; + + {Calculate chunk name part of the crc} + {$IFDEF CheckCRC} + crcfile := update_crc($ffffffff, @IDATHeader[0], 4); + {$ENDIF} + EndPos := fStream.Position + ByteSwap(EndPos); + end; + + + {In case it needs compressed data to read from} + if avail_in = 0 then + begin + {In case it's trying to read more than it is avaliable} + if fStream.Position + ZLIBAllocate > EndPos then + avail_in := fStream.Read(Data^, EndPos - fStream.Position) + else + avail_in := fStream.Read(Data^, ZLIBAllocate); + {Update crc} + {$IFDEF CheckCRC} + crcfile := update_crc(crcfile, Data, avail_in); + {$ENDIF} + + {In case there is no more compressed data to read from} + if avail_in = 0 then + begin + Result := Count - avail_out; + Exit; + end; + + {Set next buffer to read and record current position} + next_in := Data; + + end {if avail_in = 0}; + + ProcResult := inflate(zlib, 0); + + {In case the result was not sucessfull} + if (ProcResult < 0) then + begin + Result := -1; + Owner.RaiseError(EPNGZLIBError, + EPNGZLIBErrorText + zliberrors[procresult]); + exit; + end; + + end {while avail_out > 0}; + + end {with}; + + {If everything gone ok, it returns the count bytes} + Result := Count; +end; + +{TChunkIDAT implementation} + +const + {Adam 7 interlacing values} + RowStart: array[0..6] of Integer = (0, 0, 4, 0, 2, 0, 1); + ColumnStart: array[0..6] of Integer = (0, 4, 0, 2, 0, 1, 0); + RowIncrement: array[0..6] of Integer = (8, 8, 8, 4, 4, 2, 2); + ColumnIncrement: array[0..6] of Integer = (8, 8, 4, 4, 2, 2, 1); + +{Copy interlaced images with 1 byte for R, G, B} +procedure TChunkIDAT.CopyInterlacedRGB8(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col * 3); + repeat + {Copy this row} + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + + {Move to next column} + inc(Src, 3); + inc(Dest, ColumnIncrement[Pass] * 3 - 3); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy interlaced images with 2 bytes for R, G, B} +procedure TChunkIDAT.CopyInterlacedRGB16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col * 3); + repeat + {Copy this row} + Byte(Dest^) := Owner.GammaTable[pByte(Longint(Src) + 4)^]; inc(Dest); + Byte(Dest^) := Owner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := Owner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + {$IFDEF Store16bits} + {Copy extra pixel values} + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 5)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 3)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Extra); + {$ENDIF} + + {Move to next column} + inc(Src, 6); + inc(Dest, ColumnIncrement[Pass] * 3 - 3); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy ímages with palette using bit depths 1, 4 or 8} +procedure TChunkIDAT.CopyInterlacedPalette148(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +const + BitTable: Array[1..8] of Integer = ($1, $3, 0, $F, 0, 0, 0, $FF); + StartBit: Array[1..8] of Integer = (7 , 0 , 0, 4, 0, 0, 0, 0); +var + CurBit, Col: Integer; + Dest2: PChar; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + repeat + {Copy data} + CurBit := StartBit[Header.BitDepth]; + repeat + {Adjust pointer to pixel byte bounds} + Dest2 := pChar(Longint(Dest) + (Header.BitDepth * Col) div 8); + {Copy data} + Byte(Dest2^) := Byte(Dest2^) or + ( ((Byte(Src^) shr CurBit) and BitTable[Header.BitDepth]) + shl (StartBit[Header.BitDepth] - (Col * Header.BitDepth mod 8))); + + {Move to next column} + inc(Col, ColumnIncrement[Pass]); + {Will read next bits} + dec(CurBit, Header.BitDepth); + until CurBit < 0; + + {Move to next byte in source} + inc(Src); + until Col >= ImageWidth; +end; + +{Copy ímages with palette using bit depth 2} +procedure TChunkIDAT.CopyInterlacedPalette2(const Pass: Byte; Src, Dest, + Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + CurBit, Col: Integer; + Dest2: PChar; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + repeat + {Copy data} + CurBit := 6; + repeat + {Adjust pointer to pixel byte bounds} + Dest2 := pChar(Longint(Dest) + Col div 2); + {Copy data} + Byte(Dest2^) := Byte(Dest2^) or (((Byte(Src^) shr CurBit) and $3) + shl (4 - (4 * Col) mod 8)); + {Move to next column} + inc(Col, ColumnIncrement[Pass]); + {Will read next bits} + dec(CurBit, 2); + until CurBit < 0; + + {Move to next byte in source} + inc(Src); + until Col >= ImageWidth; +end; + +{Copy ímages with grayscale using bit depth 2} +procedure TChunkIDAT.CopyInterlacedGray2(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + CurBit, Col: Integer; + Dest2: PChar; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + repeat + {Copy data} + CurBit := 6; + repeat + {Adjust pointer to pixel byte bounds} + Dest2 := pChar(Longint(Dest) + Col div 2); + {Copy data} + Byte(Dest2^) := Byte(Dest2^) or ((((Byte(Src^) shr CurBit) shl 2) and $F) + shl (4 - (Col*4) mod 8)); + {Move to next column} + inc(Col, ColumnIncrement[Pass]); + {Will read next bits} + dec(CurBit, 2); + until CurBit < 0; + + {Move to next byte in source} + inc(Src); + until Col >= ImageWidth; +end; + +{Copy ímages with palette using 2 bytes for each pixel} +procedure TChunkIDAT.CopyInterlacedGrayscale16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col); + repeat + {Copy this row} + Dest^ := Src^; inc(Dest); + {$IFDEF Store16bits} + Extra^ := pChar(Longint(Src) + 1)^; inc(Extra); + {$ENDIF} + + {Move to next column} + inc(Src, 2); + inc(Dest, ColumnIncrement[Pass] - 1); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Decodes interlaced RGB alpha with 1 byte for each sample} +procedure TChunkIDAT.CopyInterlacedRGBAlpha8(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col * 3); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this row and alpha value} + Trans^ := pChar(Longint(Src) + 3)^; + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + + {Move to next column} + inc(Src, 4); + inc(Dest, ColumnIncrement[Pass] * 3 - 3); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Decodes interlaced RGB alpha with 2 bytes for each sample} +procedure TChunkIDAT.CopyInterlacedRGBAlpha16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col * 3); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this row and alpha value} + Trans^ := pChar(Longint(Src) + 6)^; + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 4)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + {$IFDEF Store16bits} + {Copy extra pixel values} + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 5)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 3)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Extra); + {$ENDIF} + + {Move to next column} + inc(Src, 8); + inc(Dest, ColumnIncrement[Pass] * 3 - 3); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Decodes 8 bit grayscale image followed by an alpha sample} +procedure TChunkIDAT.CopyInterlacedGrayscaleAlpha8(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column, pointers to the data and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this grayscale value and alpha} + Dest^ := Src^; inc(Src); + Trans^ := Src^; inc(Src); + + {Move to next column} + inc(Dest, ColumnIncrement[Pass]); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Decodes 16 bit grayscale image followed by an alpha sample} +procedure TChunkIDAT.CopyInterlacedGrayscaleAlpha16(const Pass: Byte; + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + Col: Integer; +begin + {Get first column, pointers to the data and enter in loop} + Col := ColumnStart[Pass]; + Dest := pChar(Longint(Dest) + Col); + Trans := pChar(Longint(Trans) + Col); + repeat + {$IFDEF Store16bits} + Extra^ := pChar(Longint(Src) + 1)^; inc(Extra); + {$ENDIF} + {Copy this grayscale value and alpha, transforming 16 bits into 8} + Dest^ := Src^; inc(Src, 2); + Trans^ := Src^; inc(Src, 2); + + {Move to next column} + inc(Dest, ColumnIncrement[Pass]); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Decodes an interlaced image} +procedure TChunkIDAT.DecodeInterlacedAdam7(Stream: TStream; + var ZLIBStream: TZStreamRec2; const Size: Integer; var crcfile: Cardinal); +var + CurrentPass: Byte; + PixelsThisRow: Integer; + CurrentRow: Integer; + Trans, Data{$IFDEF Store16bits}, Extra{$ENDIF}: pChar; + CopyProc: procedure(const Pass: Byte; Src, Dest, + Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar) of object; +begin + + CopyProc := nil; {Initialize} + {Determine method to copy the image data} + case Header.ColorType of + {R, G, B values for each pixel} + COLOR_RGB: + case Header.BitDepth of + 8: CopyProc := CopyInterlacedRGB8; + 16: CopyProc := CopyInterlacedRGB16; + end {case Header.BitDepth}; + {Palette} + COLOR_PALETTE, COLOR_GRAYSCALE: + case Header.BitDepth of + 1, 4, 8: CopyProc := CopyInterlacedPalette148; + 2 : if Header.ColorType = COLOR_PALETTE then + CopyProc := CopyInterlacedPalette2 + else + CopyProc := CopyInterlacedGray2; + 16 : CopyProc := CopyInterlacedGrayscale16; + end; + {RGB followed by alpha} + COLOR_RGBALPHA: + case Header.BitDepth of + 8: CopyProc := CopyInterlacedRGBAlpha8; + 16: CopyProc := CopyInterlacedRGBAlpha16; + end; + {Grayscale followed by alpha} + COLOR_GRAYSCALEALPHA: + case Header.BitDepth of + 8: CopyProc := CopyInterlacedGrayscaleAlpha8; + 16: CopyProc := CopyInterlacedGrayscaleAlpha16; + end; + end {case Header.ColorType}; + + {Adam7 method has 7 passes to make the final image} + FOR CurrentPass := 0 TO 6 DO + begin + {Calculates the number of pixels and bytes for this pass row} + PixelsThisRow := (ImageWidth - ColumnStart[CurrentPass] + + ColumnIncrement[CurrentPass] - 1) div ColumnIncrement[CurrentPass]; + Row_Bytes := BytesForPixels(PixelsThisRow, Header.ColorType, + Header.BitDepth); + {Clear buffer for this