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raze-gles/source/common/textures/formats/ddstexture.cpp
Christoph Oelckers da26d1cec4 - more trivial adjustments.
2020-05-24 00:38:10 +02:00

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/*
** ddstexture.cpp
** Texture class for DDS images
**
**---------------------------------------------------------------------------
** Copyright 2006-2016 Randy Heit
** Copyright 2006-2019 Christoph Oelckers
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
** DDS is short for "DirectDraw Surface" and is essentially that. It's
** interesting to us because it is a standard file format for DXTC/S3TC
** encoded images. Look up "DDS File Reference" in the DirectX SDK or
** the online MSDN documentation to the specs for this file format. Look up
** "Compressed Texture Resources" for information about DXTC encoding.
**
** Perhaps the most important part of DXTC to realize is that every 4x4
** pixel block can only have four different colors, and only two of those
** are discrete. So depending on the texture, there may be very noticable
** quality degradation, or it may look virtually indistinguishable from
** the uncompressed texture.
**
** Note: Although this class supports reading RGB textures from a DDS,
** DO NOT use DDS images with plain RGB data. PNG does everything useful
** better. Since DDS lets the R, G, B, and A components lie anywhere in
** the pixel data, it is fairly inefficient to process.
*/
#include "files.h"
#include "filesystem.h"
#include "bitmap.h"
#include "imagehelpers.h"
#include "image.h"
// Since we want this to compile under Linux too, we need to define this
// stuff ourselves instead of including a DirectX header.
enum
{
ID_DDS = MAKE_ID('D', 'D', 'S', ' '),
ID_DXT1 = MAKE_ID('D', 'X', 'T', '1'),
ID_DXT2 = MAKE_ID('D', 'X', 'T', '2'),
ID_DXT3 = MAKE_ID('D', 'X', 'T', '3'),
ID_DXT4 = MAKE_ID('D', 'X', 'T', '4'),
ID_DXT5 = MAKE_ID('D', 'X', 'T', '5'),
// Bits in dwFlags
DDSD_CAPS = 0x00000001,
DDSD_HEIGHT = 0x00000002,
DDSD_WIDTH = 0x00000004,
DDSD_PITCH = 0x00000008,
DDSD_PIXELFORMAT = 0x00001000,
DDSD_MIPMAPCOUNT = 0x00020000,
DDSD_LINEARSIZE = 0x00080000,
DDSD_DEPTH = 0x00800000,
// Bits in ddpfPixelFormat
DDPF_ALPHAPIXELS = 0x00000001,
DDPF_FOURCC = 0x00000004,
DDPF_RGB = 0x00000040,
// Bits in DDSCAPS2.dwCaps1
DDSCAPS_COMPLEX = 0x00000008,
DDSCAPS_TEXTURE = 0x00001000,
DDSCAPS_MIPMAP = 0x00400000,
// Bits in DDSCAPS2.dwCaps2
DDSCAPS2_CUBEMAP = 0x00000200,
DDSCAPS2_CUBEMAP_POSITIVEX = 0x00000400,
DDSCAPS2_CUBEMAP_NEGATIVEX = 0x00000800,
DDSCAPS2_CUBEMAP_POSITIVEY = 0x00001000,
DDSCAPS2_CUBEMAP_NEGATIVEY = 0x00002000,
DDSCAPS2_CUBEMAP_POSITIVEZ = 0x00004000,
DDSCAPS2_CUBEMAP_NEGATIZEZ = 0x00008000,
DDSCAPS2_VOLUME = 0x00200000,
};
//==========================================================================
//
//
//
//==========================================================================
struct DDPIXELFORMAT
{
uint32_t Size; // Must be 32
uint32_t Flags;
uint32_t FourCC;
uint32_t RGBBitCount;
uint32_t RBitMask, GBitMask, BBitMask;
uint32_t RGBAlphaBitMask;
};
struct DDCAPS2
{
uint32_t Caps1, Caps2;
uint32_t Reserved[2];
};
struct DDSURFACEDESC2
{
uint32_t Size; // Must be 124. DevIL claims some writers set it to 'DDS ' instead.
