private void DecompressDXT3()
{
Colour8888[] colours = new Colour8888[4];
uint bitmask, offset;
int i, j, k, x, y, z, Select;
ushort word, colour0, colour1;
byte[] alpha; //temp;
MemoryStream mem = new MemoryStream(this.compdata.Length);
mem.Write(this.compdata, 0, this.compdata.Length);
mem.Seek(0, SeekOrigin.Begin);
BinaryReader r = new BinaryReader(mem);
for (z=0; z<this.depth; z++) {
for (y=0; y<this.height; y+=4) {
for (x=0; x<this.width; x+=4) {
alpha = r.ReadBytes(8);
colour0 = r.ReadUInt16();
colour1 = r.ReadUInt16();
this.ReadColour(colour0, ref colours[0]);
this.ReadColour(colour1, ref colours[1]);
bitmask = r.ReadUInt32();
colours[2].b = (byte)((2 * colours[0].b + colours[1].b + 1) / 3);
colours[2].g = (byte)((2 * colours[0].g + colours[1].g + 1) / 3);
colours[2].r = (byte)((2 * colours[0].r + colours[1].r + 1) / 3);
colours[3].b = (byte)((colours[0].b + 2 * colours[1].b + 1) / 3);
colours[3].g = (byte)((colours[0].g + 2 * colours[1].g + 1) / 3);
colours[3].r = (byte)((colours[0].r + 2 * colours[1].r + 1) / 3);
for (j = 0, k = 0; j < 4; j++) {
for (i = 0; i < 4; k++, i++) {
Select = (int)((bitmask & (0x03 << k*2)) >> k*2);
if (((x + i) < this.width) && ((y + j) < this.height)) {
offset = (uint)(z * this.sizeofplane + (y + j) * this.bps + (x + i) * this.bpp);
this.rawidata[offset] = (byte)colours[Select].r;
this.rawidata[offset + 1] = (byte)colours[Select].g;
this.rawidata[offset + 2] = (byte)colours[Select].b;
}
}
}
for (j = 0; j < 4; j++) {
word = (ushort)(alpha[2*j] + 256*alpha[2*j+1]);
for (i = 0; i < 4; i++) {
if (((x + i) < this.width) && ((y + j) < this.height)) {
offset = (uint)(z * this.sizeofplane + (y + j) * this.bps + (x + i) * this.bpp + 3);
this.rawidata[offset] = (byte)(word & 0x0F);
this.rawidata[offset] = (byte)(this.rawidata[offset] | (this.rawidata[offset] << 4));
}
word >>= 4;
}
}
}
}
}
}
private void ReadColour(ushort Data, ref Colour8888 op)
{
byte r, g, b;
b = (byte)(Data & 0x1f);
g = (byte)((Data & 0x7E0) >> 5);
r = (byte)((Data & 0xF800) >> 11);
op.r = (byte)(r * 255 / 31);
op.g = (byte)(g * 255 / 63);
op.b = (byte)(b * 255 / 31);
}
private void DecompressDXT1()
{
// DXT1 decompressor
Colour8888[] colours = new Colour8888[4];
ushort colour0, colour1;
uint bitmask, offset;
int i, j, k, x, y, z, Select;
MemoryStream mem = new MemoryStream(this.compdata.Length);
mem.Write(this.compdata, 0, this.compdata.Length);
mem.Seek(0, SeekOrigin.Begin);
BinaryReader r = new BinaryReader(mem);
colours[0].a = 255;
colours[1].a = 255;
colours[2].a = 255;
for (z=0; z<this.depth; z++) {
for (y=0; y<this.height; y+=4) {
for (x=0; x<this.width; x+=4) {
colour0 = r.ReadUInt16();
colour1 = r.ReadUInt16();
this.ReadColour(colour0, ref colours[0]);
this.ReadColour(colour1, ref colours[1]);
bitmask = r.ReadUInt32();
if (colour0 > colour1) {
// 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.
colours[2].b = (byte)((2 * colours[0].b + colours[1].b + 1) / 3);
colours[2].g = (byte)((2 * colours[0].g + colours[1].g + 1) / 3);
colours[2].r = (byte)((2 * colours[0].r + colours[1].r + 1) / 3);
colours[3].b = (byte)((colours[0].b + 2 * colours[1].b + 1) / 3);
colours[3].g = (byte)((colours[0].g + 2 * colours[1].g + 1) / 3);
colours[3].r = (byte)((colours[0].r + 2 * colours[1].r + 1) / 3);
colours[3].a = 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.
colours[2].b = (byte)((colours[0].b + colours[1].b) / 2);
colours[2].g = (byte)((colours[0].g + colours[1].g) / 2);
colours[2].r = (byte)((colours[0].r + colours[1].r) / 2);
colours[3].b = 0;
colours[3].g = 0;
colours[3].r = 0;
colours[3].a = 0;
}
for (j = 0, k = 0; j < 4; j++) {
for (i = 0; i < 4; i++, k++) {
Select = (int)((bitmask & (0x03 << k*2)) >> k*2);
if (((x + i) < this.width) && ((y + j) < this.height)) {
offset = (uint)(z * this.sizeofplane + (y + j) * this.bps + (x + i) * this.bpp);
this.rawidata[offset] = (byte)colours[Select].r;
this.rawidata[offset + 1] = (byte)colours[Select].g;
this.rawidata[offset + 2] = (byte)colours[Select].b;
this.rawidata[offset + 3] = (byte)colours[Select].a;
}
}
}
}
}
}
}