pass} + ZeroMemory(Row_Buffer[not RowUsed], Row_Bytes); + + {Get current row index} + CurrentRow := RowStart[CurrentPass]; + {Get a pointer to the current row image data} + Data := Ptr(Longint(Header.ImageData) + Header.BytesPerRow * + (ImageHeight - 1 - CurrentRow)); + Trans := Ptr(Longint(Header.ImageAlpha) + ImageWidth * CurrentRow); + {$IFDEF Store16bits} + Extra := Ptr(Longint(Header.ExtraImageData) + Header.BytesPerRow * + (ImageHeight - 1 - CurrentRow)); + {$ENDIF} + + if Row_Bytes > 0 then {There must have bytes for this interlaced pass} + while CurrentRow < ImageHeight do + begin + {Reads this line and filter} + if IDATZlibRead(ZLIBStream, @Row_Buffer[RowUsed][0], Row_Bytes + 1, + EndPos, CRCFile) = 0 then break; + + FilterRow; + {Copy image data} + + CopyProc(CurrentPass, @Row_Buffer[RowUsed][1], Data, Trans + {$IFDEF Store16bits}, Extra{$ENDIF}); + + {Use the other RowBuffer item} + RowUsed := not RowUsed; + + {Move to the next row} + inc(CurrentRow, RowIncrement[CurrentPass]); + {Move pointer to the next line} + dec(Data, RowIncrement[CurrentPass] * Header.BytesPerRow); + inc(Trans, RowIncrement[CurrentPass] * ImageWidth); + {$IFDEF Store16bits} + dec(Extra, RowIncrement[CurrentPass] * Header.BytesPerRow); + {$ENDIF} + end {while CurrentRow < ImageHeight}; + + end {FOR CurrentPass}; + +end; + +{Copy 8 bits RGB image} +procedure TChunkIDAT.CopyNonInterlacedRGB8( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + {Copy pixel values} + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + {Move to next pixel} + inc(Src, 3); + end {for I} +end; + +{Copy 16 bits RGB image} +procedure TChunkIDAT.CopyNonInterlacedRGB16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + //Since windows does not supports 2 bytes for + //each R, G, B value, the method will read only 1 byte from it + {Copy pixel values} + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 4)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + {$IFDEF Store16bits} + {Copy extra pixel values} + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 5)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 3)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Extra); + {$ENDIF} + + {Move to next pixel} + inc(Src, 6); + end {for I} +end; + +{Copy types using palettes (1, 4 or 8 bits per pixel)} +procedure TChunkIDAT.CopyNonInterlacedPalette148( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +begin + {It's simple as copying the data} + CopyMemory(Dest, Src, Row_Bytes); +end; + +{Copy grayscale types using 2 bits for each pixel} +procedure TChunkIDAT.CopyNonInterlacedGray2( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + i: Integer; +begin + {2 bits is not supported, this routine will converted into 4 bits} + FOR i := 1 TO Row_Bytes do + begin + Byte(Dest^) := ((Byte(Src^) shr 2) and $F) or ((Byte(Src^)) and $F0); inc(Dest); + Byte(Dest^) := ((Byte(Src^) shl 2) and $F) or ((Byte(Src^) shl 4) and $F0); inc(Dest); + inc(Src); + end {FOR i} +end; + +{Copy types using palette with 2 bits for each pixel} +procedure TChunkIDAT.CopyNonInterlacedPalette2( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + i: Integer; +begin + {2 bits is not supported, this routine will converted into 4 bits} + FOR i := 1 TO Row_Bytes do + begin + Byte(Dest^) := ((Byte(Src^) shr 4) and $3) or ((Byte(Src^) shr 2) and $30); inc(Dest); + Byte(Dest^) := (Byte(Src^) and $3) or ((Byte(Src^) shl 2) and $30); inc(Dest); + inc(Src); + end {FOR i} +end; + +{Copy grayscale images with 16 bits} +procedure TChunkIDAT.CopyNonInterlacedGrayscale16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + {Windows does not supports 16 bits for each pixel in grayscale} + {mode, so reduce to 8} + Dest^ := Src^; inc(Dest); + {$IFDEF Store16bits} + Extra^ := pChar(Longint(Src) + 1)^; inc(Extra); + {$ENDIF} + + {Move to next pixel} + inc(Src, 2); + end {for I} +end; + +{Copy 8 bits per sample RGB images followed by an alpha byte} +procedure TChunkIDAT.CopyNonInterlacedRGBAlpha8( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + i: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + {Copy pixel values and transparency} + Trans^ := pChar(Longint(Src) + 3)^; + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + {Move to next pixel} + inc(Src, 4); inc(Trans); + end {for I} +end; + +{Copy 16 bits RGB image with alpha using 2 bytes for each sample} +procedure TChunkIDAT.CopyNonInterlacedRGBAlpha16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + //Copy rgb and alpha values (transforming from 16 bits to 8 bits) + {Copy pixel values} + Trans^ := pChar(Longint(Src) + 6)^; + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 4)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.GammaTable[pByte(Longint(Src) )^]; inc(Dest); + {$IFDEF Store16bits} + {Copy extra pixel values} + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 5)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 3)^]; inc(Extra); + Byte(Extra^) := fOwner.GammaTable[pByte(Longint(Src) + 1)^]; inc(Extra); + {$ENDIF} + {Move to next pixel} + inc(Src, 8); inc(Trans); + end {for I} +end; + +{Copy 8 bits per sample grayscale followed by alpha} +procedure TChunkIDAT.CopyNonInterlacedGrayscaleAlpha8( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + {Copy alpha value and then gray value} + Dest^ := Src^; inc(Src); + Trans^ := Src^; inc(Src); + inc(Dest); inc(Trans); + end; +end; + +{Copy 16 bits per sample grayscale followed by alpha} +procedure TChunkIDAT.CopyNonInterlacedGrayscaleAlpha16( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + {Copy alpha value and then gray value} + {$IFDEF Store16bits} + Extra^ := pChar(Longint(Src) + 1)^; inc(Extra); + {$ENDIF} + Dest^ := Src^; inc(Src, 2); + Trans^ := Src^; inc(Src, 2); + inc(Dest); inc(Trans); + end; +end; + +{Decode non interlaced image} +procedure TChunkIDAT.DecodeNonInterlaced(Stream: TStream; + var ZLIBStream: TZStreamRec2; const Size: Integer; var crcfile: Cardinal); +var + j: Cardinal; + Trans, Data{$IFDEF Store16bits}, Extra{$ENDIF}: pChar; + CopyProc: procedure( + Src, Dest, Trans{$IFDEF Store16bits}, Extra{$ENDIF}: pChar) of object; +begin + CopyProc := nil; {Initialize} + {Determines the method to copy the image data} + case Header.ColorType of + {R, G, B values} + COLOR_RGB: + case Header.BitDepth of + 8: CopyProc := CopyNonInterlacedRGB8; + 16: CopyProc := CopyNonInterlacedRGB16; + end; + {Types using palettes} + COLOR_PALETTE, COLOR_GRAYSCALE: + case Header.BitDepth of + 1, 4, 8: CopyProc := CopyNonInterlacedPalette148; + 2 : if Header.ColorType = COLOR_PALETTE then + CopyProc := CopyNonInterlacedPalette2 + else + CopyProc := CopyNonInterlacedGray2; + 16 : CopyProc := CopyNonInterlacedGrayscale16; + end; + {R, G, B followed by alpha} + COLOR_RGBALPHA: + case Header.BitDepth of + 8 : CopyProc := CopyNonInterlacedRGBAlpha8; + 16 : CopyProc := CopyNonInterlacedRGBAlpha16; + end; + {Grayscale followed by alpha} + COLOR_GRAYSCALEALPHA: + case Header.BitDepth of + 8 : CopyProc := CopyNonInterlacedGrayscaleAlpha8; + 16 : CopyProc := CopyNonInterlacedGrayscaleAlpha16; + end; + end; + + {Get the image data pointer} + Longint(Data) := Longint(Header.ImageData) + + Header.BytesPerRow * (ImageHeight - 1); + Trans := Header.ImageAlpha; + {$IFDEF Store16bits} + Longint(Extra) := Longint(Header.ExtraImageData) + + Header.BytesPerRow * (ImageHeight - 1); + {$ENDIF} + {Reads each line} + FOR j := 0 to ImageHeight - 1 do + begin + {Read this line Row_Buffer[RowUsed][0] if the filter type for this line} + if IDATZlibRead(ZLIBStream, @Row_Buffer[RowUsed][0], Row_Bytes + 1, EndPos, + CRCFile) = 0 then break; + + {Filter the current row} + FilterRow; + {Copies non interlaced row to image} + CopyProc(@Row_Buffer[RowUsed][1], Data, Trans{$IFDEF Store16bits}, Extra + {$ENDIF}); + + {Invert line used} + RowUsed := not RowUsed; + dec(Data, Header.BytesPerRow); + {$IFDEF Store16bits}dec(Extra, Header.BytesPerRow);{$ENDIF} + inc(Trans, ImageWidth); + end {for I}; + + +end; + +{Filter the current line} +procedure TChunkIDAT.FilterRow; +var + pp: Byte; + vv, left, above, aboveleft: Integer; + Col: Cardinal; +begin + {Test the filter} + case Row_Buffer[RowUsed]^[0] of + {No filtering for this line} + FILTER_NONE: begin end; + {AND 255 serves only to never let the result be larger than one byte} + {Sub filter} + FILTER_SUB: + FOR Col := Offset + 1 to Row_Bytes DO + Row_Buffer[RowUsed][Col] := (Row_Buffer[RowUsed][Col] + + Row_Buffer[RowUsed][Col - Offset]) and 255; + {Up filter} + FILTER_UP: + FOR Col := 1 to Row_Bytes DO + Row_Buffer[RowUsed][Col] := (Row_Buffer[RowUsed][Col] + + Row_Buffer[not RowUsed][Col]) and 255; + {Average filter} + FILTER_AVERAGE: + FOR Col := 1 to Row_Bytes DO + begin + {Obtains up and left pixels} + above := Row_Buffer[not RowUsed][Col]; + if col - 1 < Offset then + left := 0 + else + Left := Row_Buffer[RowUsed][Col - Offset]; + + {Calculates} + Row_Buffer[RowUsed][Col] := (Row_Buffer[RowUsed][Col] + + (left + above) div 2) and 255; + end; + {Paeth filter} + FILTER_PAETH: + begin + {Initialize} + left := 0; + aboveleft := 0; + {Test each byte} + FOR Col := 1 to Row_Bytes DO + begin + {Obtains above pixel} + above := Row_Buffer[not RowUsed][Col]; + {Obtains left and top-left pixels} + if (col - 1 >= offset) Then + begin + left := row_buffer[RowUsed][col - offset]; + aboveleft := row_buffer[not RowUsed][col - offset]; + end; + + {Obtains current pixel and paeth predictor} + vv := row_buffer[RowUsed][Col]; + pp := PaethPredictor(left, above, aboveleft); + + {Calculates} + Row_Buffer[RowUsed][Col] := (pp + vv) and $FF; + end {for}; + end; + + end {case}; +end; + +{Reads the image data from the stream} +function