uint32_t Flags;
uint32_t Height;
uint32_t Width;
union
{
int32_t Pitch;
uint32_t LinearSize;
};
uint32_t Depth;
uint32_t MipMapCount;
uint32_t Reserved1[11];
DDPIXELFORMAT PixelFormat;
DDCAPS2 Caps;
uint32_t Reserved2;
};
struct DDSFileHeader
{
uint32_t Magic;
DDSURFACEDESC2 Desc;
};
//==========================================================================
//
// A DDS image, with DXTx compression
//
//==========================================================================
class FDDSTexture : public FImageSource
{
enum
{
PIX_Palette = 0,
PIX_Alphatex = 1,
PIX_ARGB = 2
};
public:
FDDSTexture (FileReader &lump, int lumpnum, void *surfdesc);
TArray<uint8_t> CreatePalettedPixels(int conversion) override;
protected:
uint32_t Format;
uint32_t RMask, GMask, BMask, AMask;
uint8_t RShiftL, GShiftL, BShiftL, AShiftL;
uint8_t RShiftR, GShiftR, BShiftR, AShiftR;
int32_t Pitch;
uint32_t LinearSize;
static void CalcBitShift (uint32_t mask, uint8_t *lshift, uint8_t *rshift);
void ReadRGB (FileReader &lump, uint8_t *buffer, int pixelmode);
void DecompressDXT1 (FileReader &lump, uint8_t *buffer, int pixelmode);
void DecompressDXT3 (FileReader &lump, bool premultiplied, uint8_t *buffer, int pixelmode);
void DecompressDXT5 (FileReader &lump, bool premultiplied, uint8_t *buffer, int pixelmode);
int CopyPixels(FBitmap *bmp, int conversion) override;
friend class FTexture;
};
//==========================================================================
//
//
//
//==========================================================================
static bool CheckDDS (FileReader &file)
{
DDSFileHeader Header;
file.Seek(0, FileReader::SeekSet);
if (file.Read (&Header, sizeof(Header)) != sizeof(Header))
{
return false;
}
return Header.Magic == ID_DDS &&
(LittleLong(Header.Desc.Size) == sizeof(DDSURFACEDESC2) || Header.Desc.Size == ID_DDS) &&
LittleLong(Header.Desc.PixelFormat.Size) == sizeof(DDPIXELFORMAT) &&
(LittleLong(Header.Desc.Flags) & (DDSD_CAPS | DDSD_PIXELFORMAT | DDSD_WIDTH | DDSD_HEIGHT)) == (DDSD_CAPS | DDSD_PIXELFORMAT | DDSD_WIDTH | DDSD_HEIGHT) &&
Header.Desc.Width != 0 &&
Header.Desc.Height != 0;
}
//==========================================================================
//
//
//
//==========================================================================
FImageSource *DDSImage_TryCreate (FileReader &data, int lumpnum)
{
union
{
DDSURFACEDESC2 surfdesc;
uint32_t byteswapping[sizeof(DDSURFACEDESC2) / 4];
};
if (!CheckDDS(data)) return NULL;
data.Seek(4, FileReader::SeekSet);
data.Read (&surfdesc, sizeof(surfdesc));
#ifdef __BIG_ENDIAN__
// Every single element of the header is a uint32_t
for (unsigned int i = 0; i < sizeof(DDSURFACEDESC2) / 4; ++i)
{
byteswapping[i] = LittleLong(byteswapping[i]);
}
// Undo the byte swap for the pixel format
surfdesc.PixelFormat.FourCC = LittleLong(surfdesc.PixelFormat.FourCC);
#endif
if (surfdesc.PixelFormat.Flags & DDPF_FOURCC)
{
// Check for supported FourCC
if (surfdesc.PixelFormat.FourCC != ID_DXT1 &&
surfdesc.PixelFormat.FourCC != ID_DXT2 &&
surfdesc.PixelFormat.FourCC != ID_DXT3 &&
surfdesc.PixelFormat.FourCC != ID_DXT4 &&
surfdesc.PixelFormat.FourCC != ID_DXT5)
{
return NULL;
}
if (!(surfdesc.Flags & DDSD_LINEARSIZE))
{
return NULL;
}
}
else if (surfdesc.PixelFormat.Flags & DDPF_RGB)
