Added support for transparency in PNG images - if a PNG with transparency is loaded as 'Transparent' texture type, then the alpha-channel is set according to the transparency information in the file

git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@270 b956fd51-792f-4845-bead-9b4dfca2ff2c

1 files changed, 34 insertions, 2 deletions

diff --git a/Game/Code/Classes/UTexture.pas b/Game/Code/Classes/UTexture.pas
index 0eae68a2..da603ec9 100644
--- a/Game/Code/Classes/UTexture.pas
+++ b/Game/Code/Classes/UTexture.pas
@@ -193,6 +193,10 @@ var
   TextureB:   TBitmap;

   TextureJ:   TJPEGImage;

   TexturePNG: TPNGObject;

+  TextureAlpha: array of byte;

+  AlphaPtr:   PByte;

+  TransparentColor: TColor;

+  PixelColor: TColor;

 

   Pet:        integer;

   Pet2:       integer;

@@ -246,6 +250,27 @@ begin
         Exit;

     end;

     TextureB.Assign(TexturePNG);

+    // transparent png hack start (part 1 of 2)

+    if (Typ = 'Transparent') and (TexturePNG.TransparencyMode = ptmPartial) then

+    begin

+      setlength(TextureAlpha, TextureB.Width*TextureB.Height);

+      if (TexturePNG.Header.ColorType = COLOR_GRAYSCALEALPHA) or

+         (TexturePNG.Header.ColorType = COLOR_RGBALPHA) then

+      begin

+        // i would have preferred english variables here but i use Pet because i'm lazy

+        for Pet := 0 to TextureB.Height - 1 do

+        begin

+          AlphaPtr := PByte(TexturePNG.AlphaScanline[Pet]);

+          for Pet2 := 0 to TextureB.Width - 1 do

+          begin

+            TextureAlpha[Pet*TextureB.Width+Pet2]:= AlphaPtr^;

+            Inc(AlphaPtr);

+          end;

+        end;

+      end;

+    end else

+      setlength(TextureAlpha,0); // just no special transparency for unimplemented transparency types (ptmBit)

+    // transparent png hack end

     TexturePNG.Free;

   end;

 

@@ -357,11 +382,13 @@ begin
     TexNewH := Round(Power(2, Ceil(Log2(TexOrygH))));

     TextureB.Width := TexNewW;

     TextureB.Height := TexNewH;

+

     // kopiowanie

     for Pet := 0 to TexOrygH-1 do begin

       for Pet2 := 0 to TexOrygW-1 do begin

         Pix := TextureB.Canvas.Pixels[Pet2, Pet];

-        if ((Pix = $fefefe) or (Pix = Col)) then begin //Small fix, that caused artefacts to be drawn (#fe == dec254)

+                                           // ,- part of transparent png hack

+        if ((Pix = $fefefe) or (Pix = Col)) and (length(TextureAlpha)=0) then begin //Small fix, that caused artefacts to be drawn (#fe == dec254)

           TextureD32[Pet*TexNewW + Pet2 + 1, 1] := 0;

           TextureD32[Pet*TexNewW + Pet2 + 1, 2] := 0;

           TextureD32[Pet*TexNewW + Pet2 + 1, 3] := 0;

@@ -370,7 +397,12 @@ begin
           TextureD32[Pet*TexNewW + Pet2+1, 1] := Pix;

           TextureD32[Pet*TexNewW + Pet2+1, 2] := Pix div 256;

           TextureD32[Pet*TexNewW + Pet2+1, 3] := Pix div (256*256);

-          TextureD32[Pet*TexNewW + Pet2+1, 4] := 255;

+          // transparent png hack start (part 2 of 2)

+          if (Format = 'PNG') and (length(TextureAlpha) <> 0) then begin

+            TextureD32[Pet*TexNewW+Pet2+1,4]:=TextureAlpha[Pet*TexOrygW+Pet2];

+          end else

+          // transparent png hack end

+            TextureD32[Pet*TexNewW + Pet2+1, 4] := 255;

         end;

       end;

     end;