TChunkIDAT.LoadFromStream(Stream: TStream; const ChunkName: TChunkName; + Size: Integer): Boolean; +var + ZLIBStream: TZStreamRec2; + CRCCheck, + CRCFile : Cardinal; +begin + {Get pointer to the header chunk} + Header := Owner.Chunks.Item[0] as TChunkIHDR; + {Build palette if necessary} + if Header.HasPalette then PreparePalette(); + + {Copy image width and height} + ImageWidth := Header.Width; + ImageHeight := Header.Height; + + {Initialize to calculate CRC} + {$IFDEF CheckCRC} + CRCFile := update_crc($ffffffff, @ChunkName[0], 4); + {$ENDIF} + + Owner.GetPixelInfo(Row_Bytes, Offset); {Obtain line information} + ZLIBStream := ZLIBInitInflate(Stream); {Initializes decompression} + + {Calculate ending position for the current IDAT chunk} + EndPos := Stream.Position + Size; + + {Allocate memory} + GetMem(Row_Buffer[false], Row_Bytes + 1); + GetMem(Row_Buffer[true], Row_Bytes + 1); + ZeroMemory(Row_Buffer[false], Row_bytes + 1); + {Set the variable to alternate the Row_Buffer item to use} + RowUsed := TRUE; + + {Call special methods for the different interlace methods} + case Owner.InterlaceMethod of + imNone: DecodeNonInterlaced(stream, ZLIBStream, Size, crcfile); + imAdam7: DecodeInterlacedAdam7(stream, ZLIBStream, size, crcfile); + end; + + {Free memory} + ZLIBTerminateInflate(ZLIBStream); {Terminates decompression} + FreeMem(Row_Buffer[False], Row_Bytes + 1); + FreeMem(Row_Buffer[True], Row_Bytes + 1); + + {Now checks CRC} + Stream.Read(CRCCheck, 4); + {$IFDEF CheckCRC} + CRCFile := CRCFile xor $ffffffff; + CRCCheck := ByteSwap(CRCCheck); + Result := CRCCheck = CRCFile; + + {Handle CRC error} + if not Result then + begin + {In case it coult not load chunk} + Owner.RaiseError(EPngInvalidCRC, EPngInvalidCRCText); + exit; + end; + {$ELSE}Result := TRUE; {$ENDIF} +end; + +const + IDATHeader: Array[0..3] of char = ('I', 'D', 'A', 'T'); + BUFFER = 5; + +{Saves the IDAT chunk to a stream} +function TChunkIDAT.SaveToStream(Stream: TStream): Boolean; +var + ZLIBStream : TZStreamRec2; +begin + {Get pointer to the header chunk} + Header := Owner.Chunks.Item[0] as TChunkIHDR; + {Copy image width and height} + ImageWidth := Header.Width; + ImageHeight := Header.Height; + Owner.GetPixelInfo(Row_Bytes, Offset); {Obtain line information} + + {Allocate memory} + GetMem(Encode_Buffer[BUFFER], Row_Bytes); + ZeroMemory(Encode_Buffer[BUFFER], Row_Bytes); + {Allocate buffers for the filters selected} + {Filter none will always be calculated to the other filters to work} + GetMem(Encode_Buffer[FILTER_NONE], Row_Bytes); + ZeroMemory(Encode_Buffer[FILTER_NONE], Row_Bytes); + if pfSub in Owner.Filters then + GetMem(Encode_Buffer[FILTER_SUB], Row_Bytes); + if pfUp in Owner.Filters then + GetMem(Encode_Buffer[FILTER_UP], Row_Bytes); + if pfAverage in Owner.Filters then + GetMem(Encode_Buffer[FILTER_AVERAGE], Row_Bytes); + if pfPaeth in Owner.Filters then + GetMem(Encode_Buffer[FILTER_PAETH], Row_Bytes); + + {Initialize ZLIB} + ZLIBStream := ZLIBInitDeflate(Stream, Owner.fCompressionLevel, + Owner.MaxIdatSize); + {Write data depending on the interlace method} + case Owner.InterlaceMethod of + imNone: EncodeNonInterlaced(stream, ZLIBStream); + imAdam7: EncodeInterlacedAdam7(stream, ZLIBStream); + end; + {Terminates ZLIB} + ZLIBTerminateDeflate(ZLIBStream); + + {Release allocated memory} + FreeMem(Encode_Buffer[BUFFER], Row_Bytes); + FreeMem(Encode_Buffer[FILTER_NONE], Row_Bytes); + if pfSub in Owner.Filters then + FreeMem(Encode_Buffer[FILTER_SUB], Row_Bytes); + if pfUp in Owner.Filters then + FreeMem(Encode_Buffer[FILTER_UP], Row_Bytes); + if pfAverage in Owner.Filters then + FreeMem(Encode_Buffer[FILTER_AVERAGE], Row_Bytes); + if pfPaeth in Owner.Filters then + FreeMem(Encode_Buffer[FILTER_PAETH], Row_Bytes); + + {Everything went ok} + Result := True; +end; + +{Writes the IDAT using the settings} +procedure WriteIDAT(Stream: TStream; Data: Pointer; const Length: Cardinal); +var + ChunkLen, CRC: Cardinal; +begin + {Writes IDAT header} + ChunkLen := ByteSwap(Length); + Stream.Write(ChunkLen, 4); {Chunk length} + Stream.Write(IDATHeader[0], 4); {Idat header} + CRC := update_crc($ffffffff, @IDATHeader[0], 4); {Crc part for header} + + {Writes IDAT data and calculates CRC for data} + Stream.Write(Data^, Length); + CRC := Byteswap(update_crc(CRC, Data, Length) xor $ffffffff); + {Writes final CRC} + Stream.Write(CRC, 4); +end; + +{Compress and writes IDAT chunk data} +procedure TChunkIDAT.IDATZlibWrite(var ZLIBStream: TZStreamRec2; + Buffer: Pointer; const Length: Cardinal); +begin + with ZLIBStream, ZLIBStream.ZLIB do + begin + {Set data to be compressed} + next_in := Buffer; + avail_in := Length; + + {Compress all the data avaliable to compress} + while avail_in > 0 do + begin + deflate(ZLIB, Z_NO_FLUSH); + + {The whole buffer was used, save data to stream and restore buffer} + if avail_out = 0 then + begin + {Writes this IDAT chunk} + WriteIDAT(fStream, Data, ZLIBAllocate); + + {Restore buffer} + next_out := Data; + avail_out := ZLIBAllocate; + end {if avail_out = 0}; + + end {while avail_in}; + + end {with ZLIBStream, ZLIBStream.ZLIB} +end; + +{Finishes compressing data to write IDAT chunk} +procedure TChunkIDAT.FinishIDATZlib(var ZLIBStream: TZStreamRec2); +begin + with ZLIBStream, ZLIBStream.ZLIB do + begin + {Set data to be compressed} + next_in := nil; + avail_in := 0; + + while deflate(ZLIB,Z_FINISH) <> Z_STREAM_END do + begin + {Writes this IDAT chunk} + WriteIDAT(fStream, Data, ZLIBAllocate - avail_out); + {Re-update buffer} + next_out := Data; + avail_out := ZLIBAllocate; + end; + + if avail_out < ZLIBAllocate then + {Writes final IDAT} + WriteIDAT(fStream, Data, ZLIBAllocate - avail_out); + + end {with ZLIBStream, ZLIBStream.ZLIB}; +end; + +{Copy memory to encode RGB image with 1 byte for each color sample} +procedure TChunkIDAT.EncodeNonInterlacedRGB8(Src, Dest, Trans: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + {Copy pixel values} + Byte(Dest^) := fOwner.InverseGamma[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.InverseGamma[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := fOwner.InverseGamma[pByte(Longint(Src) )^]; inc(Dest); + {Move to next pixel} + inc(Src, 3); + end {for I} +end; + +{Copy memory to encode RGB images with 16 bits for each color sample} +procedure TChunkIDAT.EncodeNonInterlacedRGB16(Src, Dest, Trans: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + //Now we copy from 1 byte for each sample stored to a 2 bytes (or 1 word) + //for sample + {Copy pixel values} + pWORD(Dest)^ := fOwner.InverseGamma[pByte(Longint(Src) + 2)^]; inc(Dest, 2); + pWORD(Dest)^ := fOwner.InverseGamma[pByte(Longint(Src) + 1)^]; inc(Dest, 2); + pWORD(Dest)^ := fOwner.InverseGamma[pByte(Longint(Src) )^]; inc(Dest, 2); + {Move to next pixel} + inc(Src, 3); + end {for I} + +end; + +{Copy memory to encode types using palettes (1, 4 or 8 bits per pixel)} +procedure TChunkIDAT.EncodeNonInterlacedPalette148(Src, Dest, Trans: pChar); +begin + {It's simple as copying the data} + CopyMemory(Dest, Src, Row_Bytes); +end; + +{Copy memory to encode grayscale images with 2 bytes for each sample} +procedure TChunkIDAT.EncodeNonInterlacedGrayscale16(Src, Dest, Trans: pChar); +var + I: Integer; +begin + FOR I := 1 TO ImageWidth DO + begin + //Now we copy from 1 byte for each sample stored to a 2 bytes (or 1 word) + //for sample + pWORD(Dest)^ := pByte(Longint(Src))^; inc(Dest, 2); + {Move to next pixel} + inc(Src); + end {for I} +end; + +{Encode images using RGB followed by an alpha value using 1 byte for each} +procedure TChunkIDAT.EncodeNonInterlacedRGBAlpha8(Src, Dest, Trans: pChar); +var + i: Integer; +begin + {Copy the data to the destination, including data from Trans pointer} + FOR i := 1 TO ImageWidth do + begin + Byte(Dest^) := Owner.InverseGamma[PByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := Owner.InverseGamma[PByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := Owner.InverseGamma[PByte(Longint(Src) )^]; inc(Dest); + Dest^ := Trans^; inc(Dest); + inc(Src, 3); inc(Trans); + end {for i}; +end; + +{Encode images using RGB followed by an alpha value using 2 byte for each} +procedure TChunkIDAT.EncodeNonInterlacedRGBAlpha16(Src, Dest, Trans: pChar); +var + i: Integer; +begin + {Copy the data to the destination, including data from Trans pointer} + FOR i := 1 TO ImageWidth do + begin + pWord(Dest)^ := Owner.InverseGamma[PByte(Longint(Src) + 2)^]; inc(Dest, 2); + pWord(Dest)^ := Owner.InverseGamma[PByte(Longint(Src) + 1)^]; inc(Dest, 2); + pWord(Dest)^ := Owner.InverseGamma[PByte(Longint(Src) )^]; inc(Dest, 2); + pWord(Dest)^ := PByte(Longint(Trans) )^; inc(Dest, 2); + inc(Src, 3); inc(Trans); + end {for i}; +end; + +{Encode grayscale images followed by an alpha value using 1 byte for each} +procedure TChunkIDAT.EncodeNonInterlacedGrayscaleAlpha8( + Src, Dest, Trans: pChar); +var + i: Integer; +begin + {Copy the data to the destination, including data from Trans pointer} + FOR i := 1 TO ImageWidth do + begin + Dest^ := Src^; inc(Dest); + Dest^ := Trans^; inc(Dest); + inc(Src); inc(Trans); + end {for i}; +end; + +{Encode grayscale images followed by an alpha value using 2 byte for each} +procedure TChunkIDAT.EncodeNonInterlacedGrayscaleAlpha16( + Src, Dest, Trans: pChar); +var + i: Integer; +begin + {Copy the data to the destination, including data from Trans pointer} + FOR i := 1 TO ImageWidth do + begin + pWord(Dest)^ := pByte(Src)^; inc(Dest, 2); + pWord(Dest)^ := pByte(Trans)^; inc(Dest, 2); + inc(Src); inc(Trans); + end {for i}; +end; + +{Encode non interlaced images} +procedure TChunkIDAT.EncodeNonInterlaced(Stream: TStream; + var ZLIBStream: TZStreamRec2); +var + {Current line} + j: Cardinal; + {Pointers to image data} + Data, Trans: PChar; + {Filter used for this line} + Filter: Byte; + {Method which will copy the data into the buffer} + CopyProc: procedure(Src, Dest, Trans: pChar) of object; +begin + CopyProc := nil; {Initialize to avoid warnings} + {Defines the method to copy the data to the buffer depending on} + {the image parameters} + case Header.ColorType of + {R, G, B values} + COLOR_RGB: + case Header.BitDepth of + 8: CopyProc := EncodeNonInterlacedRGB8; + 16: CopyProc := EncodeNonInterlacedRGB16; + end; + {Palette and grayscale values} + COLOR_GRAYSCALE, COLOR_PALETTE: + case Header.BitDepth of + 1, 4, 8: CopyProc := EncodeNonInterlacedPalette148; + 16: CopyProc := EncodeNonInterlacedGrayscale16; + end; + {RGB with a following alpha value} + COLOR_RGBALPHA: + case Header.BitDepth of + 8: CopyProc := EncodeNonInterlacedRGBAlpha8; + 16: CopyProc := EncodeNonInterlacedRGBAlpha16; + end; + {Grayscale images followed by an alpha} + COLOR_GRAYSCALEALPHA: + case Header.BitDepth of + 8: CopyProc := EncodeNonInterlacedGrayscaleAlpha8; + 16: CopyProc := EncodeNonInterlacedGrayscaleAlpha16; + end; + end {case Header.ColorType}; + + {Get the image data pointer} + Longint(Data) := Longint(Header.ImageData) + + Header.BytesPerRow * (ImageHeight - 1); + Trans := Header.ImageAlpha; + + {Writes each line} + FOR j := 0 to ImageHeight - 1 do + begin + {Copy data into buffer} + CopyProc(Data, @Encode_Buffer[BUFFER][0], Trans); + {Filter data} + Filter := FilterToEncode; + + {Compress data} + IDATZlibWrite(ZLIBStream, @Filter, 1); + IDATZlibWrite(ZLIBStream, @Encode_Buffer[Filter][0], Row_Bytes); + + {Adjust pointers to the actual image data} + dec(Data, Header.BytesPerRow); + inc(Trans, ImageWidth); + end; + + {Compress and finishes copying the remaining data} + FinishIDATZlib(ZLIBStream); +end; + +{Copy memory to encode interlaced images using RGB value with 1 byte for} +{each color sample} +procedure TChunkIDAT.EncodeInterlacedRGB8(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col * 3); + repeat + {Copy this row} + Byte(Dest^) := fOwner.InverseGamma[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := fOwner.InverseGamma[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := fOwner.InverseGamma[pByte(Longint(Src) )^]; inc(Dest); + + {Move to next column} + inc(Src, ColumnIncrement[Pass] * 3); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy memory to encode interlaced RGB images with 2 bytes each color sample} +procedure TChunkIDAT.EncodeInterlacedRGB16(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col * 3); + repeat + {Copy this row} + pWord(Dest)^ := Owner.InverseGamma[pByte(Longint(Src) + 2)^]; inc(Dest, 2); + pWord(Dest)^ := Owner.InverseGamma[pByte(Longint(Src) + 1)^]; inc(Dest, 2); + pWord(Dest)^ := Owner.InverseGamma[pByte(Longint(Src) )^]; inc(Dest, 2); + + {Move to next column} + inc(Src, ColumnIncrement[Pass] * 3); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy memory to encode interlaced images using palettes using bit depths} +{1, 4, 8 (each pixel in the image)} +procedure TChunkIDAT.EncodeInterlacedPalette148(const Pass: Byte; + Src, Dest, Trans: pChar); +const + BitTable: Array[1..8] of Integer = ($1, $3, 0, $F, 0, 0, 0, $FF); + StartBit: Array[1..8] of Integer = (7 , 0 , 0, 4, 0, 0, 0, 0); +var + CurBit, Col: Integer; + Src2: PChar; +begin + {Clean the line} + fillchar(Dest^, Row_Bytes, #0); + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + with Header.BitmapInfo.bmiHeader do + repeat + {Copy data} + CurBit := StartBit[biBitCount]; + repeat + {Adjust pointer to pixel byte bounds} + Src2 := pChar(Longint(Src) + (biBitCount * Col) div 8); + {Copy data} + Byte(Dest^) := Byte(Dest^) or + (((Byte(Src2^) shr (StartBit[Header.BitDepth] - (biBitCount * Col) + mod 8))) and (BitTable[biBitCount])) shl CurBit; + + {Move to next column} + inc(Col, ColumnIncrement[Pass]); + {Will read next bits} + dec(CurBit, biBitCount); + until CurBit < 0; + + {Move to next byte in source} + inc(Dest); + until Col >= ImageWidth; +end; + +{Copy to encode interlaced grayscale images using 16 bits for each sample} +procedure TChunkIDAT.EncodeInterlacedGrayscale16(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col); + repeat + {Copy this row} + pWord(Dest)^ := Byte(Src^); inc(Dest, 2); + + {Move to next column} + inc(Src, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy to encode interlaced rgb images followed by an alpha value, all using} +{one byte for each sample} +procedure TChunkIDAT.EncodeInterlacedRGBAlpha8(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col * 3); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this row} + Byte(Dest^) := Owner.InverseGamma[pByte(Longint(Src) + 2)^]; inc(Dest); + Byte(Dest^) := Owner.InverseGamma[pByte(Longint(Src) + 1)^]; inc(Dest); + Byte(Dest^) := Owner.InverseGamma[pByte(Longint(Src) )^]; inc(Dest); + Dest^ := Trans^; inc(Dest); + + {Move to next column} + inc(Src, ColumnIncrement[Pass] * 3); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy to encode interlaced rgb images followed by an alpha value, all using} +{two byte for each sample} +procedure TChunkIDAT.EncodeInterlacedRGBAlpha16(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col * 3); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this row} + pWord(Dest)^ := pByte(Longint(Src) + 2)^; inc(Dest, 2); + pWord(Dest)^ := pByte(Longint(Src) + 1)^; inc(Dest, 2); + pWord(Dest)^ := pByte(Longint(Src) )^; inc(Dest, 2); + pWord(Dest)^ := pByte(Trans)^; inc(Dest, 2); + + {Move to next column} + inc(Src, ColumnIncrement[Pass] * 3); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy to encode grayscale interlaced images followed by an alpha value, all} +{using 1 byte for each sample} +procedure TChunkIDAT.EncodeInterlacedGrayscaleAlpha8(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this row} + Dest^ := Src^; inc(Dest); + Dest^ := Trans^; inc(Dest); + + {Move to next column} + inc(Src, ColumnIncrement[Pass]); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Copy to encode grayscale interlaced images followed by an alpha value, all} +{using 2 bytes for each sample} +procedure TChunkIDAT.EncodeInterlacedGrayscaleAlpha16(const Pass: Byte; + Src, Dest, Trans: pChar); +var + Col: Integer; +begin + {Get first column and enter in loop} + Col := ColumnStart[Pass]; + Src := pChar(Longint(Src) + Col); + Trans := pChar(Longint(Trans) + Col); + repeat + {Copy this row} + pWord(Dest)^ := pByte(Src)^; inc(Dest, 2); + pWord(Dest)^ := pByte(Trans)^; inc(Dest, 2); + + {Move to next column} + inc(Src, ColumnIncrement[Pass]); + inc(Trans, ColumnIncrement[Pass]); + inc(Col, ColumnIncrement[Pass]); + until Col >= ImageWidth; +end; + +{Encode interlaced images} +procedure TChunkIDAT.EncodeInterlacedAdam7(Stream: TStream; + var ZLIBStream: TZStreamRec2); +var + CurrentPass, Filter: Byte; + PixelsThisRow: Integer; + CurrentRow : Integer; + Trans, Data: pChar; + CopyProc: procedure(const Pass: Byte; + Src, Dest, Trans: pChar) of object; +begin + CopyProc := nil; {Initialize to avoid warnings} + {Defines the method to copy the data to the buffer depending on} + {the image parameters} + case Header.ColorType of + {R, G, B values} + COLOR_RGB: + case Header.BitDepth of + 8: CopyProc := EncodeInterlacedRGB8; + 16: CopyProc := EncodeInterlacedRGB16; + end; + {Grayscale and palette} + COLOR_PALETTE, COLOR_GRAYSCALE: + case Header.BitDepth of + 1, 4, 8: CopyProc := EncodeInterlacedPalette148; + 16: CopyProc := EncodeInterlacedGrayscale16; + end; + {RGB followed by alpha} + COLOR_RGBALPHA: + case Header.BitDepth of + 8: CopyProc := EncodeInterlacedRGBAlpha8; + 16: CopyProc := EncodeInterlacedRGBAlpha16; + end; + COLOR_GRAYSCALEALPHA: + {Grayscale followed by alpha} + case Header.BitDepth of + 8: CopyProc := EncodeInterlacedGrayscaleAlpha8; + 16: CopyProc := EncodeInterlacedGrayscaleAlpha16; + end; + end {case Header.ColorType}; + + {Compress the image using the seven passes for ADAM 7} + FOR CurrentPass := 0 TO 6 DO + begin + {Calculates the number of pixels and bytes for this pass row} + PixelsThisRow := (ImageWidth - ColumnStart[CurrentPass] + + ColumnIncrement[CurrentPass] - 1) div ColumnIncrement[CurrentPass]; + Row_Bytes := BytesForPixels(PixelsThisRow, Header.ColorType, + Header.BitDepth); + ZeroMemory(Encode_Buffer[FILTER_NONE], Row_Bytes); + + {Get current row index} + CurrentRow := RowStart[CurrentPass]; + {Get a pointer to the current row image data} + Data := Ptr(Longint(Header.ImageData) + Header.BytesPerRow * + (ImageHeight - 1 - CurrentRow)); + Trans := Ptr(Longint(Header.ImageAlpha) + ImageWidth * CurrentRow); + + {Process all the image rows} + if Row_Bytes > 0 then + while CurrentRow < ImageHeight do + begin + {Copy data into buffer} + CopyProc(CurrentPass, Data, @Encode_Buffer[BUFFER][0], Trans); + {Filter data} + Filter := FilterToEncode; + + {Compress data} + IDATZlibWrite(ZLIBStream, @Filter, 1); + IDATZlibWrite(ZLIBStream, @Encode_Buffer[Filter][0], Row_Bytes); + + {Move to the next row} + inc(CurrentRow, RowIncrement[CurrentPass]); + {Move pointer to the next line} + dec(Data, RowIncrement[CurrentPass] * Header.BytesPerRow); + inc(Trans, RowIncrement[CurrentPass] * ImageWidth); + end {while CurrentRow < ImageHeight} + + end {CurrentPass}; + + {Compress and finishes copying the remaining data} + FinishIDATZlib(ZLIBStream); +end; + +{Filters the row to be encoded and returns the best filter} +function TChunkIDAT.FilterToEncode: Byte; +var + Run, LongestRun, ii, jj: Cardinal; + Last, Above, LastAbove: Byte; +begin + {Selecting more filters using the Filters