* added LibPNG Support

glBitmap.pas

@@ -1,6 +1,10 @@
 {***********************************************************
 glBitmap by Steffen Xonna aka Lossy eX (2003-2008)
 http://www.opengl24.de/index.php?cat=header&file=glbitmap
+
+modified by Delphi OpenGL Community (http://delphigl.com/)
+
+
 ------------------------------------------------------------
 The contents of this file are used with permission, subject to
 the Mozilla Public License Version 1.1 (the "License"); you may
@@ -230,7 +234,7 @@ unit glBitmap;
 {.$DEFINE GLB_NATIVE_OGL_DYNAMIC}
 
 // activate to enable the support for SDL_surfaces
-{$DEFINE GLB_SDL}
+{.$DEFINE GLB_SDL}
 
 // activate  to enable the support for TBitmap from Delphi (not lazarus)
 {.$DEFINE GLB_DELPHI}
@@ -239,7 +243,7 @@ unit glBitmap;
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // activate to enable the support of SDL_image to load files. (READ ONLY)
 // If you enable SDL_image all other libraries will be ignored!
-{$DEFINE GLB_SDL_IMAGE}
+{.$DEFINE GLB_SDL_IMAGE}
 
 // activate to enable png support with the unit pngimage. You can download it from http://pngdelphi.sourceforge.net/
 // if you enable pngimage the libPNG will be ignored
@@ -248,7 +252,7 @@ unit glBitmap;
 // activate to use the libPNG http://www.libpng.org/
 // You will need an aditional header.
 // http://www.opengl24.de/index.php?cat=header&file=libpng
-{.$DEFINE GLB_LIB_PNG}
+{$DEFINE GLB_LIB_PNG}
 
 // if you enable delphi jpegs the libJPEG will be ignored
 {.$DEFINE GLB_DELPHI_JPEG}
@@ -260,7 +264,7 @@ unit glBitmap;
 
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-// PRIVATE: DO not change anything! //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// PRIVATE: do not change anything! //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Delphi Versions
 {$IFDEF fpc}
@@ -677,12 +681,6 @@ var
 {$ENDIF}
 
 type
-////////////////////////////////////////////////////////////////////////////////////////////////////
-  EglBitmapException               = class(Exception);
-  EglBitmapSizeToLargeException    = class(EglBitmapException);
-  EglBitmapNonPowerOfTwoException  = class(EglBitmapException);
-  EglBitmapUnsupportedFormat       = class(EglBitmapException);
-
 ////////////////////////////////////////////////////////////////////////////////////////////////////
   TglBitmapFormat = (
     tfEmpty = 0, //must be smallest value!
@@ -765,6 +763,14 @@ type
      nm3x3,
      nm5x5);
 
+ ////////////////////////////////////////////////////////////////////////////////////////////////////
+   EglBitmapException               = class(Exception);
+   EglBitmapSizeToLargeException    = class(EglBitmapException);
+   EglBitmapNonPowerOfTwoException  = class(EglBitmapException);
+   EglBitmapUnsupportedFormat       = class(EglBitmapException)
+     constructor Create(const aFormat: TglBitmapFormat);
+   end;
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////
   TglBitmapColorRec = packed record
   case Integer of
@@ -1126,7 +1132,7 @@ implementation
     *)
 
 uses
-  Math, syncobjs;
+  Math, syncobjs, typinfo;
 
 type
 ////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -1651,6 +1657,12 @@ var
   FormatDescriptorCS: TCriticalSection;
   FormatDescriptors: array[TglBitmapFormat] of TFormatDescriptor;
 
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+constructor EglBitmapUnsupportedFormat.Create(const aFormat: TglBitmapFormat);
+begin
+  inherited Create(GetEnumName(TypeInfo(TglBitmapFormat), Integer(aFormat)));
+end;
+
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 function glBitmapPosition(X, Y: Integer): TglBitmapPixelPosition;
 begin
@@ -1757,19 +1769,15 @@ begin
         tfS3tcDtx1RGBA, tfS3tcDtx3RGBA, tfS3tcDtx5RGBA]) then
     result := result + [ftDDS];
 
-  (* TODO
   {$IFDEF GLB_SUPPORT_PNG_WRITE}
   if aFormat in [
-    tfAlpha4, tfAlpha8, tfAlpha12, tfAlpha16,
-    tfLuminance4, tfLuminance8, tfLuminance12, tfLuminance16,
-    tfuminance4Alpha4, tfLuminance6Alpha2, tfLuminance8Alpha8, tfLuminance12Alpha4, tfLuminance12Alpha12, tfLuminance16Alpha16,
-    tfR3G3B2, tfRGB4, tfRGB5, tfRGB8, tfRGB10, tfRGB12, tfRGB16,
-    tfRGBA2, tfRGBA4, tfRGB5A1, tfRGBA8, tfRGB10A2, tfRGBA12, tfRGBA16,
-    tfDepth16, tfDepth24, tfDepth32]
-  then
+      tfAlpha8, tfLuminance8, tfLuminance8Alpha8,
+      tfRGB8, tfRGBA8,
+      tfBGR8, tfBGRA8] then
     result := result + [ftPNG];
   {$ENDIF}
 