{
if ((surfdesc.PixelFormat.RGBBitCount >> 3) < 1 ||
(surfdesc.PixelFormat.RGBBitCount >> 3) > 4)
{
return NULL;
}
if ((surfdesc.Flags & DDSD_PITCH) && (surfdesc.Pitch <= 0))
{
return NULL;
}
}
else
{
return NULL;
}
return new FDDSTexture (data, lumpnum, &surfdesc);
}
//==========================================================================
//
//
//
//==========================================================================
FDDSTexture::FDDSTexture (FileReader &lump, int lumpnum, void *vsurfdesc)
: FImageSource(lumpnum)
{
DDSURFACEDESC2 *surf = (DDSURFACEDESC2 *)vsurfdesc;
bMasked = false;
Width = uint16_t(surf->Width);
Height = uint16_t(surf->Height);
if (surf->PixelFormat.Flags & DDPF_FOURCC)
{
Format = surf->PixelFormat.FourCC;
Pitch = 0;
LinearSize = surf->LinearSize;
}
else // DDPF_RGB
{
Format = surf->PixelFormat.RGBBitCount >> 3;
CalcBitShift (RMask = surf->PixelFormat.RBitMask, &RShiftL, &RShiftR);
CalcBitShift (GMask = surf->PixelFormat.GBitMask, &GShiftL, &GShiftR);
CalcBitShift (BMask = surf->PixelFormat.BBitMask, &BShiftL, &BShiftR);
if (surf->PixelFormat.Flags & DDPF_ALPHAPIXELS)
{
CalcBitShift (AMask = surf->PixelFormat.RGBAlphaBitMask, &AShiftL, &AShiftR);
}
else
{
AMask = 0;
AShiftL = AShiftR = 0;
}
if (surf->Flags & DDSD_PITCH)
{
Pitch = surf->Pitch;
}
else
{
Pitch = (Width * Format + 3) & ~3;
}
LinearSize = Pitch * Height;
}
}
//==========================================================================
//
// Returns the number of bits the color must be shifted to produce
// an 8-bit value, as in:
//
// c = (color & mask) << lshift;
// c |= c >> rshift;
// c >>= 24;
//
// For any color of at least 4 bits, this ensures that the result
// of the calculation for c will be fully saturated, given a maximum
// value for the input bit mask.
//
//==========================================================================
void FDDSTexture::CalcBitShift (uint32_t mask, uint8_t *lshiftp, uint8_t *rshiftp)
{
uint8_t shift;
if (mask == 0)
{
*lshiftp = *rshiftp = 0;
return;
}
shift = 0;
while ((mask & 0x80000000) == 0)
{
mask <<= 1;
shift++;
}
*lshiftp = shift;
shift = 0;
while (mask & 0x80000000)
{
mask <<= 1;
shift++;
}
*rshiftp = shift;
}
//==========================================================================
//
//
//
//==========================================================================
TArray<uint8_t> FDDSTexture::CreatePalettedPixels(int conversion)
{
auto lump = fileSystem.OpenFileReader (SourceLump);
TArray<uint8_t> Pixels(Width*Height, true);
lump.Seek (sizeof(DDSURFACEDESC2) + 4, FileReader::SeekSet);
int pmode = conversion == luminance ? PIX_Alphatex : PIX_Palette;
if (Format >= 1 && Format <= 4) // RGB: Format is # of bytes per pixel
{
ReadRGB (lump, Pixels.Data(), pmode);
}
else if (Format == ID_DXT1)
{
DecompressDXT1 (lump, Pixels.Data(), pmode);
}
else if (Format == ID_DXT3 || Format == ID_DXT2)
{
DecompressDXT3 (lump, Format == ID_DXT2, Pixels.Data(), pmode);
}
else if (Format == ID_DXT5 || Format == ID_DXT4)
{
DecompressDXT5 (lump, Format == ID_DXT4, Pixels.Data(), pmode);
}
return Pixels;
}
//==========================================================================
//
// Note that pixel size == 8 is column-major, but 32 is row-major!