property from TPngObject} + {increases the chances to the file be much smaller, but decreases} + {the performace} + + {This method will creates the same line data using the different} + {filter methods and select the best} + + {Sub-filter} + if pfSub in Owner.Filters then + for ii := 0 to Row_Bytes - 1 do + begin + {There is no previous pixel when it's on the first pixel, so} + {set last as zero when in the first} + if (ii >= Offset) then + last := Encode_Buffer[BUFFER]^[ii - Offset] + else + last := 0; + Encode_Buffer[FILTER_SUB]^[ii] := Encode_Buffer[BUFFER]^[ii] - last; + end; + + {Up filter} + if pfUp in Owner.Filters then + for ii := 0 to Row_Bytes - 1 do + Encode_Buffer[FILTER_UP]^[ii] := Encode_Buffer[BUFFER]^[ii] - + Encode_Buffer[FILTER_NONE]^[ii]; + + {Average filter} + if pfAverage in Owner.Filters then + for ii := 0 to Row_Bytes - 1 do + begin + {Get the previous pixel, if the current pixel is the first, the} + {previous is considered to be 0} + if (ii >= Offset) then + last := Encode_Buffer[BUFFER]^[ii - Offset] + else + last := 0; + {Get the pixel above} + above := Encode_Buffer[FILTER_NONE]^[ii]; + + {Calculates formula to the average pixel} + Encode_Buffer[FILTER_AVERAGE]^[ii] := Encode_Buffer[BUFFER]^[ii] - + (above + last) div 2 ; + end; + + {Paeth filter (the slower)} + if pfPaeth in Owner.Filters then + begin + {Initialize} + last := 0; + lastabove := 0; + for ii := 0 to Row_Bytes - 1 do + begin + {In case this pixel is not the first in the line obtains the} + {previous one and the one above the previous} + if (ii >= Offset) then + begin + last := Encode_Buffer[BUFFER]^[ii - Offset]; + lastabove := Encode_Buffer[FILTER_NONE]^[ii - Offset]; + end; + {Obtains the pixel above} + above := Encode_Buffer[FILTER_NONE]^[ii]; + {Calculate paeth filter for this byte} + Encode_Buffer[FILTER_PAETH]^[ii] := Encode_Buffer[BUFFER]^[ii] - + PaethPredictor(last, above, lastabove); + end; + end; + + {Now calculates the same line using no filter, which is necessary} + {in order to have data to the filters when the next line comes} + CopyMemory(@Encode_Buffer[FILTER_NONE]^[0], + @Encode_Buffer[BUFFER]^[0], Row_Bytes); + + {If only filter none is selected in the filter list, we don't need} + {to proceed and further} + if (Owner.Filters = [pfNone]) or (Owner.Filters = []) then + begin + Result := FILTER_NONE; + exit; + end {if (Owner.Filters = [pfNone...}; + + {Check which filter is the best by checking which has the larger} + {sequence of the same byte, since they are best compressed} + LongestRun := 0; Result := FILTER_NONE; + for ii := FILTER_NONE TO FILTER_PAETH do + {Check if this filter was selected} + if TFilter(ii) in Owner.Filters then + begin + Run := 0; + {Check if it's the only filter} + if Owner.Filters = [TFilter(ii)] then + begin + Result := ii; + exit; + end; + + {Check using a sequence of four bytes} + for jj := 2 to Row_Bytes - 1 do + if (Encode_Buffer[ii]^[jj] = Encode_Buffer [ii]^[jj-1]) or + (Encode_Buffer[ii]^[jj] = Encode_Buffer [ii]^[jj-2]) then + inc(Run); {Count the number of sequences} + + {Check if this one is the best so far} + if (Run > LongestRun) then + begin + Result := ii; + LongestRun := Run; + end {if (Run > LongestRun)}; + + end {if TFilter(ii) in Owner.Filters}; +end; + +{TChunkPLTE implementation} + +{Returns an item in the palette} +function TChunkPLTE.GetPaletteItem(Index: Byte): TRGBQuad; +begin + {Test if item is valid, if not raise error} + if Index > Count - 1 then + Owner.RaiseError(EPNGError, EPNGUnknownPalEntryText) + else + {Returns the item} + Result := Header.BitmapInfo.bmiColors[Index]; +end; + +{Loads the palette chunk from a stream} +function TChunkPLTE.LoadFromStream(Stream: TStream; + const ChunkName: TChunkName; Size: Integer): Boolean; +type + pPalEntry = ^PalEntry; + PalEntry = record r, g, b: Byte end; +var + j : Integer; {For the FOR} + PalColor : pPalEntry; +begin + {Let ancestor load data and check CRC} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + if not Result then exit; + + {This chunk must be divisible by 3 in order to be valid} + if (Size mod 3 <> 0) or (Size div 3 > 256) then + begin + {Raise error} + Result := FALSE; + Owner.RaiseError(EPNGInvalidPalette, EPNGInvalidPaletteText); + exit; + end {if Size mod 3 <> 0}; + + {Fill array with the palette entries} + fCount := Size div 3; + PalColor := Data; + FOR j := 0 TO fCount - 1 DO + with Header.BitmapInfo.bmiColors[j] do + begin + rgbRed := Owner.GammaTable[PalColor.r]; + rgbGreen := Owner.GammaTable[PalColor.g]; + rgbBlue := Owner.GammaTable[PalColor.b]; + rgbReserved := 0; + inc(PalColor); {Move to next palette entry} + end; +end; + +{Saves the PLTE chunk to a stream} +function TChunkPLTE.SaveToStream(Stream: TStream): Boolean; +var + J: Integer; + DataPtr: pByte; +begin + {Adjust size to hold all the palette items} + ResizeData(fCount * 3); + {Copy pointer to data} + DataPtr := fData; + + {Copy palette items} + with Header do + FOR j := 0 TO fCount - 1 DO + with BitmapInfo.bmiColors[j] do + begin + DataPtr^ := Owner.InverseGamma[rgbRed]; inc(DataPtr); + DataPtr^ := Owner.InverseGamma[rgbGreen]; inc(DataPtr); + DataPtr^ := Owner.InverseGamma[rgbBlue]; inc(DataPtr); + end {with BitmapInfo}; + + {Let ancestor do the rest of the work} + Result := inherited SaveToStream(Stream); +end; + +{Assigns from another PLTE chunk} +procedure TChunkPLTE.Assign(Source: TChunk); +begin + {Copy the number of palette items} + if Source is TChunkPLTE then + fCount := TChunkPLTE(Source).fCount + else + Owner.RaiseError(EPNGError, EPNGCannotAssignChunkText); +end; + +{TChunkgAMA implementation} + +{Assigns from another chunk} +procedure TChunkgAMA.Assign(Source: TChunk); +begin + {Copy the gamma value} + if Source is TChunkgAMA then + Gamma := TChunkgAMA(Source).Gamma + else + Owner.RaiseError(EPNGError, EPNGCannotAssignChunkText); +end; + +{Gamma chunk being created} +constructor TChunkgAMA.Create(Owner: TPngObject); +begin + {Call ancestor} + inherited Create(Owner); + Gamma := 1; {Initial value} +end; + +{Returns gamma value} +function TChunkgAMA.GetValue: Cardinal; +begin + {Make sure that the size is four bytes} + if DataSize <> 4 then + begin + {Adjust size and returns 1} + ResizeData(4); + Result := 1; + end + {If it's right, read the value} + else Result := Cardinal(ByteSwap(pCardinal(Data)^)) +end; + +function Power(Base, Exponent: Extended): Extended; +begin + if Exponent = 0.0 then + Result := 1.0 {Math rule} + else if (Base = 0) or (Exponent = 0) then Result := 0 + else + Result := Exp(Exponent * Ln(Base)); +end; + + +{Loading the chunk from a stream} +function TChunkgAMA.LoadFromStream(Stream: TStream; + const ChunkName: TChunkName; Size: Integer): Boolean; +var + i: Integer; + Value: Cardinal; +begin + {Call ancestor and test if it went ok} + Result := inherited LoadFromStream(Stream, ChunkName, Size); + if not Result then exit; + Value := Gamma; + {Build gamma table and inverse table for saving} + if Value <> 0 then + with Owner do + FOR i := 0 TO 255 DO + begin + GammaTable[I] := Round(Power((I / 255), 1 / + (Value / 100000 * 2.2)) * 255); + InverseGamma[Round(Power((I / 255), 1 / + (Value / 100000 * 2.2)) * 255)] := I; + end +end; + +{Sets the gamma value} +procedure TChunkgAMA.SetValue(const Value: Cardinal); +begin + {Make sure that the size is four bytes} + if DataSize <> 4 then ResizeData(4); + {If it's right, set the value} + pCardinal(Data)^ := ByteSwap(Value); +end; + +{TPngObject implementation} + +{Assigns from another object} +procedure TPngObject.Assign(Source: TPersistent); +begin + {Assigns contents from another TPNGObject} + if Source is TPNGObject then + AssignPNG(Source as TPNGObject) + {Copy contents from a TBitmap} + {$IFDEF UseDelphi}else if Source is TBitmap then + with Source as TBitmap do + AssignHandle(Handle, Transparent, + ColorToRGB(TransparentColor)){$ENDIF} + {Unknown source, let ancestor deal with it} + else + inherited; +end; + +{Clear all the chunks in the list} +procedure TPngObject.ClearChunks; +var + i: Integer; +begin + {Initialize gamma} + InitializeGamma(); + {Free all the objects and memory (0 chunks Bug fixed by Noel Sharpe)} + for i := 0 TO Integer(Chunks.Count) - 1 do + TChunk(Chunks.Item[i]).Free; + Chunks.Count := 0; +end; + +{Portable Network Graphics object being created} +constructor TPngObject.Create; +begin + {Let it be created} + inherited Create; + + {Initial properties} + TempPalette := 0; + fFilters := [pfSub]; + fCompressionLevel := 7; + fInterlaceMethod := imNone; + fMaxIdatSize := High(Word); + {Create chunklist object} + fChunkList := TPngList.Create(Self); +end; + +{Portable Network Graphics object being destroyed} +destructor TPngObject.Destroy; +begin + {Free object list} + ClearChunks; + fChunkList.Free; + {Free the temporary palette} + if TempPalette <> 0 then DeleteObject(TempPalette); + + {Call ancestor destroy} + inherited Destroy; +end; + +{Returns linesize and byte offset for pixels} +procedure TPngObject.GetPixelInfo(var LineSize, Offset: Cardinal); +begin + {There must be an Header chunk to calculate size} + if HeaderPresent then + begin + {Calculate number of bytes for each line} + LineSize := BytesForPixels(Header.Width, Header.ColorType, Header.BitDepth); + + {Calculates byte offset} + Case Header.ColorType of + {Grayscale} + COLOR_GRAYSCALE: + If Header.BitDepth = 16 Then + Offset := 2 + Else + Offset := 1 ; + {It always smaller or equal one byte, so it occupes one byte} + COLOR_PALETTE: + offset := 1; + {It might be 3 or 6 bytes} + COLOR_RGB: + offset := 3 * Header.BitDepth Div 8; + {It might be 2 or 4 bytes} + COLOR_GRAYSCALEALPHA: + offset := 2 * Header.BitDepth Div 