private static Color8888 DxtcRead3bColor(ushort data)
{
byte r = unchecked ((byte)(data & 0x1F));
byte g = unchecked ((byte)((data & 0x7E0) >> 5));
byte b = unchecked ((byte)((data & 0xF800) >> 11));
Color8888 op = default;
op.Red = unchecked ((byte)(r << 3 | r >> 2));
op.Green = unchecked ((byte)(g << 2 | g >> 3));
op.Blue = unchecked ((byte)(b << 3 | r >> 2));
op.Alpha = 0xFF;
return(op);
}
private static Color8888 DxtcRead2bColor(BinaryReader reader)
{
byte data0 = reader.ReadByte();
byte data1 = reader.ReadByte();
byte r = unchecked ((byte)(data0 & 0x1F));
byte g = unchecked ((byte)(((data0 & 0xE0) >> 5) | ((data1 & 0x7) << 3)));
byte b = unchecked ((byte)((data1 & 0xF8) >> 3));
Color8888 op = default;
op.Red = unchecked ((byte)(r << 3 | r >> 2));
op.Green = unchecked ((byte)(g << 2 | g >> 3));
op.Blue = unchecked ((byte)(b << 3 | b >> 2));
return(op);
}
public static void DecompressDXT1(BinaryReader sourceReader, Stream destination, DDSContainerParameters @params)
{
int depth = @params.BitMapDepth;
int width = @params.Width;
int height = @params.Height;
int bpp = GetRGBABytesPerPixel(@params);
int bpc = GetBytesPerColor(@params);
int bps = width * bpp * bpc;
long sizeOfPlane = bps * height;
Color8888[] colors = new Color8888[4];
long position = destination.Position;
for (int z = 0; z < depth; z++)
{
// mirror Y
for (int y = height - 1; y >= 0; y -= 4)
{
for (int x = 0; x < width; x += 4)
{
ushort color0 = sourceReader.ReadUInt16();
ushort color1 = sourceReader.ReadUInt16();
uint bitMask0 = sourceReader.ReadUInt16();
uint bitMask1 = sourceReader.ReadUInt16();
uint bitMask = (bitMask0 << 0) | (bitMask1 << 16);
colors[0] = DxtcRead3bColor(color0);
colors[1] = DxtcRead3bColor(color1);
if (color0 > color1)
{
// Four-color block: derive the other two colors.
// 00 = color_0, 01 = color_1, 10 = color_2, 11 = color_3
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colors[2].Blue = unchecked ((byte)((2 * colors[0].Blue + colors[1].Blue + 1) / 3));
colors[2].Green = unchecked ((byte)((2 * colors[0].Green + colors[1].Green + 1) / 3));
colors[2].Red = unchecked ((byte)((2 * colors[0].Red + colors[1].Red + 1) / 3));
colors[2].Alpha = 0xFF;
colors[3].Alpha = 0xFF;
}
else
{
// Three-color block: derive the other color.
// 00 = color_0, 01 = color_1, 10 = color_2,
// 11 = transparent.
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colors[2].Blue = unchecked ((byte)((colors[0].Blue + colors[1].Blue) / 2));
colors[2].Green = unchecked ((byte)((colors[0].Green + colors[1].Green) / 2));
colors[2].Red = unchecked ((byte)((colors[0].Red + colors[1].Red) / 2));
colors[2].Alpha = 0xFF;
colors[3].Alpha = 0x0;
}
colors[3].Blue = unchecked ((byte)((colors[0].Blue + 2 * colors[1].Blue + 1) / 3));
colors[3].Green = unchecked ((byte)((colors[0].Green + 2 * colors[1].Green + 1) / 3));
colors[3].Red = unchecked ((byte)((colors[0].Red + 2 * colors[1].Red + 1) / 3));
int bitIndex = 0;
for (int ly = 0; ly < 4; ly++)
{
for (int lx = 0; lx < 4; lx++, bitIndex++)
{
int colorIndex = unchecked ((int)((bitMask & (3 << bitIndex * 2)) >> bitIndex * 2));
Color8888 color = colors[colorIndex];
if ((x + lx) < width && (y - ly) < height && (y - ly) >= 0)
{
// mirror Y
long offset = z * sizeOfPlane + (y - ly) * bps + (x + lx) * bpp;
destination.Position = position + offset;
destination.WriteByte(color.Red);
destination.WriteByte(color.Green);
destination.WriteByte(color.Blue);
destination.WriteByte(color.Alpha);
}
}
}
}
}
}
}
public static void DecompressDXT5(BinaryReader sourceReader, Stream destination, DDSContainerParameters @params)
{
int depth = @params.BitMapDepth;
int width = @params.Width;
int height = @params.Height;
int bpp = GetRGBABytesPerPixel(@params);
int bpc = GetBytesPerColor(@params);
int bps = width * bpp * bpc;
long sizeOfPlane = bps * height;
Color8888[] colors = new Color8888[4];
ushort[] alphas = new ushort[8];
byte[] alphaMask = new byte[6];
long position = destination.Position;
for (int z = 0; z < depth; z++)
{
// mirror Y
for (int y = height - 1; y >= 0; y -= 4)
{
for (int x = 0; x < width; x += 4)
{
ushort alpha = sourceReader.ReadUInt16();
alphas[0] = unchecked ((byte)(alpha >> 0));
alphas[1] = unchecked ((byte)(alpha >> 8));
ushort alphaMask0 = sourceReader.ReadUInt16();
ushort alphaMask1 = sourceReader.ReadUInt16();
ushort alphaMask2 = sourceReader.ReadUInt16();
alphaMask[0] = unchecked ((byte)(alphaMask0 >> 0));
alphaMask[1] = unchecked ((byte)(alphaMask0 >> 8));
alphaMask[2] = unchecked ((byte)(alphaMask1 >> 0));
alphaMask[3] = unchecked ((byte)(alphaMask1 >> 8));
alphaMask[4] = unchecked ((byte)(alphaMask2 >> 0));
alphaMask[5] = unchecked ((byte)(alphaMask2 >> 8));
colors[0] = DxtcRead2bColor(sourceReader);
colors[1] = DxtcRead2bColor(sourceReader);
uint bitMask0 = sourceReader.ReadUInt16();
uint bitMask1 = sourceReader.ReadUInt16();
uint bitMask = (bitMask0 << 0) | (bitMask1 << 16);
// Four-color block: derive the other two colors.
// 00 = color_0, 01 = color_1, 10 = color_2, 11 = color_3
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colors[2].Blue = unchecked ((byte)((2 * colors[0].Blue + colors[1].Blue + 1) / 3));
colors[2].Green = unchecked ((byte)((2 * colors[0].Green + colors[1].Green + 1) / 3));
colors[2].Red = unchecked ((byte)((2 * colors[0].Red + colors[1].Red + 1) / 3));
colors[3].Blue = unchecked ((byte)((colors[0].Blue + 2 * colors[1].Blue + 1) / 3));
colors[3].Green = unchecked ((byte)((colors[0].Green + 2 * colors[1].Green + 1) / 3));
colors[3].Red = unchecked ((byte)((colors[0].Red + 2 * colors[1].Red + 1) / 3));
int bitIndex = 0;
for (int ly = 0; ly < 4; ly++)
{
for (int lx = 0; lx < 4; lx++, bitIndex++)
{
int colorIndex = (int)((bitMask & (0x03 << bitIndex * 2)) >> bitIndex * 2);
Color8888 col = colors[colorIndex];
// only put pixels out < width or height
if ((x + lx) < width && (y - ly) < height && (y - ly) >= 0)
{
// mirror Y
long offset = z * sizeOfPlane + (y - ly) * bps + (x + lx) * bpp;
destination.Position = position + offset;
destination.WriteByte(col.Red);
destination.WriteByte(col.Green);
destination.WriteByte(col.Blue);
}
}
}
// 8-alpha or 6-alpha block?
if (alphas[0] > alphas[1])
{
// 8-alpha block: derive the other six alphas.
// Bit code 000 = alpha_0, 001 = alpha_1, others are interpolated.
alphas[2] = unchecked ((ushort)((6 * alphas[0] + 1 * alphas[1] + 3) / 7)); // bit code 010
alphas[3] = unchecked ((ushort)((5 * alphas[0] + 2 * alphas[1] + 3) / 7)); // bit code 011
alphas[4] = unchecked ((ushort)((4 * alphas[0] + 3 * alphas[1] + 3) / 7)); // bit code 100
alphas[5] = unchecked ((ushort)((3 * alphas[0] + 4 * alphas[1] + 3) / 7)); // bit code 101
alphas[6] = unchecked ((ushort)((2 * alphas[0] + 5 * alphas[1] + 3) / 7)); // bit code 110
alphas[7] = unchecked ((ushort)((1 * alphas[0] + 6 * alphas[1] + 3) / 7)); // bit code 111
}
else
{
// 6-alpha block.
// Bit code 000 = alpha_0, 001 = alpha_1, others are interpolated.
alphas[2] = unchecked ((ushort)((4 * alphas[0] + 1 * alphas[1] + 2) / 5)); // Bit code 010
alphas[3] = unchecked ((ushort)((3 * alphas[0] + 2 * alphas[1] + 2) / 5)); // Bit code 011
alphas[4] = unchecked ((ushort)((2 * alphas[0] + 3 * alphas[1] + 2) / 5)); // Bit code 100
alphas[5] = unchecked ((ushort)((1 * alphas[0] + 4 * alphas[1] + 2) / 5)); // Bit code 101
alphas[6] = 0x00; // Bit code 110
alphas[7] = 0xFF; // Bit code 111
}
// Note: Have to separate the next two loops,
// it operates on a 6-byte system.
// First three bytes
//uint bits = (uint)(alphamask[0]);
uint bits = unchecked ((uint)((alphaMask[0]) | (alphaMask[1] << 8) | (alphaMask[2] << 16)));
for (int ly = 0; ly < 2; ly++)
{
for (int lx = 0; lx < 4; lx++, bits >>= 3)
{
// only put pixels out < width or height
if ((x + lx) < width && (y - ly) < height && (y - ly) >= 0)
{
byte alphaValue = unchecked ((byte)alphas[bits & 0x07]);
// mirror Y
long offset = z * sizeOfPlane + (y - ly) * bps + (x + lx) * bpp + 3;
destination.Position = position + offset;
destination.WriteByte(alphaValue);
}
}
}
// Last three bytes
//bits = (uint)(alphamask[3]);
bits = unchecked ((uint)((alphaMask[3]) | (alphaMask[4] << 8) | (alphaMask[5] << 16)));
for (int ly = 2; ly < 4; ly++)
{
for (int lx = 0; lx < 4; lx++, bits >>= 3)
{
// only put pixels out < width or height
if ((x + lx) < width && (y - ly) < height && (y - ly) >= 0)
{
byte alphaValue = unchecked ((byte)alphas[bits & 0x07]);
// mirror Y
long offset = z * sizeOfPlane + (y - ly) * bps + (x + lx) * bpp + 3;
destination.Position = position + offset;
destination.WriteByte(alphaValue);
}
}
}
}
}
}
}
public static void DecompressDXT3(Stream destination, Stream source, DDSConvertParameters @params)
{
int depth = @params.BitMapDepth;
int width = @params.Width;
int height = @params.Height;
int bpp = GetRGBABytesPerPixel(@params);
int bpc = GetBytesPerColor(@params);
int bps = width * bpp * bpc;
long sizeOfPlane = bps * height;
Color8888[] colors = new Color8888[4];
byte[] alphas = new byte[16];
long position = destination.Position;
using (BinaryReader reader = new BinaryReader(source, Encoding.UTF8, true))
{
for (int z = 0; z < depth; z++)
{
// mirror Y
for (int y = height - 1; y >= 0; y -= 4)
{
for (int x = 0; x < width; x += 4)
{
for (int i = 0; i < 4; ++i)
{
ushort alpha = reader.ReadUInt16();
alphas[i * 4 + 0] = (byte)(((alpha >> 0) & 0xF) * 0x11);
alphas[i * 4 + 1] = (byte)(((alpha >> 4) & 0xF) * 0x11);
alphas[i * 4 + 2] = (byte)(((alpha >> 8) & 0xF) * 0x11);
alphas[i * 4 + 3] = (byte)(((alpha >> 12) & 0xF) * 0x11);
}
ushort color0 = reader.ReadUInt16();
ushort color1 = reader.ReadUInt16();
uint bitMask = reader.ReadUInt32();
colors[0] = DxtcRead3bColor(color0);
colors[1] = DxtcRead3bColor(color1);
if (color0 > color1)
{
// Four-color block: derive the other two colors.
// 00 = color_0, 01 = color_1, 10 = color_2, 11 = color_3
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colors[2].Blue = unchecked ((byte)((2 * colors[0].Blue + colors[1].Blue + 1) / 3));
colors[2].Green = unchecked ((byte)((2 * colors[0].Green + colors[1].Green + 1) / 3));
colors[2].Red = unchecked ((byte)((2 * colors[0].Red + colors[1].Red + 1) / 3));
}
else
{
// Three-color block: derive the other color.
// 00 = color_0, 01 = color_1, 10 = color_2,
// 11 = transparent.
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colors[2].Blue = unchecked ((byte)((colors[0].Blue + colors[1].Blue) / 2));
colors[2].Green = unchecked ((byte)((colors[0].Green + colors[1].Green) / 2));
colors[2].Red = unchecked ((byte)((colors[0].Red + colors[1].Red) / 2));
}
colors[3].Blue = unchecked ((byte)((colors[0].Blue + 2 * colors[1].Blue + 1) / 3));
colors[3].Green = unchecked ((byte)((colors[0].Green + 2 * colors[1].Green + 1) / 3));
colors[3].Red = unchecked ((byte)((colors[0].Red + 2 * colors[1].Red + 1) / 3));
int bitIndex = 0;
for (int ly = 0; ly < 4; ly++)
{
for (int lx = 0; lx < 4; lx++, bitIndex++)
{
int colorIndex = unchecked ((int)((bitMask & (3 << bitIndex * 2)) >> bitIndex * 2));
Color8888 color = colors[colorIndex];
color.Alpha = alphas[bitIndex];
if ((x + lx) < width && (y - ly) < height && (y - ly) >= 0)
{
// mirror Y
long offset = z * sizeOfPlane + (y - ly) * bps + (x + lx) * bpp;
destination.Position = position + offset;
destination.WriteByte(color.Red);
destination.WriteByte(color.Green);
destination.WriteByte(color.Blue);
destination.WriteByte(color.Alpha);
}
}
}
}
}
}
}
}