//
//==========================================================================
void FDDSTexture::ReadRGB (FileReader &lump, uint8_t *buffer, int pixelmode)
{
uint32_t x, y;
uint32_t amask = AMask == 0 ? 0 : 0x80000000 >> AShiftL;
uint8_t *linebuff = new uint8_t[Pitch];
for (y = Height; y > 0; --y)
{
uint8_t *buffp = linebuff;
uint8_t *pixelp = pixelmode == PIX_ARGB ? buffer + 4 * (y - 1)*Width : buffer + y - 1;
lump.Read (linebuff, Pitch);
for (x = Width; x > 0; --x)
{
uint32_t c;
if (Format == 4)
{
c = LittleLong(*(uint32_t *)buffp); buffp += 4;
}
else if (Format == 2)
{
c = LittleShort(*(uint16_t *)buffp); buffp += 2;
}
else if (Format == 3)
{
c = buffp[0] | (buffp[1] << 8) | (buffp[2] << 16); buffp += 3;
}
else // Format == 1
{
c = *buffp++;
}
if (pixelmode != PIX_ARGB)
{
if (amask == 0 || (c & amask))
{
uint32_t r = (c & RMask) << RShiftL; r |= r >> RShiftR;
uint32_t g = (c & GMask) << GShiftL; g |= g >> GShiftR;
uint32_t b = (c & BMask) << BShiftL; b |= b >> BShiftR;
uint32_t a = (c & AMask) << AShiftL; a |= a >> AShiftR;
*pixelp = ImageHelpers::RGBToPalette(pixelmode == PIX_Alphatex, r >> 24, g >> 24, b >> 24, a >> 24);
}
else
{
*pixelp = 0;
bMasked = true;
}
pixelp += Height;
}
else
{
uint32_t r = (c & RMask) << RShiftL; r |= r >> RShiftR;
uint32_t g = (c & GMask) << GShiftL; g |= g >> GShiftR;
uint32_t b = (c & BMask) << BShiftL; b |= b >> BShiftR;
uint32_t a = (c & AMask) << AShiftL; a |= a >> AShiftR;
pixelp[0] = (uint8_t)(b>>24);
pixelp[1] = (uint8_t)(g>>24);
pixelp[2] = (uint8_t)(r>>24);
pixelp[3] = (uint8_t)(a>>24);
pixelp+=4;
}
}
}
delete[] linebuff;
}
//==========================================================================
//
//
//
//==========================================================================
void FDDSTexture::DecompressDXT1 (FileReader &lump, uint8_t *buffer, int pixelmode)
{
const long blocklinelen = ((Width + 3) >> 2) << 3;
uint8_t *blockbuff = new uint8_t[blocklinelen];
uint8_t *block;
PalEntry color[4];
uint8_t palcol[4] = { 0,0,0,0 }; // shut up compiler warnings.
int ox, oy, x, y, i;
color[0].a = 255;
color[1].a = 255;
color[2].a = 255;
for (oy = 0; oy < Height; oy += 4)
{
lump.Read (blockbuff, blocklinelen);
block = blockbuff;
for (ox = 0; ox < Width; ox += 4)
{
uint16_t color16[2] = { LittleShort(((uint16_t *)block)[0]), LittleShort(((uint16_t *)block)[1]) };
// Convert color from R5G6B5 to R8G8B8.