8; + {4 or 8 bytes} + COLOR_RGBALPHA: + offset := 4 * Header.BitDepth Div 8; + else + Offset := 0; + End ; + + end + else + begin + {In case if there isn't any Header chunk} + Offset := 0; + LineSize := 0; + end; + +end; + +{Returns image height} +function TPngObject.GetHeight: Integer; +begin + {There must be a Header chunk to get the size, otherwise returns 0} + if HeaderPresent then + Result := TChunkIHDR(Chunks.Item[0]).Height + else Result := 0; +end; + +{Returns image width} +function TPngObject.GetWidth: Integer; +begin + {There must be a Header chunk to get the size, otherwise returns 0} + if HeaderPresent then + Result := Header.Width + else Result := 0; +end; + +{Returns if the image is empty} +function TPngObject.GetEmpty: Boolean; +begin + Result := (Chunks.Count = 0); +end; + +{Raises an error} +procedure TPngObject.RaiseError(ExceptionClass: ExceptClass; Text: String); +begin + raise ExceptionClass.Create(Text); +end; + +{Set the maximum size for IDAT chunk} +procedure TPngObject.SetMaxIdatSize(const Value: Cardinal); +begin + {Make sure the size is at least 65535} + if Value < High(Word) then + fMaxIdatSize := High(Word) else fMaxIdatSize := Value; +end; + +{$IFNDEF UseDelphi} + {Creates a file stream reading from the filename in the parameter and load} + procedure TPngObject.LoadFromFile(const Filename: String); + var + FileStream: TFileStream; + begin + {Test if the file exists} + if not FileExists(Filename) then + begin + {In case it does not exists, raise error} + RaiseError(EPNGNotExists, EPNGNotExistsText); + exit; + end; + + {Creates the file stream to read} + FileStream := TFileStream.Create(Filename, [fsmRead]); + LoadFromStream(FileStream); {Loads the data} + FileStream.Free; {Free file stream} + end; + + {Saves the current png image to a file} + procedure TPngObject.SaveToFile(const Filename: String); + var + FileStream: TFileStream; + begin + {Creates the file stream to write} + FileStream := TFileStream.Create(Filename, [fsmWrite]); + SaveToStream(FileStream); {Saves the data} + FileStream.Free; {Free file stream} + end; + +{$ENDIF} + +{Returns pointer to the chunk TChunkIHDR which should be the first} +function TPngObject.GetHeader: TChunkIHDR; +begin + {If there is a TChunkIHDR returns it, otherwise returns nil} + if (Chunks.Count <> 0) and (Chunks.Item[0] is TChunkIHDR) then + Result := Chunks.Item[0] as TChunkIHDR + else + begin + {No header, throw error message} + RaiseError(EPNGHeaderNotPresent, EPNGHeaderNotPresentText); + Result := nil + end +end; + +{Draws using partial transparency} +procedure TPngObject.DrawPartialTrans(DC: HDC; Rect: TRect); +type + {Access to pixels} + TPixelLine = Array[Word] of TRGBQuad; + pPixelLine = ^TPixelLine; +const + {Structure used to create the bitmap} + BitmapInfoHeader: TBitmapInfoHeader = + (biSize: sizeof(TBitmapInfoHeader); + biWidth: 100; + biHeight: 100; + biPlanes: 1; + biBitCount: 32; + biCompression: BI_RGB; + biSizeImage: 0; + biXPelsPerMeter: 0; + biYPelsPerMeter: 0; + biClrUsed: 0; + biClrImportant: 0); +var + {Buffer bitmap creation} + BitmapInfo : TBitmapInfo; + BufferDC : HDC; + BufferBits : Pointer; + OldBitmap, + BufferBitmap: HBitmap; + + {Transparency/palette chunks} + TransparencyChunk: TChunktRNS; + PaletteChunk: TChunkPLTE; + TransValue, PaletteIndex: Byte; + CurBit: Integer; + Data: PByte; + + {Buffer bitmap modification} + BytesPerRowDest, + BytesPerRowSrc, + BytesPerRowAlpha: Integer; + ImageSource, + AlphaSource : pByteArray; + ImageData : pPixelLine; + i, j : Integer; +begin + {Prepare to create the bitmap} + Fillchar(BitmapInfo, sizeof(BitmapInfo), #0); + BitmapInfoHeader.biWidth := Header.Width; + BitmapInfoHeader.biHeight := -1 * Header.Height; + BitmapInfo.bmiHeader := BitmapInfoHeader; + + {Create the bitmap which will receive the background, the applied} + {alpha blending and then will be painted on the background} + BufferDC := CreateCompatibleDC(0); + {In case BufferDC could not be created} + if (BufferDC = 0) then RaiseError(EPNGOutMemory, EPNGOutMemoryText); + BufferBitmap := CreateDIBSection(BufferDC, BitmapInfo, DIB_RGB_COLORS, + BufferBits, 0, 0); + {In case buffer bitmap could not be created} + if (BufferBitmap = 0) or (BufferBits = Nil) then + begin + if BufferBitmap <> 0 then DeleteObject(BufferBitmap); + DeleteDC(BufferDC); + RaiseError(EPNGOutMemory, EPNGOutMemoryText); + end; + + {Selects new bitmap and release old bitmap} + OldBitmap := SelectObject(BufferDC, BufferBitmap); + + {Draws the background on the buffer image} + StretchBlt(BufferDC, 0, 0, Header.Width, Header.height, DC, Rect.Left, + Rect.Top, Header.Width, Header.Height, SRCCOPY); + + {Obtain number of bytes for each row} + BytesPerRowAlpha := Header.Width; + BytesPerRowDest := (((BitmapInfo.bmiHeader.biBitCount * Width) + 31) + and not 31) div 8; {Number of bytes for each image row in destination} + BytesPerRowSrc := (((Header.BitmapInfo.bmiHeader.biBitCount * Header.Width) + + 31) and not 31) div 8; {Number of bytes for each image row in source} + + {Obtains image pointers} + ImageData := BufferBits; + AlphaSource := Header.ImageAlpha; + Longint(ImageSource) := Longint(Header.ImageData) + + Header.BytesPerRow * Longint(Header.Height - 1); + + case Header.BitmapInfo.bmiHeader.biBitCount of + {R, G, B images} + 24: + FOR j := 1 TO Header.Height DO + begin + {Process all the pixels in this line} + FOR i := 0 TO Header.Width - 1 DO + with ImageData[i] do + begin + rgbRed := (255+ImageSource[2+i*3] * AlphaSource[i] + rgbRed * (255 - + AlphaSource[i])) shr 8; + rgbGreen := (255+ImageSource[1+i*3] * AlphaSource[i] + rgbGreen * + (255 - AlphaSource[i])) shr 8; + rgbBlue := (255+ImageSource[i*3] * AlphaSource[i] + rgbBlue * + (255 - AlphaSource[i])) shr 8; + end; + + {Move pointers} + Longint(ImageData) := Longint(ImageData) + BytesPerRowDest; + Longint(ImageSource) := Longint(ImageSource) - BytesPerRowSrc; + Longint(AlphaSource) := Longint(AlphaSource) + BytesPerRowAlpha; + end; + {Palette images with 1 byte for each pixel} + 1,4,8: if Header.ColorType = COLOR_GRAYSCALEALPHA then + FOR j := 1 TO Header.Height DO + begin + {Process all the pixels in this line} + FOR i := 0 TO Header.Width - 1 DO + with ImageData[i], Header.BitmapInfo do begin + rgbRed := (255 + ImageSource[i] * AlphaSource[i] + + rgbRed * (255 - AlphaSource[i])) shr 8; + rgbGreen := (255 + ImageSource[i] * AlphaSource[i] + + rgbGreen * (255 - AlphaSource[i])) shr 8; + rgbBlue := (255 + ImageSource[i] * AlphaSource[i] + + rgbBlue * (255 - AlphaSource[i])) shr 8; + end; + + {Move pointers} + Longint(ImageData) := Longint(ImageData) + BytesPerRowDest; + Longint(ImageSource) := Longint(ImageSource) - BytesPerRowSrc; + Longint(AlphaSource) := Longint(AlphaSource) + BytesPerRowAlpha; + end + else {Palette images} + begin + {Obtain pointer to the transparency chunk} + TransparencyChunk := TChunktRNS(Chunks.ItemFromClass(TChunktRNS)); + PaletteChunk := TChunkPLTE(Chunks.ItemFromClass(TChunkPLTE)); + + FOR j := 1 TO Header.Height DO + begin + {Process all the pixels in this line} + i := 0; Data := @ImageSource[0]; + repeat + CurBit := 0; + + repeat + {Obtains the palette index} + case Header.BitDepth of + 1: PaletteIndex := (Data^ shr (7-(I Mod 8))) and 1; + 2,4: PaletteIndex := (Data^ shr ((1-(I Mod 2))*4)) and $0F; + else PaletteIndex := Data^; + end; + + {Updates the image with the new pixel} + with ImageData[i] do + begin + TransValue := TransparencyChunk.PaletteValues[PaletteIndex]; + rgbRed := (255 + PaletteChunk.Item[PaletteIndex].rgbRed * + TransValue + rgbRed * (255 - TransValue)) shr 8; + rgbGreen := (255 + PaletteChunk.Item[PaletteIndex].rgbGreen * + TransValue + rgbGreen * (255 - TransValue)) shr 8; + rgbBlue := (255 + PaletteChunk.Item[PaletteIndex].rgbBlue * + TransValue + rgbBlue * (255 - TransValue)) shr 8; + end; + + {Move to next data} + inc(i); inc(CurBit, Header.BitmapInfo.bmiHeader.biBitCount); + until CurBit >= 8; + {Move to next source data} + inc(Data); + until i >= Integer(Header.Width); + + {Move pointers} + Longint(ImageData) := Longint(ImageData) + BytesPerRowDest; + Longint(ImageSource) := Longint(ImageSource) - BytesPerRowSrc; + end + end {Palette images} + end {case Header.BitmapInfo.bmiHeader.biBitCount}; + + {Draws the new bitmap on the foreground} + StretchBlt(DC, Rect.Left, Rect.Top, Header.Width, Header.Height, BufferDC, + 0, 0, Header.Width, Header.Height, SRCCOPY); + + {Free bitmap} + SelectObject(BufferDC, OldBitmap); + DeleteObject(BufferBitmap); + DeleteDC(BufferDC); +end; + +{Draws the image into a canvas} +procedure TPngObject.Draw(ACanvas: TCanvas; const Rect: TRect); +var + Header: TChunkIHDR; +begin + {Quit in case there is no header, otherwise obtain it} + if (Chunks.Count = 0) or not (Chunks.GetItem(0) is TChunkIHDR) then Exit; + Header := Chunks.GetItem(0) as TChunkIHDR; + + {Copy the data to the canvas} + case Self.TransparencyMode of + {$IFDEF PartialTransparentDraw} + ptmPartial: + DrawPartialTrans(ACanvas{$IFDEF UseDelphi}.Handle{$ENDIF}, Rect); + {$ENDIF} + ptmBit: DrawTransparentBitmap(ACanvas{$IFDEF UseDelphi}.Handle{$ENDIF}, + Header.ImageData, Header.BitmapInfo.bmiHeader, + pBitmapInfo(@Header.BitmapInfo), Rect, + {$IFDEF UseDelphi}ColorToRGB({$ENDIF}TransparentColor) + {$IFDEF UseDelphi}){$ENDIF} + else + StretchDiBits(ACanvas{$IFDEF UseDelphi}.Handle{$ENDIF}, Rect.Left, + Rect.Top, Rect.Right - Rect.Left, Rect.Bottom - Rect.Top, 0, 0, + Header.Width, Header.Height, Header.ImageData, + pBitmapInfo(@Header.BitmapInfo)^, DIB_RGB_COLORS, SRCCOPY) + end {case} +end; + +{Characters for the header} +const + PngHeader: Array[0..7] of Char = (#137, #80, #78, #71, #13, #10, #26, #10); + +{Loads