OrdinaryMagician/vkdoom_m
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Fix some rare PNG tRNS chunk cases

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- For grayscale images drawn with the paletted renderer, the value here
  was treated as always full range [0,65535]. The max value is actually
  determined by the bit depth.
- For RGB images drawn with the paletted renderer, the tRNS chunk was
  ignored.
- For grayscale images drawn with the RGB renderer, having a tRNS chunk
  present resulted in undefined behavior.
- For RGB images drawn with the RGB renderer, the tRNS chunk was ignored.
This commit is contained in:
Randy Heit 2016-01-25 21:23:53 -06:00
commit 0fc40cff0a
3 changed files with 90 additions and 34 deletions
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64
src/textures/pngtexture.cpp
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@ -70,6 +70,8 @@ protected:
BYTE BitDepth;
BYTE ColorType;
BYTE Interlace;
bool HaveTrans;
WORD NonPaletteTrans[3];
BYTE *PaletteMap;
int PaletteSize;
@ -195,7 +197,7 @@ FTexture *PNGTexture_CreateFromFile(PNGHandle *png, const FString &filename)
FPNGTexture::FPNGTexture (FileReader &lump, int lumpnum, const FString &filename, int width, int height,
BYTE depth, BYTE colortype, BYTE interlace)
: FTexture(NULL, lumpnum), SourceFile(filename), Pixels(0), Spans(0),
BitDepth(depth), ColorType(colortype), Interlace(interlace),
BitDepth(depth), ColorType(colortype), Interlace(interlace), HaveTrans(false),
PaletteMap(0), PaletteSize(0), StartOfIDAT(0)
{
union
@ -204,7 +206,6 @@ FPNGTexture::FPNGTexture (FileReader &lump, int lumpnum, const FString &filename
BYTE pngpal[256][3];
} p;
BYTE trans[256];
bool havetRNS = false;
DWORD len, id;
int i;
@ -273,7 +274,11 @@ FPNGTexture::FPNGTexture (FileReader &lump, int lumpnum, const FString &filename
case MAKE_ID('t','R','N','S'):
lump.Read (trans, len);
havetRNS = true;
HaveTrans = true;
// Save for colortype 2
NonPaletteTrans[0] = BigShort(((WORD *)trans)[0]);
NonPaletteTrans[1] = BigShort(((WORD *)trans)[1]);
NonPaletteTrans[2] = BigShort(((WORD *)trans)[2]);
break;
case MAKE_ID('a','l','P','h'):
@ -297,13 +302,13 @@ FPNGTexture::FPNGTexture (FileReader &lump, int lumpnum, const FString &filename
case 0: // Grayscale
if (!bAlphaTexture)
{
if (colortype == 0 && havetRNS && trans[0] != 0)
if (colortype == 0 && HaveTrans && NonPaletteTrans[0] != 0 && NonPaletteTrans[0] < 256)
{
bMasked = true;
PaletteSize = 256;
PaletteMap = new BYTE[256];
memcpy (PaletteMap, GrayMap, 256);
PaletteMap[trans[0]] = 0;
PaletteMap[NonPaletteTrans[0]] = 0;
}
else
{
@ -328,6 +333,10 @@ FPNGTexture::FPNGTexture (FileReader &lump, int lumpnum, const FString &filename
case 6: // RGB + Alpha
bMasked = true;
break;
case 2: // RGB
bMasked = HaveTrans;
break;
}
}
@ -521,7 +530,23 @@ void FPNGTexture::MakeTexture ()
{
for (y = Height; y > 0; --y)
{
*out++ = RGB32k.RGB[in[0]>>3][in[1]>>3][in[2]>>3];
if (!HaveTrans)
{
*out++ = RGB32k.RGB[in[0]>>3][in[1]>>3][in[2]>>3];
}
else
{
if (in[0] == NonPaletteTrans[0] &&
in[1] == NonPaletteTrans[1] &&
in[2] == NonPaletteTrans[2])
{
*out++ = 0;
}
else
{
*out++ = RGB32k.RGB[in[0]>>3][in[1]>>3][in[2]>>3];
}
}
in += pitch;
}
in -= backstep;
@ -625,11 +650,14 @@ int FPNGTexture::CopyTrueColorPixels(FBitmap *bmp, int x, int y, int rotate, FCo
break;
case MAKE_ID('t','R','N','S'):
for(DWORD i = 0; i < len; i++)
if (ColorType == 3)
{
(*lump) >> pe[i].a;
if (pe[i].a != 0 && pe[i].a != 255)
transpal = true;
for(DWORD i = 0; i < len; i++)
{
(*lump) >> pe[i].a;
if (pe[i].a != 0 && pe[i].a != 255)
transpal = true;
}
}
break;
}
@ -639,6 +667,12 @@ int FPNGTexture::CopyTrueColorPixels(FBitmap *bmp, int x, int y, int rotate, FCo
lump->Read(&id, 4);
}
if (ColorType == 0 && HaveTrans && NonPaletteTrans[0] < 256)
{
pe[NonPaletteTrans[0]].a = 0;
transpal = true;
}
BYTE * Pixels = new BYTE[pixwidth * Height];
lump->Seek (StartOfIDAT, SEEK_SET);
@ -655,7 +689,15 @@ int FPNGTexture::CopyTrueColorPixels(FBitmap *bmp, int x, int y, int rotate, FCo
break;
case 2:
bmp->CopyPixelDataRGB(x, y, Pixels, Width, Height, 3, pixwidth, rotate, CF_RGB, inf);
if (!HaveTrans)
{
bmp->CopyPixelDataRGB(x, y, Pixels, Width, Height, 3, pixwidth, rotate, CF_RGB, inf);
}
else
{
bmp->CopyPixelDataRGB(x, y, Pixels, Width, Height, 3, pixwidth, rotate, CF_RGBT, inf,
NonPaletteTrans[0], NonPaletteTrans[1], NonPaletteTrans[2]);
}
break;
case 4: