Files
maszyna/TextureDDS.cpp
2015-04-03 22:01:10 +08:00

331 lines
12 KiB
C++

#include "TextureDDS.h"
void DxtcReadColors(const GLubyte *Data, Color8888 *result)
{
GLubyte r0, g0, b0, r1, g1, b1;
b0 = Data[0] & 0x1F;
g0 = ((Data[0] & 0xE0) >> 5) | ((Data[1] & 0x7) << 3);
r0 = (Data[1] & 0xF8) >> 3;
b1 = Data[2] & 0x1F;
g1 = ((Data[2] & 0xE0) >> 5) | ((Data[3] & 0x7) << 3);
r1 = (Data[3] & 0xF8) >> 3;
result[0].r = r0 << 3 | r0 >> 2;
result[0].g = g0 << 2 | g0 >> 3;
result[0].b = b0 << 3 | b0 >> 2;
result[1].r = r1 << 3 | r1 >> 2;
result[1].g = g1 << 2 | g1 >> 3;
result[1].b = b1 << 3 | b1 >> 2;
};
void DxtcReadColor(GLushort Data, Color8888 *Out)
{
GLubyte r, g, b;
b = Data & 0x1f;
g = (Data & 0x7E0) >> 5;
r = (Data & 0xF800) >> 11;
Out->r = r << 3 | r >> 2;
Out->g = g << 2 | g >> 3;
Out->b = b << 3 | r >> 2;
};
void DecompressDXT1(DDS_IMAGE_DATA lImage, const GLubyte *lCompData, GLubyte *Data)
{
GLint x, y, i, j, k;
GLuint Select;
const GLubyte *Temp;
Color8888 colours[4], *col;
GLushort color_0, color_1;
GLuint bitmask, Offset;
Temp = lCompData;
colours[0].a = 0xFF;
colours[1].a = 0xFF;
colours[2].a = 0xFF;
for (y = 0; y < lImage.height; y += 4)
{
for (x = 0; x < lImage.width; x += 4)
{
color_0 = *((const GLushort *)Temp);
color_1 = *((const GLushort *)(Temp + 2));
DxtcReadColor(color_0, colours);
DxtcReadColor(color_1, colours + 1);
bitmask = ((const GLuint *)Temp)[1];
Temp += 8;
if (color_0 > color_1)
{
// 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 = (2 * colours[0].b + colours[1].b + 1) / 3;
colours[2].g = (2 * colours[0].g + colours[1].g + 1) / 3;
colours[2].r = (2 * colours[0].r + colours[1].r + 1) / 3;
colours[3].b = (colours[0].b + 2 * colours[1].b + 1) / 3;
colours[3].g = (colours[0].g + 2 * colours[1].g + 1) / 3;
colours[3].r = (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 = (colours[0].b + colours[1].b) / 2;
colours[2].g = (colours[0].g + colours[1].g) / 2;
colours[2].r = (colours[0].r + colours[1].r) / 2;
colours[3].b = (colours[0].b + 2 * colours[1].b + 1) / 3;
colours[3].g = (colours[0].g + 2 * colours[1].g + 1) / 3;
colours[3].r = (colours[0].r + 2 * colours[1].r + 1) / 3;
colours[3].a = 0x00;
}
for (j = 0, k = 0; j < 4; j++)
{
for (i = 0; i < 4; i++, k++)
{
Select = (bitmask & (0x03 << k * 2)) >> k * 2;
col = &colours[Select];
if (((x + i) < lImage.width) && ((y + j) < lImage.height))
{
Offset = (y + j) * lImage.width * lImage.components +
(x + i) * lImage.components;
Data[Offset + 0] = col->r;
Data[Offset + 1] = col->g;
Data[Offset + 2] = col->b;
Data[Offset + 3] = col->a;
}
}
}
}
}
}
void DecompressDXT3(DDS_IMAGE_DATA lImage, const GLubyte *lCompData, GLubyte *Data)
{
const GLubyte *Temp = lCompData;
Color8888 colours[4], *col;
GLuint bitmask, Offset;
const GLubyte *alpha;
for (GLint y = 0; y < lImage.height; y += 4)
{
for (GLint x = 0; x < lImage.width; x += 4)
{
alpha = Temp;
Temp += 8;
DxtcReadColors(Temp, colours);
bitmask = ((GLuint *)Temp)[1];
Temp += 8;
// 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 = (2 * colours[0].b + colours[1].b + 1) / 3;
colours[2].g = (2 * colours[0].g + colours[1].g + 1) / 3;
colours[2].r = (2 * colours[0].r + colours[1].r + 1) / 3;
colours[3].b = (colours[0].b + 2 * colours[1].b + 1) / 3;
colours[3].g = (colours[0].g + 2 * colours[1].g + 1) / 3;
colours[3].r = (colours[0].r + 2 * colours[1].r + 1) / 3;
GLuint k = 0;
for (GLint j = 0; j < 4; j++)
{
for (GLint i = 0; i < 4; i++, k++)
{
GLuint Select = (bitmask & (0x03 << k * 2)) >> k * 2;
col = &colours[Select];
if (((x + i) < lImage.width) && ((y + j) < lImage.height))
{
Offset = (y + j) * lImage.width * lImage.components +
(x + i) * lImage.components;
Data[Offset + 0] = col->r;
Data[Offset + 1] = col->g;
Data[Offset + 2] = col->b;
}
}
}
for (GLint j = 0; j < 4; j++)
{
GLushort word = alpha[2 * j] + 256 * alpha[2 * j + 1];
for (GLint i = 0; i < 4; i++)
{
if (((x + i) < lImage.width) && ((y + j) < lImage.height))
{
Offset = (y + j) * lImage.width * lImage.components +
(x + i) * lImage.components + 3;
Data[Offset] = word & 0x0F;
Data[Offset] = Data[Offset] | (Data[Offset] << 4);
}
word >>= 4;
}
}
}
}
}
void DecompressDXT5(DDS_IMAGE_DATA lImage, const GLubyte *lCompData, GLubyte *Data)
{
GLint x, y, z, i, j, k;
GLuint Select;
const GLubyte *Temp; //, r0, g0, b0, r1, g1, b1;
Color8888 colours[4], *col;
GLuint bitmask, Offset;
GLubyte alphas[8];
GLuint bits;
Temp = lCompData;
for (y = 0; y < lImage.height; y += 4)
{
for (x = 0; x < lImage.width; x += 4)
{
if (y >= lImage.height || x >= lImage.width)
break;
alphas[0] = Temp[0];
alphas[1] = Temp[1];
const GLubyte *alphamask = Temp + 2;
Temp += 8;
DxtcReadColors(Temp, colours);
bitmask = ((const GLuint *)Temp)[1];
Temp += 8;
// 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 = (2 * colours[0].b + colours[1].b + 1) / 3;
colours[2].g = (2 * colours[0].g + colours[1].g + 1) / 3;
colours[2].r = (2 * colours[0].r + colours[1].r + 1) / 3;
colours[3].b = (colours[0].b + 2 * colours[1].b + 1) / 3;
colours[3].g = (colours[0].g + 2 * colours[1].g + 1) / 3;
colours[3].r = (colours[0].r + 2 * colours[1].r + 1) / 3;
k = 0;
for (j = 0; j < 4; j++)
{
for (i = 0; i < 4; i++, k++)
{
Select = (bitmask & (0x03 << k * 2)) >> k * 2;
col = &colours[Select];
// only put pixels out < width or height
if (((x + i) < lImage.width) && ((y + j) < lImage.height))
{
Offset = (y + j) * lImage.width * lImage.components +
(x + i) * lImage.components;
Data[Offset + 0] = col->r;
Data[Offset + 1] = col->g;
Data[Offset + 2] = col->b;
}
}
}
// 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] = (6 * alphas[0] + 1 * alphas[1] + 3) / 7; // bit code 010
alphas[3] = (5 * alphas[0] + 2 * alphas[1] + 3) / 7; // bit code 011
alphas[4] = (4 * alphas[0] + 3 * alphas[1] + 3) / 7; // bit code 100
alphas[5] = (3 * alphas[0] + 4 * alphas[1] + 3) / 7; // bit code 101
alphas[6] = (2 * alphas[0] + 5 * alphas[1] + 3) / 7; // bit code 110
alphas[7] = (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] = (4 * alphas[0] + 1 * alphas[1] + 2) / 5; // Bit code 010
alphas[3] = (3 * alphas[0] + 2 * alphas[1] + 2) / 5; // Bit code 011
alphas[4] = (2 * alphas[0] + 3 * alphas[1] + 2) / 5; // Bit code 100
alphas[5] = (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
// bits = *((ILint*)alphamask);
bits = (alphamask[0]) | (alphamask[1] << 8) | (alphamask[2] << 16);
for (j = 0; j < 2; j++)
{
for (i = 0; i < 4; i++)
{
// only put pixels out < width or height
if (((x + i) < lImage.width) && ((y + j) < lImage.height))
{
Offset = (y + j) * lImage.width * lImage.components +
(x + i) * lImage.components + 3;
Data[Offset] = alphas[bits & 0x07];
}
bits >>= 3;
}
}
// Last three bytes
// bits = *((ILint*)&alphamask[3]);
bits = (alphamask[3]) | (alphamask[4] << 8) | (alphamask[5] << 16);
for (j = 2; j < 4; j++)
{
for (i = 0; i < 4; i++)
{
// only put pixels out < width or height
if (((x + i) < lImage.width) && ((y + j) < lImage.height))
{
Offset = (y + j) * lImage.width * lImage.components +
(x + i) * lImage.components + 3;
Data[Offset] = alphas[bits & 0x07];
}
bits >>= 3;
}
}
}
}
}
void DecompressDXT(DDS_IMAGE_DATA lImage, const GLubyte *lCompData, GLubyte *Data)
{
switch (lImage.format)
{
case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
DecompressDXT1(lImage, lCompData, Data);
break;
case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
DecompressDXT3(lImage, lCompData, Data);
break;
case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
DecompressDXT5(lImage, lCompData, Data);
break;
};
}