the image from a stream of data} +procedure TPngObject.LoadFromStream(Stream: TStream); +var + Header : Array[0..7] of Char; + HasIDAT : Boolean; + + {Chunks reading} + ChunkCount : Cardinal; + ChunkLength: Cardinal; + ChunkName : TChunkName; +begin + {Initialize before start loading chunks} + ChunkCount := 0; + ClearChunks(); + {Reads the header} + Stream.Read(Header[0], 8); + + {Test if the header matches} + if Header <> PngHeader then + begin + RaiseError(EPNGInvalidFileHeader, EPNGInvalidFileHeaderText); + Exit; + end; + + + HasIDAT := FALSE; + Chunks.Count := 10; + + {Load chunks} + repeat + inc(ChunkCount); {Increment number of chunks} + if Chunks.Count < ChunkCount then {Resize the chunks list if needed} + Chunks.Count := Chunks.Count + 10; + + {Reads chunk length and invert since it is in network order} + {also checks the Read method return, if it returns 0, it} + {means that no bytes was readed, probably because it reached} + {the end of the file} + if Stream.Read(ChunkLength, 4) = 0 then + begin + {In case it found the end of the file here} + Chunks.Count := ChunkCount - 1; + RaiseError(EPNGUnexpectedEnd, EPNGUnexpectedEndText); + end; + + ChunkLength := ByteSwap(ChunkLength); + {Reads chunk name} + Stream.Read(Chunkname, 4); + + {Here we check if the first chunk is the Header which is necessary} + {to the file in order to be a valid Portable Network Graphics image} + if (ChunkCount = 1) and (ChunkName <> 'IHDR') then + begin + Chunks.Count := ChunkCount - 1; + RaiseError(EPNGIHDRNotFirst, EPNGIHDRNotFirstText); + exit; + end; + + {Has a previous IDAT} + if (HasIDAT and (ChunkName = 'IDAT')) or (ChunkName = 'cHRM') then + begin + dec(ChunkCount); + Stream.Seek(ChunkLength + 4, soFromCurrent); + Continue; + end; + {Tell it has an IDAT chunk} + if ChunkName = 'IDAT' then HasIDAT := TRUE; + + {Creates object for this chunk} + Chunks.SetItem(ChunkCount - 1, CreateClassChunk(Self, ChunkName)); + + {Check if the chunk is critical and unknown} + {$IFDEF ErrorOnUnknownCritical} + if (TChunk(Chunks.Item[ChunkCount - 1]).ClassType = TChunk) and + ((Byte(ChunkName[0]) AND $20) = 0) and (ChunkName <> '') then + begin + Chunks.Count := ChunkCount; + RaiseError(EPNGUnknownCriticalChunk, EPNGUnknownCriticalChunkText); + end; + {$ENDIF} + + {Loads it} + try if not TChunk(Chunks.Item[ChunkCount - 1]).LoadFromStream(Stream, + ChunkName, ChunkLength) then break; + except + Chunks.Count := ChunkCount; + raise; + end; + + {Terminates when it reaches the IEND chunk} + until (ChunkName = 'IEND'); + + {Resize the list to the appropriate size} + Chunks.Count := ChunkCount; + + {Check if there is data} + if not HasIDAT then + RaiseError(EPNGNoImageData, EPNGNoImageDataText); +end; + +{Changing height is not supported} +procedure TPngObject.SetHeight(Value: Integer); +begin + RaiseError(EPNGError, EPNGCannotChangeSizeText); +end; + +{Changing width is not supported} +procedure TPngObject.SetWidth(Value: Integer); +begin + RaiseError(EPNGError, EPNGCannotChangeSizeText); +end; + +{$IFDEF UseDelphi} +{Saves to clipboard format (thanks to Antoine Pottern)} +procedure TPNGObject.SaveToClipboardFormat(var AFormat: Word; + var AData: THandle; var APalette: HPalette); +begin + with TBitmap.Create do + try + Width := Self.Width; + Height := Self.Height; + Self.Draw(Canvas, Rect(0, 0, Width, Height)); + SaveToClipboardFormat(AFormat, AData, APalette); + finally + Free; + end {try} +end; + +{Loads data from clipboard} +procedure TPngObject.LoadFromClipboardFormat(AFormat: Word; + AData: THandle; APalette: HPalette); +begin + with TBitmap.Create do + try + LoadFromClipboardFormat(AFormat, AData, APalette); + Self.AssignHandle(Handle, False, 0); + finally + Free; + end {try} +end; + +{Returns if the image is transparent} +function TPngObject.GetTransparent: Boolean; +begin + Result := (TransparencyMode <> ptmNone); +end; + +{$ENDIF} + +{Saving the PNG image to a stream of data} +procedure TPngObject.SaveToStream(Stream: TStream); +var + j: Integer; +begin + {Reads the header} + Stream.Write(PNGHeader[0], 8); + {Write each chunk} + FOR j := 0 TO Chunks.Count - 1 DO + Chunks.Item[j].SaveToStream(Stream) +end; + +{Prepares the Header chunk} +procedure BuildHeader(Header: TChunkIHDR; Handle: HBitmap; Info: pBitmap; + HasPalette: Boolean); +var + DC: HDC; +begin + {Set width and height} + Header.Width := Info.bmWidth; + Header.Height := abs(Info.bmHeight); + {Set bit depth} + if Info.bmBitsPixel >= 16 then + Header.BitDepth := 8 else Header.BitDepth := Info.bmBitsPixel; + {Set color type} + if Info.bmBitsPixel >= 16 then + Header.ColorType := COLOR_RGB else Header.ColorType := COLOR_PALETTE; + {Set other info} + Header.CompressionMethod := 0; {deflate/inflate} + Header.InterlaceMethod := 0; {no interlace} + + {Prepares bitmap headers to hold data} + Header.PrepareImageData(); + {Copy image data} + DC := CreateCompatibleDC(0); + GetDIBits(DC, Handle, 0, Header.Height, Header.ImageData, + pBitmapInfo(@Header.BitmapInfo)^, DIB_RGB_COLORS); + DeleteDC(DC); +end; + +{Loads the image from a resource} +procedure TPngObject.LoadFromResourceName(Instance: HInst; + const Name: String); +var + ResStream: TResourceStream; +begin + {Creates an especial stream to load from the resource} + try ResStream := TResourceStream.Create(Instance, Name, RT_RCDATA); + except RaiseError(EPNGCouldNotLoadResource, EPNGCouldNotLoadResourceText); + exit; end; + + {Loads the png image from the resource} + try + LoadFromStream(ResStream); + finally + ResStream.Free; + end; +end; + +{Loads the png from a resource ID} +procedure TPngObject.LoadFromResourceID(Instance: HInst; ResID: Integer); +begin + LoadFromResourceName(Instance, String(ResID)); +end; + +{Assigns this tpngobject to another object} +procedure TPngObject.AssignTo(Dest: TPersistent); +{$IFDEF UseDelphi} +var + DeskDC: HDC; + TRNS: TChunkTRNS; +{$ENDIF} +begin + {If the destination is also a TPNGObject make it assign} + {this one} + if Dest is TPNGObject then + TPNGObject(Dest).AssignPNG(Self) + {$IFDEF UseDelphi} + {In case the destination is a bitmap} + else if (Dest is TBitmap) and HeaderPresent then + begin + {Device context} + DeskDC := GetDC(0); + {Copy the data} + TBitmap(Dest).Handle := CreateDIBitmap(DeskDC, + Header.BitmapInfo.bmiHeader, CBM_INIT, Header.ImageData, + pBitmapInfo(@Header.BitmapInfo)^, DIB_RGB_COLORS); + ReleaseDC(0, DeskDC); + {Tests for the best pixelformat} + case Header.BitmapInfo.bmiHeader.biBitCount of + 1: TBitmap(Dest).PixelFormat := pf1Bit; + 4: TBitmap(Dest).PixelFormat := pf4Bit; + 8: TBitmap(Dest).PixelFormat := pf8Bit; + 24: TBitmap(Dest).PixelFormat := pf24Bit; + 32: TBitmap(Dest).PixelFormat := pf32Bit; + end {case Header.BitmapInfo.bmiHeader.biBitCount}; + + {Copy transparency mode} + if (TransparencyMode = ptmBit) then + begin + TRNS := Chunks.ItemFromClass(TChunkTRNS) as TChunkTRNS; + TBitmap(Dest).TransparentColor := TRNS.TransparentColor; + TBitmap(Dest).Transparent := True + end {if (TransparencyMode = ptmBit)} + + end + else + {Unknown destination kind, } + inherited AssignTo(Dest); + {$ENDIF} +end; + +{Assigns from a bitmap object} +procedure TPngObject.AssignHandle(Handle: HBitmap; Transparent: Boolean; + TransparentColor: ColorRef); +var + BitmapInfo: Windows.TBitmap; + HasPalette: Boolean; + + {Chunks} + Header: TChunkIHDR; + PLTE: TChunkPLTE; + IDAT: TChunkIDAT; + IEND: TChunkIEND; + TRNS: TChunkTRNS; +begin + {Obtain bitmap info} + GetObject(Handle, SizeOf(BitmapInfo), @BitmapInfo); + + {Only bit depths 1, 4 and 8 needs a palette} + HasPalette := (BitmapInfo.bmBitsPixel < 16); + + {Clear old chunks and prepare} + ClearChunks(); + + {Create the chunks} + Header := TChunkIHDR.Create(Self); + if HasPalette then PLTE := TChunkPLTE.Create(Self) else PLTE := nil; + if Transparent then TRNS := TChunkTRNS.Create(Self) else TRNS := nil; + IDAT := TChunkIDAT.Create(Self); + IEND := TChunkIEND.Create(Self); + + {Add chunks} + TPNGPointerList(Chunks).Add(Header); + if HasPalette then TPNGPointerList(Chunks).Add(PLTE); + if Transparent then TPNGPointerList(Chunks).Add(TRNS); + TPNGPointerList(Chunks).Add(IDAT); + TPNGPointerList(Chunks).Add(IEND); + + {This method will fill the Header chunk with bitmap information} + {and copy the image data} + BuildHeader(Header, Handle, @BitmapInfo, HasPalette); + {In case there is a image data, set the PLTE chunk fCount variable} + {to the actual number of palette colors which is 2^(Bits for each pixel)} + if HasPalette then PLTE.fCount := 1 shl BitmapInfo.bmBitsPixel; + + {In case it is a transparent bitmap, prepares it} + if Transparent then TRNS.TransparentColor := TransparentColor; + +end; + +{Assigns from another PNG} +procedure TPngObject.AssignPNG(Source: TPNGObject); +var + J: Integer; +begin + {Copy properties} + InterlaceMethod := Source.InterlaceMethod; + MaxIdatSize := Source.MaxIdatSize; + CompressionLevel := Source.CompressionLevel; + Filters := Source.Filters; + + {Clear old chunks and prepare} + ClearChunks(); + Chunks.Count := Source.Chunks.Count; + {Create chunks and makes a copy from the source} + FOR J := 0 TO Chunks.Count - 1 DO + with Source.Chunks do + begin + Chunks.SetItem(J, TChunkClass(TChunk(Item[J]).ClassType).Create(Self)); + TChunk(Chunks.Item[J]).Assign(TChunk(Item[J])); + end {with}; +end; + +{Returns a alpha data scanline} +function TPngObject.GetAlphaScanline(const LineIndex: Integer): pByteArray; +begin + with Header do + if (ColorType = COLOR_RGBALPHA) or (ColorType = COLOR_GRAYSCALEALPHA) then + Longint(Result) := Longint(ImageAlpha) + (LineIndex * Longint(Width)) + else Result := nil; {In case the image does not use alpha