for (i = 1; i >= 0; --i)
{
color[i].r = ((color16[i] & 0xF800) >> 8) | (color16[i] >> 13);
color[i].g = ((color16[i] & 0x07E0) >> 3) | ((color16[i] & 0x0600) >> 9);
color[i].b = ((color16[i] & 0x001F) << 3) | ((color16[i] & 0x001C) >> 2);
}
if (color16[0] > color16[1])
{ // Four-color block: derive the other two colors.
color[2].r = (color[0].r + color[0].r + color[1].r + 1) / 3;
color[2].g = (color[0].g + color[0].g + color[1].g + 1) / 3;
color[2].b = (color[0].b + color[0].b + color[1].b + 1) / 3;
color[3].r = (color[0].r + color[1].r + color[1].r + 1) / 3;
color[3].g = (color[0].g + color[1].g + color[1].g + 1) / 3;
color[3].b = (color[0].b + color[1].b + color[1].b + 1) / 3;
color[3].a = 255;
}
else
{ // Three-color block: derive the other color.
color[2].r = (color[0].r + color[1].r) / 2;
color[2].g = (color[0].g + color[1].g) / 2;
color[2].b = (color[0].b + color[1].b) / 2;
color[3].a = color[3].b = color[3].g = color[3].r = 0;
// If you have a three-color block, presumably that transparent
// color is going to be used.
bMasked = true;
}
// Pick colors from the palette for each of the four colors.
if (pixelmode != PIX_ARGB) for (i = 3; i >= 0; --i)
{
palcol[i] = ImageHelpers::RGBToPalette(pixelmode == PIX_Alphatex, color[i]);
}
// Now decode this 4x4 block to the pixel buffer.
for (y = 0; y < 4; ++y)
{
if (oy + y >= Height)
{
break;
}
uint8_t yslice = block[4 + y];
for (x = 0; x < 4; ++x)
{
if (ox + x >= Width)
{
break;
}
int ci = (yslice >> (x + x)) & 3;
if (pixelmode != PIX_ARGB)
{
buffer[oy + y + (ox + x) * Height] = palcol[ci];
}
else
{
uint8_t * tcp = &buffer[(ox + x)*4 + (oy + y) * Width*4];
tcp[0] = color[ci].b;
tcp[1] = color[ci].g;
tcp[2] = color[ci].r;
tcp[3] = color[ci].a;
}
}
}
block += 8;
}
}
delete[] blockbuff;
}
//==========================================================================
//
// DXT3: Decompression is identical to DXT1, except every 64-bit block is
// preceded by another 64-bit block with explicit alpha values.
//
//==========================================================================
void FDDSTexture::DecompressDXT3 (FileReader &lump, bool premultiplied, uint8_t *buffer, int pixelmode)
{
const long blocklinelen = ((Width + 3) >> 2) << 4;
uint8_t *blockbuff = new uint8_t[blocklinelen];
uint8_t *block;
PalEntry color[4];
uint8_t palcol[4] = { 0,0,0,0 };
int ox, oy, x, y, i;
for (oy = 0; oy < Height; oy += 4)
{
lump.Read (blockbuff, blocklinelen);
block = blockbuff;
for (ox = 0; ox < Width; ox += 4)
{
uint16_t color16[2] = { LittleShort(((uint16_t *)block)[4]), LittleShort(((uint16_t *)block)[5]) };
// Convert color from R5G6B5 to R8G8B8.
for (i = 1; i >= 0; --i)
{
color[i].r = ((color16[i] & 0xF800) >> 8) | (color16[i] >> 13);
color[i].g = ((color16[i] & 0x07E0) >> 3) | ((color16[i] & 0x0600) >> 9);
color[i].b = ((color16[i] & 0x001F) << 3) | ((color16[i] & 0x001C) >> 2);
}
// Derive the other two colors.