+(* TODO
   {$IFDEF GLB_SUPPORT_JPEG_WRITE}
   if Format in [
     tfAlpha4, tfAlpha8, tfAlpha12, tfAlpha16,
@@ -1779,16 +1787,6 @@ begin
   then
     result := result + [ftJPEG];
   {$ENDIF}
-
-  if aFormat in [
-    tfAlpha4, tfAlpha8, tfAlpha12, tfAlpha16,
-    tfLuminance4, tfLuminance8, tfLuminance12, tfLuminance16,
-    tfuminance4Alpha4, tfLuminance6Alpha2, tfLuminance8Alpha8, tfLuminance12Alpha4, tfLuminance12Alpha12, tfLuminance16Alpha16,
-    tfR3G3B2, tfRGB4, tfRGB5, tfRGB8, tfRGB10, tfRGB12, tfRGB16,
-    tfRGBA2, tfRGBA4, tfRGB5A1, tfRGBA8, tfRGB10A2, tfRGBA12, tfRGBA16,
-    tfDepth16, tfDepth24, tfDepth32]
-  then
-    result := result + [ftDDS, ftTGA, ftBMP];
   *)
 end;
 
@@ -4220,7 +4218,7 @@ begin
   if fFormat = aValue then
     exit;
   if TFormatDescriptor.Get(Format).PixelSize <> TFormatDescriptor.Get(aValue).PixelSize then
-    raise EglBitmapUnsupportedFormat.Create('SetFormat');
+    raise EglBitmapUnsupportedFormat.Create(Format);
   SetDataPointer(Data, aValue, Width, Height);
 end;
 
@@ -4491,7 +4489,7 @@ procedure TglBitmap.SaveToStream(const aStream: TStream; const aFileType: TglBit
 begin
   case aFileType of
     {$IFDEF GLB_SUPPORT_PNG_WRITE}
-    ftPNG:  SavePng(aStream);
+    ftPNG:  SavePNG(aStream);
     {$ENDIF}
     {$IFDEF GLB_SUPPORT_JPEG_WRITE}
     ftJPEG: SaveJPEG(aStream);
@@ -4609,7 +4607,7 @@ begin
 
   FormatDesc := TFormatDescriptor.Get(Format);
   if FormatDesc.IsCompressed then
-    raise EglBitmapUnsupportedFormat.Create('AssignToSurface');
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   if Assigned(Data) then begin
     case Trunc(FormatDesc.PixelSize) of
@@ -4618,7 +4616,7 @@ begin
       3: TempDepth := 24;
       4: TempDepth := 32;
     else
-      raise EglBitmapUnsupportedFormat.Create('AssignToSurface');
+      raise EglBitmapUnsupportedFormat.Create(Format);
     end;
 
     aSurface := SDL_CreateRGBSurface(SDL_SWSURFACE, Width, Height, TempDepth,
@@ -4952,10 +4950,8 @@ end;
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 function TglBitmap.AddAlphaFromFunc(const aFunc: TglBitmapFunction; const aArgs: Pointer): Boolean;
 begin
-  (* TODO
-  if not FormatIsUncompressed(InternalFormat) then
-    raise EglBitmapUnsupportedFormatFormat.Create('AddAlphaFromFunc - ' + UNSUPPORTED_FORMAT);
-  *)
+  if TFormatDescriptor.Get(Format).IsCompressed then
+    raise EglBitmapUnsupportedFormat.Create(Format);
   result := AddFunc(Self, aFunc, false, TFormatDescriptor.Get(Format).WithAlpha, aArgs);
 end;
 
@@ -5132,7 +5128,7 @@ begin
   FormatDesc := TFormatDescriptor.Get(Format);
   if Assigned(Data) then begin
     if FormatDesc.IsCompressed or not FormatDesc.HasAlpha then
-      raise EglBitmapUnsupportedFormat.Create('RemoveAlpha');
+      raise EglBitmapUnsupportedFormat.Create(Format);
     result := ConvertTo(FormatDesc.WithoutAlpha);
   end;
 end;
@@ -5533,7 +5529,7 @@ var
   png_info: png_infop;
 
   TempHeight, TempWidth: Integer;
-  Format: TglBitmapInternalFormat;
+  Format: TglBitmapFormat;
 
   png_data: pByte;
   png_rows: array of pByte;
@@ -5546,9 +5542,9 @@ begin
 
   try
     // signature
-    StreamPos := Stream.Position;
-    Stream.Read(signature, 8);
-    Stream.Position := StreamPos;
+    StreamPos := aStream.Position;
+    aStream.Read(signature, 8);
+    aStream.Position := StreamPos;
 
     if png_check_sig(@signature, 8) <> 0 then begin
       // png read struct
@@ -5564,7 +5560,7 @@ begin
       end;
 
       // set read callback
-      png_set_read_fn(png, stream, glBitmap_libPNG_read_func);
+      png_set_read_fn(png, aStream, glBitmap_libPNG_read_func);
 
       // read informations
       png_read_info(png, png_info);
@@ -5742,27 +5738,30 @@ var
   LineSize: Integer;
   ColorType: Integer;
   Row: Integer;
+  FormatDesc: TFormatDescriptor;
 begin
-  if not (ftPNG in FormatGetSupportedFiles (InternalFormat)) then
-    raise EglBitmapUnsupportedInternalFormat.Create('SavePng - ' + UNSUPPORTED_INTERNAL_FORMAT);
+  if not (ftPNG in FormatGetSupportedFiles(Format)) then
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   if not init_libPNG then
-    raise Exception.Create('SavePNG - unable to initialize libPNG.');
+    raise Exception.Create('unable to initialize libPNG.');
 
   try
-    case FInternalFormat of
-      ifAlpha, ifLuminance, ifDepth8:
+    case Format of
+      tfAlpha8, tfLuminance8:
         ColorType := PNG_COLOR_TYPE_GRAY;
-      ifLuminanceAlpha:
+      tfLuminance8Alpha8:
         ColorType := PNG_COLOR_TYPE_GRAY_ALPHA;
-      ifBGR8, ifRGB8:
+      tfBGR8, tfRGB8:
         ColorType := PNG_COLOR_TYPE_RGB;
-      ifBGRA8, ifRGBA8:
+      tfBGRA8, tfRGBA8:
         ColorType := PNG_COLOR_TYPE_RGBA;
       else
-        raise EglBitmapUnsupportedInternalFormat.Create('SavePng - ' + UNSUPPORTED_INTERNAL_FORMAT);
+        raise EglBitmapUnsupportedFormat.Create(Format);
     end;
-    LineSize := Trunc(FormatGetSize(FInternalFormat) * Width);
+
+    FormatDesc := TFormatDescriptor.Get(Format);
+    LineSize := FormatDesc.GetSize(Width, 1);
 
     // creating array for scanline
     SetLength(png_rows, Height);
@@ -5785,12 +5784,12 @@ begin
       end;
 
       // set read callback
-      png_set_write_fn(png, stream, glBitmap_libPNG_write_func, nil);
+      png_set_write_fn(png, aStream, glBitmap_libPNG_write_func, nil);
 
       // set compression
       png_set_compression_level(png, 6);
 
-      if InternalFormat in [ifBGR8, ifBGRA8] then
+      if Format in [tfBGR8, tfBGRA8] then
         png_set_bgr(png);
 
       png_set_IHDR(png, png_info, Width, Height, 8, ColorType, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
@@ -6559,7 +6558,7 @@ var
 
 begin
   if not (ftBMP in FormatGetSupportedFiles(Format)) then
-    raise EglBitmapUnsupportedFormat.Create('SaveBMP');
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   Converter  := nil;
   FormatDesc := TFormatDescriptor.Get(Format);
@@ -6624,7 +6623,7 @@ begin
         Info.biCompression := BMP_COMP_BITFIELDS;
       end;
     else
-      raise EglBitmapUnsupportedFormat.Create('SaveBMP - ' + UNSUPPORTED_FORMAT);
+      raise EglBitmapUnsupportedFormat.Create(Format);
     end;
     Info.biXPelsPerMeter := 2835;
     Info.biYPelsPerMeter := 2835;
@@ -7020,7 +7019,7 @@ var
   Converter: TFormatDescriptor;
 begin
   if not (ftTGA in FormatGetSupportedFiles(Format)) then
-    raise EglBitmapUnsupportedFormat.Create('SaveTGA');
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   //prepare header
   FillChar(Header{%H-}, SizeOf(Header), 0);
@@ -7336,7 +7335,7 @@ var
   FormatDesc: TFormatDescriptor;
 begin
   if not (ftDDS in FormatGetSupportedFiles(Format)) then
-    raise EglBitmapUnsupportedFormat.Create('SaveDDS');
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   FormatDesc := TFormatDescriptor.Get(Format);
 
@@ -7479,7 +7478,7 @@ var
 begin
   FormatDesc := TFormatDescriptor.Get(Format);
   if FormatDesc.IsCompressed then
-    raise EglBitmapUnsupportedFormat.Create('TglBitmap2D.GrabScreen');
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   w    := aRight  - aLeft;
   h    := aBottom - aTop;
@@ -7729,10 +7728,8 @@ var
   end;
 
 begin
-  (* TODO Compression
-  if not FormatIsUncompressed(InternalFormat) then
-    raise EglBitmapUnsupportedFormatFormat.Create('TglBitmap2D.ToNormalMap - ' + UNSUPPORTED_FORMAT);
-    *)
+  if TFormatDescriptor.Get(Format).IsCompressed then
+    raise EglBitmapUnsupportedFormat.Create(Format);
 
   if aScale > 100 then
     Rec.Scale := 100