unit sdlstreams;
{
$Id: sdlstreams.pas,v 1.1 2004/02/05 00:08:20 savage Exp $
}
{******************************************************************}
{ }
{ SDL - Simple DirectMedia Layer }
{ Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga }
{ }
{ Portions created by Chris Bruner are }
{ Copyright (C) 2002 Chris Bruner. }
{ }
{ Contributor(s) }
{ -------------- }
{ }
{ }
{ Obtained through: }
{ Joint Endeavour of Delphi Innovators ( Project JEDI ) }
{ }
{ You may retrieve the latest version of this file at the Project }
{ JEDI home page, located at http://delphi-jedi.org }
{ }
{ The contents of this file are used with permission, subject to }
{ the Mozilla Public License Version 1.1 (the "License"); you may }
{ not use this file except in compliance with the License. You may }
{ obtain a copy of the License at }
{ http://www.mozilla.org/NPL/NPL-1_1Final.html }
{ }
{ Software distributed under the License is distributed on an }
{ "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or }
{ implied. See the License for the specific language governing }
{ rights and limitations under the License. }
{ }
{ Description }
{ ----------- }
{ Shows how to use OpenGL to do 2D and 3D with the SDL libraries }
{ }
{ }
{ Requires }
{ -------- }
{ SDL runtime libary somewhere in your path }
{ The Latest SDL runtime can be found on http://www.libsdl.org }
{ }
{ Programming Notes }
{ ----------------- }
{ }
{ }
{ }
{ }
{ }
{ Revision History }
{ ---------------- }
{ January 11 2002 - CB : Software embraced and extended by }
{ Chris Bruner of Crystal Software }
{ (Canada) Inc. }
{ }
{ February 11 2002 - DL : Added FreePascal support as suggested }
{ by "QuePasha Pepe" <mrkroket@hotmail.com> }
{ }
{******************************************************************}
{
$Log: sdlstreams.pas,v $
Revision 1.1 2004/02/05 00:08:20 savage
Module 1.0 release
}
{$i jedi-sdl.inc}
interface
uses
Classes,
SysUtils,
sdl,
sdlutils;
{$IFDEF FPC}
type
EinvalidContainer=class(Exception);
{$ENDIF}
function LoadSDLBMPFromStream( Stream : TStream ) : PSDL_Surface;
procedure SaveSDLBMPToStream( SDL_Surface : PSDL_Surface; stream : TStream );
function SDL_Swap16( D : UInt16 ) : Uint16;
function SDL_Swap32( D : UInt32 ) : Uint32;
function SDLStreamSetup( stream : TStream ) : PSDL_RWops;
// this only closes the SDL_RWops part of the stream, not the stream itself
procedure SDLStreamCloseRWops( SDL_RWops : PSDL_RWops );
implementation
function SDL_Swap16( D : UInt16 ) : Uint16;
begin
Result := ( D shl 8 ) or ( D shr 8 );
end;
function SDL_Swap32( D : UInt32 ) : Uint32;
begin
Result := ( ( D shl 24 ) or ( ( D shl 8 ) and $00FF0000 ) or ( ( D shr 8 ) and $0000FF00 ) or ( D shr 24 ) );
end;
(*function SDL_Swap64(D : UInt64) : Uint64;
var hi,lo : Uint32;
begin
// Separate into high and low 32-bit resultues and swap them
lo := Uint32(D and $0FFFFFFFF); // bloody pascal is too tight in it's type checking!
D := D shr 32;
hi = Uint32((D and $FFFFFFFF));
result = SDL_Swap32(lo);
result := result shl 32;
result := result or SDL_Swap32(hi);
end;
*)
function SdlStreamSeek( context : PSDL_RWops; offset : Integer; whence : Integer ) : integer; cdecl;
var
stream : TStream;
origin : Word;
begin
stream := TStream( context.unknown );
if ( stream = nil ) then
raise EInvalidContainer.Create( 'SDLStreamSeek on nil' );
case whence of
0 : origin := soFromBeginning; // Offset is from the beginning of the resource. Seek moves to the position Offset. Offset must be >= 0.
1 : origin := soFromCurrent; // Offset is from the current position in the resource. Seek moves to Position + Offset.
2 : origin := soFromEnd;
else
origin := soFromBeginning; // just in case
end;
Result := stream.Seek( offset, origin );
end;
function SDLStreamWrite( context : PSDL_RWops; Ptr : Pointer;
size : Integer; num : Integer ) : Integer; cdecl;
var
stream : TStream;
begin
stream := TStream( context.unknown );
if ( stream = nil ) then
raise EInvalidContainer.Create( 'SDLStreamWrite on nil' );
try
Result := stream.Write( Ptr^, Size * num ) div size;
except
Result := -1;
end;
end;
function SdlStreamRead( context : PSDL_RWops; Ptr : Pointer; size : Integer; maxnum
: Integer ) : Integer; cdecl;
var
stream : TStream;
begin
stream := TStream( context.unknown );
if ( stream = nil ) then
raise EInvalidContainer.Create( 'SDLStreamRead on nil' );
try
Result := stream.read( Ptr^, Size * maxnum ) div size;
except
Result := -1;
end;
end;
function SDLStreamClose( context : PSDL_RWops ) : Integer; cdecl;
var
stream : TStream;
begin
stream := TStream( context.unknown );
if ( stream = nil ) then
raise EInvalidContainer.Create( 'SDLStreamClose on nil' );
stream.Free;
Result := 1;
end;
function SDLStreamSetup( stream : TStream ) : PSDL_RWops;
begin
result := SDL_AllocRW;
if ( result = nil ) then
raise EInvalidContainer.Create( 'could not create SDLStream on nil' );
result.unknown := TUnknown( stream );
result.seek := SDLStreamSeek;
result.read := SDLStreamRead;
result.write := SDLStreamWrite;
result.close := SDLStreamClose;
Result.type_ := 2; // TUnknown
end;
// this only closes the SDL part of the stream, not the context
procedure SDLStreamCloseRWops( SDL_RWops : PSDL_RWops );
begin
SDL_FreeRW( SDL_RWops );
end;
function LoadSDLBMPFromStream( stream : TStream ) : PSDL_Surface;
var
SDL_RWops : PSDL_RWops;
begin
SDL_RWops := SDLStreamSetup( stream );
result := SDL_LoadBMP_RW( SDL_RWops, 0 );
SDLStreamCloseRWops( SDL_RWops );
end;
procedure SaveSDLBMPToStream( SDL_Surface : PSDL_Surface; stream : TStream );
var
SDL_RWops : PSDL_RWops;
begin
SDL_RWops := SDLStreamSetup( stream );
SDL_SaveBMP_RW( SDL_Surface, SDL_RWops, 0 );
SDLStreamCloseRWops( SDL_RWops );
end;
end.