information} +end; + +{$IFDEF Store16bits} +{Returns a png data extra scanline} +function TPngObject.GetExtraScanline(const LineIndex: Integer): Pointer; +begin + with Header do + Longint(Result) := (Longint(ExtraImageData) + ((Longint(Height) - 1) * + BytesPerRow)) - (LineIndex * BytesPerRow); +end; +{$ENDIF} + +{Returns a png data scanline} +function TPngObject.GetScanline(const LineIndex: Integer): Pointer; +begin + with Header do + Longint(Result) := (Longint(ImageData) + ((Longint(Height) - 1) * + BytesPerRow)) - (LineIndex * BytesPerRow); +end; + +{Initialize gamma table} +procedure TPngObject.InitializeGamma; +var + i: Integer; +begin + {Build gamma table as if there was no gamma} + FOR i := 0 to 255 do + begin + GammaTable[i] := i; + InverseGamma[i] := i; + end {for i} +end; + +{Returns the transparency mode used by this png} +function TPngObject.GetTransparencyMode: TPNGTransparencyMode; +var + TRNS: TChunkTRNS; +begin + with Header do + begin + Result := ptmNone; {Default result} + {Gets the TRNS chunk pointer} + TRNS := Chunks.ItemFromClass(TChunkTRNS) as TChunkTRNS; + + {Test depending on the color type} + case ColorType of + {This modes are always partial} + COLOR_RGBALPHA, COLOR_GRAYSCALEALPHA: Result := ptmPartial; + {This modes support bit transparency} + COLOR_RGB, COLOR_GRAYSCALE: if TRNS <> nil then Result := ptmBit; + {Supports booth translucid and bit} + COLOR_PALETTE: + {A TRNS chunk must be present, otherwise it won't support transparency} + if TRNS <> nil then + if TRNS.BitTransparency then + Result := ptmBit else Result := ptmPartial + end {case} + + end {with Header} +end; + +{Add a text chunk} +procedure TPngObject.AddtEXt(const Keyword, Text: String); +var + TextChunk: TChunkTEXT; +begin + TextChunk := Chunks.Add(TChunkText) as TChunkTEXT; + TextChunk.Keyword := Keyword; + TextChunk.Text := Text; +end; + +{Add a text chunk} +procedure TPngObject.AddzTXt(const Keyword, Text: String); +var + TextChunk: TChunkzTXt; +begin + TextChunk := Chunks.Add(TChunkText) as TChunkzTXt; + TextChunk.Keyword := Keyword; + TextChunk.Text := Text; +end; + +{Removes the image transparency} +procedure TPngObject.RemoveTransparency; +var + TRNS: TChunkTRNS; +begin + TRNS := Chunks.ItemFromClass(TChunkTRNS) as TChunkTRNS; + if TRNS <> nil then Chunks.RemoveChunk(TRNS) +end; + +{Generates alpha information} +procedure TPngObject.CreateAlpha; +var + TRNS: TChunkTRNS; +begin + {Generates depending on the color type} + with Header do + case ColorType of + {Png allocates different memory space to hold alpha information} + {for these types} + COLOR_GRAYSCALE, COLOR_RGB: + begin + {Transform into the appropriate color type} + if ColorType = COLOR_GRAYSCALE then + ColorType := COLOR_GRAYSCALEALPHA + else ColorType := COLOR_RGBALPHA; + {Allocates memory to hold alpha information} + GetMem(ImageAlpha, Integer(Width) * Integer(Height)); + FillChar(ImageAlpha^, Integer(Width) * Integer(Height), #255); + end; + {Palette uses the TChunktRNS to store alpha} + COLOR_PALETTE: + begin + {Gets/creates TRNS chunk} + if Chunks.ItemFromClass(TChunkTRNS) = nil then + TRNS := Chunks.Add(TChunkTRNS) as TChunkTRNS + else + TRNS := Chunks.ItemFromClass(TChunkTRNS) as TChunkTRNS; + + {Prepares the TRNS chunk} + with TRNS do + begin + Fillchar(PaletteValues[0], 256, 255); + fDataSize := 1 shl Header.BitDepth; + fBitTransparency := False + end {with Chunks.Add}; + end; + end {case Header.ColorType} + +end; + +{Returns transparent color} +function TPngObject.GetTransparentColor: TColor; +var + TRNS: TChunkTRNS; +begin + TRNS := Chunks.ItemFromClass(TChunkTRNS) as TChunkTRNS; + {Reads the transparency chunk to get this info} + if Assigned(TRNS) then Result := TRNS.TransparentColor + else Result := 0 +end; + +{$OPTIMIZATION OFF} +procedure TPngObject.SetTransparentColor(const Value: TColor); +var + TRNS: TChunkTRNS; +begin + if HeaderPresent then + {Tests the ColorType} + case Header.ColorType of + {Not allowed for this modes} + COLOR_RGBALPHA, COLOR_GRAYSCALEALPHA: Self.RaiseError( + EPNGCannotChangeTransparent, EPNGCannotChangeTransparentText); + {Allowed} + COLOR_PALETTE, COLOR_RGB, COLOR_GRAYSCALE: + begin + TRNS := Chunks.ItemFromClass(TChunkTRNS) as TChunkTRNS; + if not Assigned(TRNS) then TRNS := Chunks.Add(TChunkTRNS) as TChunkTRNS; + + {Sets the transparency value from TRNS chunk} + TRNS.TransparentColor := {$IFDEF UseDelphi}ColorToRGB({$ENDIF}Value{$IFDEF UseDelphi}){$ENDIF} + end {COLOR_PALETTE, COLOR_RGB, COLOR_GRAYSCALE)} + end {case} +end; + +{Returns if header is present} +function TPngObject.HeaderPresent: Boolean; +begin + Result := ((Chunks.Count <> 0) and (Chunks.Item[0] is TChunkIHDR)) +end; + +{Returns pixel for png using palette and grayscale} +function GetByteArrayPixel(const png: TPngObject; const X, Y: Integer): TColor; +var + ByteData: Byte; + DataDepth: Byte; +begin + with png, Header do + begin + {Make sure the bitdepth is not greater than 8} + DataDepth := BitDepth; + if DataDepth > 8 then DataDepth := 8; + {Obtains the byte containing this pixel} + ByteData := pByteArray(png.Scanline[Y])^[X div (8 div DataDepth)]; + {Moves the bits we need to the right} + ByteData := (ByteData shr ((8 - DataDepth) - + (X mod (8 div DataDepth)) * DataDepth)); + {Discard the unwanted pixels} + ByteData:= ByteData and ($FF shr (8 - DataDepth)); + + {For palette mode map the palette entry and for grayscale convert and + returns the intensity} + case ColorType of + COLOR_PALETTE: + with TChunkPLTE(png.Chunks.ItemFromClass(TChunkPLTE)).Item[ByteData] do + Result := rgb(GammaTable[rgbRed], GammaTable[rgbGreen], + GammaTable[rgbBlue]); + COLOR_GRAYSCALE: + begin + ByteData := GammaTable[ByteData * ((1 shl DataDepth) + 1)]; + Result := rgb(ByteData, ByteData, ByteData); + end; + else Result := 0; + end {case}; + end {with} +end; + +{In case vcl units are not being used} +{$IFNDEF UseDelphi} +function ColorToRGB(const Color: TColor): COLORREF; +begin + Result := Color +end; +{$ENDIF} + +{Sets a pixel for grayscale and palette pngs} +procedure SetByteArrayPixel(const png: TPngObject; const X, Y: Integer; + const Value: TColor); +const + ClearFlag: Array[1..8] of Integer = (1, 3, 0, 15, 0, 0, 0, $FF); +var + ByteData: pByte; + DataDepth: Byte; + ValEntry: Byte; +begin + with png.Header do + begin + {Map into a palette entry} + ValEntry := GetNearestPaletteIndex(Png.Palette, ColorToRGB(Value)); + + {16 bits grayscale extra bits are discarted} + DataDepth := BitDepth; + if DataDepth > 8 then DataDepth := 8; + {Gets a pointer to the byte we intend to change} + ByteData := @pByteArray(png.Scanline[Y])^[X div (8 div DataDepth)]; + {Clears the old pixel data} + ByteData^ := ByteData^ and not (ClearFlag[DataDepth] shl ((8 - DataDepth) - + (X mod (8 div DataDepth)) * DataDepth)); + + {Setting the new pixel} + ByteData^ := ByteData^ or (ValEntry shl ((8 - DataDepth) - + (X mod (8 div DataDepth)) * DataDepth)); + end {with png.Header} +end; + +{Returns pixel when png uses RGB} +function GetRGBLinePixel(const png: TPngObject; + const X, Y: Integer): TColor; +begin + with pRGBLine(png.Scanline[Y])^[X] do + Result := RGB(rgbtRed, rgbtGreen, rgbtBlue) +end; + +{Sets pixel when png uses RGB} +procedure SetRGBLinePixel(const png: TPngObject; + const X, Y: Integer; Value: TColor); +begin + with pRGBLine(png.Scanline[Y])^[X] do + begin + rgbtRed := GetRValue(Value); + rgbtGreen := GetGValue(Value); + rgbtBlue := GetBValue(Value) + end +end; + +{Sets a pixel} +procedure TPngObject.SetPixels(const X, Y: Integer; const Value: TColor); +begin + if (X in [0..Width - 1]) and (Y in [0..Height - 1]) then + with Header do + begin + if ColorType in [COLOR_GRAYSCALE, COLOR_PALETTE] then + SetByteArrayPixel(Self, X, Y, Value) + else + SetRGBLinePixel(Self, X, Y, Value) + end {with} +end; + +{Returns a pixel} +function TPngObject.GetPixels(const X, Y: Integer): TColor; +begin + if (X in [0..Width - 1]) and (Y in [0..Height - 1]) then + with Header do + begin + if ColorType in [COLOR_GRAYSCALE, COLOR_PALETTE] then + Result := GetByteArrayPixel(Self, X, Y) + else + Result := GetRGBLinePixel(Self, X, Y) + end {with} + else Result := 0 +end; + +{Returns the image palette} +function TPngObject.GetPalette: HPALETTE; +var + LogPalette: TMaxLogPalette; + i: Integer; +begin + {Palette is avaliable for COLOR_PALETTE and COLOR_GRAYSCALE modes} + if (Header.ColorType in [COLOR_PALETTE, COLOR_GRAYSCALE]) then + begin + {In case the pal} + if TempPalette = 0 then + with LogPalette do + begin + {Prepares the new palette} + palVersion := $300; + palNumEntries := 256; + {Copy entries} + for i := 0 to LogPalette.palNumEntries - 1 do + begin + palPalEntry[i].peRed := Header.BitmapInfo.bmiColors[i].rgbRed; + palPalEntry[i].peGreen := Header.BitmapInfo.bmiColors[i].rgbGreen; + palPalEntry[i].peBlue := Header.BitmapInfo.bmiColors[i].rgbBlue; + palPalEntry[i].peFlags := 0; + end {for i}; + {Creates the palette} + TempPalette := CreatePalette(pLogPalette(@LogPalette)^); + end {with LogPalette, if Temppalette = 0} + end {if Header.ColorType in ...}; + Result := TempPalette; +end; + +initialization + {Initialize} + ChunkClasses := nil; + {crc table has not being computed yet} + crc_table_computed := FALSE; + {Register the necessary chunks for png} + RegisterCommonChunks; + {Registers TPNGObject to use with TPicture} + {$IFDEF UseDelphi}{$IFDEF RegisterGraphic} + TPicture.RegisterFileFormat('PNG', 'Portable Network Graphics', TPNGObject); + {$ENDIF}{$ENDIF} +finalization + {$IFDEF UseDelphi}{$IFDEF RegisterGraphic} + TPicture.UnregisterGraphicClass(TPNGObject); + {$ENDIF}{$ENDIF} + {Free chunk classes} + FreeChunkClassList; +end. + + -- cgit v1.2.3