color[2].r = (color[0].r + color[0].r + color[1].r + 1) / 3;
color[2].g = (color[0].g + color[0].g + color[1].g + 1) / 3;
color[2].b = (color[0].b + color[0].b + color[1].b + 1) / 3;
color[3].r = (color[0].r + color[1].r + color[1].r + 1) / 3;
color[3].g = (color[0].g + color[1].g + color[1].g + 1) / 3;
color[3].b = (color[0].b + color[1].b + color[1].b + 1) / 3;
// Pick colors from the palette for each of the four colors.
if (pixelmode != PIX_ARGB) for (i = 3; i >= 0; --i)
{
palcol[i] = ImageHelpers::RGBToPalette(pixelmode == PIX_Alphatex, color[i], false);
}
// Now decode this 4x4 block to the pixel buffer.
for (y = 0; y < 4; ++y)
{
if (oy + y >= Height)
{
break;
}
uint8_t yslice = block[12 + y];
uint16_t yalphaslice = LittleShort(((uint16_t *)block)[y]);
for (x = 0; x < 4; ++x)
{
if (ox + x >= Width)
{
break;
}
if (pixelmode == PIX_Palette)
{
buffer[oy + y + (ox + x) * Height] = ((yalphaslice >> (x*4)) & 15) < 8 ?
(bMasked = true, 0) : palcol[(yslice >> (x + x)) & 3];
}
else if (pixelmode == PIX_Alphatex)
{
int alphaval = ((yalphaslice >> (x * 4)) & 15);
int palval = palcol[(yslice >> (x + x)) & 3];
buffer[oy + y + (ox + x) * Height] = palval * alphaval / 15;
}
else
{
uint8_t * tcp = &buffer[(ox + x)*4 + (oy + y) * Width*4];
int c = (yslice >> (x + x)) & 3;
tcp[0] = color[c].b;
tcp[1] = color[c].g;
tcp[2] = color[c].r;
tcp[3] = ((yalphaslice >> (x * 4)) & 15) * 0x11;
}
}
}
block += 16;
}
}
delete[] blockbuff;
}
//==========================================================================
//
// DXT5: Decompression is identical to DXT3, except every 64-bit alpha block
// contains interpolated alpha values, similar to the 64-bit color block.
//
//==========================================================================
void FDDSTexture::DecompressDXT5 (FileReader &lump, bool premultiplied, uint8_t *buffer, int pixelmode)
{
const long blocklinelen = ((Width + 3) >> 2) << 4;
uint8_t *blockbuff = new uint8_t[blocklinelen];
uint8_t *block;
PalEntry color[4];
uint8_t palcol[4] = { 0,0,0,0 };
uint32_t yalphaslice = 0;
int ox, oy, x, y, i;
for (oy = 0; oy < Height; oy += 4)
{
lump.Read (blockbuff, blocklinelen);
block = blockbuff;
for (ox = 0; ox < Width; ox += 4)
{
uint16_t color16[2] = { LittleShort(((uint16_t *)block)[4]), LittleShort(((uint16_t *)block)[5]) };
uint8_t alpha[8];
// Calculate the eight alpha values.
alpha[0] = block[0];
alpha[1] = block[1];
if (alpha[0] >= alpha[1])
{ // Eight-alpha block: derive the other six alphas.
for (i = 0; i < 6; ++i)
{
alpha[i + 2] = ((6 - i) * alpha[0] + (i + 1) * alpha[1] + 3) / 7;
}
}
else
{ // Six-alpha block: derive the other four alphas.
for (i = 0; i < 4; ++i)
{
alpha[i + 2] = ((4 - i) * alpha[0] + (i + 1) * alpha[1] + 2) / 5;
}
alpha[6] = 0;
alpha[7] = 255;
}
// Convert color from R5G6B5 to R8G8B8.
for (i = 1; i >= 0; --i)
{
color[i].r = ((color16[i] & 0xF800) >> 8) | (color16[i] >> 13);
color[i].g = ((color16[i] & 0x07E0) >> 3) | ((color16[i] & 0x0600) >> 9);
color[i].b = ((color16[i] & 0x001F) << 3) | ((color16[i] & 0x001C) >> 2);
}
// Derive the other two colors.
color[2].r = (color[0].r + color[0].r + color[1].r + 1) / 3;
color[2].g = (color[0].g + color[0].g + color[1].g + 1) / 3;
color[2].b = (color[0].b + color[0].b + color[1].b + 1) / 3;
color[3].r = (color[0].r + color[1].r + color[1].r + 1) / 3;
color[3].g = (color[0].g + color[1].g + color[1].g + 1) / 3;
color[3].b = (color[0].b + color[1].b + color[1].b + 1) / 3;
// Pick colors from the palette for each of the four colors.
if (pixelmode != PIX_ARGB) for (i = 3; i >= 0; --i)
{
palcol[i] = ImageHelpers::RGBToPalette(pixelmode == PIX_Alphatex, color[i], false);
}
// Now decode this 4x4 block to the pixel buffer.
for (y = 0; y < 4; ++y)
{
if (oy + y >= Height)
{
break;
}
// Alpha values are stored in 3 bytes for 2 rows
if ((y & 1) == 0)
{
yalphaslice = block[y*3] | (block[y*3+1] << 8) | (block[y*3+2] << 16);
}
else
{
yalphaslice >>= 12;
}
uint8_t yslice = block[12 + y];
for (x = 0; x < 4; ++x)
{
if (ox + x >= Width)
{
break;
}
if (pixelmode == PIX_Palette)
{
buffer[oy + y + (ox + x) * Height] = alpha[((yalphaslice >> (x*3)) & 7)] < 128 ?
(bMasked = true, 0) : palcol[(yslice >> (x + x)) & 3];
}
else if (pixelmode == PIX_Alphatex)
{
int alphaval = alpha[((yalphaslice >> (x * 3)) & 7)];
int palval = palcol[(yslice >> (x + x)) & 3];
buffer[oy + y + (ox + x) * Height] = palval * alphaval / 255;
}
else
{
uint8_t * tcp = &buffer[(ox + x)*4 + (oy + y) * Width*4];
int c = (yslice >> (x + x)) & 3;
tcp[0] = color[c].b;
tcp[1] = color[c].g;
tcp[2] = color[c].r;
tcp[3] = alpha[((yalphaslice >> (x*3)) & 7)];
}
}
}
block += 16;
}
}
delete[] blockbuff;
}
//===========================================================================
//
// FDDSTexture::CopyPixels
//
//===========================================================================
int FDDSTexture::CopyPixels(FBitmap *bmp, int conversion)
{
auto lump = fileSystem.OpenFileReader (SourceLump);
uint8_t *TexBuffer = bmp->GetPixels();
lump.Seek (sizeof(DDSURFACEDESC2) + 4, FileReader::SeekSet);
if (Format >= 1 && Format <= 4) // RGB: Format is # of bytes per pixel
{
ReadRGB (lump, TexBuffer, PIX_ARGB);
}
else if (Format == ID_DXT1)
{
DecompressDXT1 (lump, TexBuffer, PIX_ARGB);
}
else if (Format == ID_DXT3 || Format == ID_DXT2)
{
DecompressDXT3 (lump, Format == ID_DXT2, TexBuffer, PIX_ARGB);
}
else if (Format == ID_DXT5 || Format == ID_DXT4)
{
DecompressDXT5 (lump, Format == ID_DXT4, TexBuffer, PIX_ARGB);
}
return -1;
}
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