#include "PVRTC.h"
#include "Utils.h"
#include <assert.h>
#include <math.h>
#include <stdint.h>
//============================================================================
const unsigned char PvrTcPacket::BILINEAR_FACTORS[16][4] =
{
{ 4, 4, 4, 4 },
{ 2, 6, 2, 6 },
{ 8, 0, 8, 0 },
{ 6, 2, 6, 2 },
{ 2, 2, 6, 6 },
{ 1, 3, 3, 9 },
{ 4, 0, 12, 0 },
{ 3, 1, 9, 3 },
{ 8, 8, 0, 0 },
{ 4, 12, 0, 0 },
{ 16, 0, 0, 0 },
{ 12, 4, 0, 0 },
{ 6, 6, 2, 2 },
{ 3, 9, 1, 3 },
{ 12, 0, 4, 0 },
{ 9, 3, 3, 1 },
};
// Weights are { colorA, colorB, alphaA, alphaB }
const unsigned char PvrTcPacket::WEIGHTS[8][4] =
{
// Weights for Mode=0
{ 8, 0, 8, 0 },
{ 5, 3, 5, 3 },
{ 3, 5, 3, 5 },
{ 0, 8, 0, 8 },
// Weights for Mode=1
{ 8, 0, 8, 0 },
{ 4, 4, 4, 4 },
{ 4, 4, 0, 0 },
{ 0, 8, 0, 8 },
};
//============================================================================
ColorRgb<int> PvrTcPacket::GetColorRgbA() const
{
if(colorAIsOpaque)
{
unsigned char r = colorA >> 9;
unsigned char g = colorA >> 4 & 0x1f;
unsigned char b = colorA & 0xf;
return ColorRgb<int>(Data::BITSCALE_5_TO_8[r],
Data::BITSCALE_5_TO_8[g],
Data::BITSCALE_4_TO_8[b]);
}
else
{
unsigned char r = (colorA >> 7) & 0xf;
unsigned char g = (colorA >> 3) & 0xf;
unsigned char b = colorA & 7;
return ColorRgb<int>(Data::BITSCALE_4_TO_8[r],
Data::BITSCALE_4_TO_8[g],
Data::BITSCALE_3_TO_8[b]);
}
}
ColorRgb<int> PvrTcPacket::GetColorRgbB() const
{
if(colorBIsOpaque)
{
unsigned char r = colorB >> 10;
unsigned char g = colorB >> 5 & 0x1f;
unsigned char b = colorB & 0x1f;
return ColorRgb<int>(Data::BITSCALE_5_TO_8[r],
Data::BITSCALE_5_TO_8[g],
Data::BITSCALE_5_TO_8[b]);
}
else
{
unsigned char r = colorB >> 8 & 0xf;
unsigned char g = colorB >> 4 & 0xf;
unsigned char b = colorB & 0xf;
return ColorRgb<int>(Data::BITSCALE_4_TO_8[r],
Data::BITSCALE_4_TO_8[g],
Data::BITSCALE_4_TO_8[b]);
}
}
ColorRgba<int> PvrTcPacket::GetColorRgbaA() const
{
if(colorAIsOpaque)
{
unsigned char r = colorA >> 9;
unsigned char g = colorA >> 4 & 0x1f;
unsigned char b = colorA & 0xf;
return ColorRgba<int>(Data::BITSCALE_5_TO_8[r],
Data::BITSCALE_5_TO_8[g],
Data::BITSCALE_4_TO_8[b],
255);
}
else
{
unsigned char a = colorA >> 11 & 7;
unsigned char r = colorA >> 7 & 0xf;
unsigned char g = colorA >> 3 & 0xf;
unsigned char b = colorA & 7;
return ColorRgba<int>(Data::BITSCALE_4_TO_8[r],
Data::BITSCALE_4_TO_8[g],
Data::BITSCALE_3_TO_8[b],
Data::BITSCALE_3_TO_8[a]);
}
}
ColorRgba<int> PvrTcPacket::GetColorRgbaB() const
{
if(colorBIsOpaque)
{
unsigned char r = colorB >> 10;
unsigned char g = colorB >> 5 & 0x1f;
unsigned char b = colorB & 0x1f;
return ColorRgba<int>(Data::BITSCALE_5_TO_8[r],
Data::BITSCALE_5_TO_8[g],
Data::BITSCALE_5_TO_8[b],
255);
}
else
{
unsigned char a = colorB >> 12 & 7;
unsigned char r = colorB >> 8 & 0xf;
unsigned char g = colorB >> 4 & 0xf;
unsigned char b = colorB & 0xf;
return ColorRgba<int>(Data::BITSCALE_4_TO_8[r],
Data::BITSCALE_4_TO_8[g],
Data::BITSCALE_4_TO_8[b],
Data::BITSCALE_3_TO_8[a]);
}
}
//============================================================================
void PvrTcPacket::SetColorA(const ColorRgb<unsigned char>& c)
{
int r = Data::BITSCALE_8_TO_5_FLOOR[c.r];
int g = Data::BITSCALE_8_TO_5_FLOOR[c.g];
int b = Data::BITSCALE_8_TO_4_FLOOR[c.b];
colorA = r<<9 | g<<4 | b;
colorAIsOpaque = true;
}
void PvrTcPacket::SetColorB(const ColorRgb<unsigned char>& c)
{
int r = Data::BITSCALE_8_TO_5_CEIL[c.r];
int g = Data::BITSCALE_8_TO_5_CEIL[c.g];
int b = Data::BITSCALE_8_TO_5_CEIL[c.b];
colorB = r<<10 | g<<5 | b;
colorBIsOpaque = true;
}
void PvrTcPacket::SetColorA(const ColorRgba<unsigned char>& c)
{
int a = Data::BITSCALE_8_TO_3_FLOOR[c.a];
if(a == 7)
{
int r = Data::BITSCALE_8_TO_5_FLOOR[c.r];
int g = Data::BITSCALE_8_TO_5_FLOOR[c.g];
int b = Data::BITSCALE_8_TO_4_FLOOR[c.b];
colorA = r<<9 | g<<4 | b;
colorAIsOpaque = true;
}
else
{
int r = Data::BITSCALE_8_TO_4_FLOOR[c.r];
int g = Data::BITSCALE_8_TO_4_FLOOR[c.g];
int b = Data::BITSCALE_8_TO_3_FLOOR[c.b];
colorA = a<<11 | r<<7 | g<<3 | b;
colorAIsOpaque = false;
}
}
void PvrTcPacket::SetColorB(const ColorRgba<unsigned char>& c)
{
int a = Data::BITSCALE_8_TO_3_CEIL[c.a];
if(a == 7)
{
int r = Data::BITSCALE_8_TO_5_CEIL[c.r];
int g = Data::BITSCALE_8_TO_5_CEIL[c.g];
int b = Data::BITSCALE_8_TO_5_CEIL[c.b];
colorB = r<<10 | g<<5 | b;
colorBIsOpaque = true;
}
else
{
int r = Data::BITSCALE_8_TO_4_CEIL[c.r];
int g = Data::BITSCALE_8_TO_4_CEIL[c.g];
int b = Data::BITSCALE_8_TO_4_CEIL[c.b];
colorB = a<<12 | r<<8 | g<<4 | b;
colorBIsOpaque = false;
}
}
//============================================================================
//============================================================================
//============================================================================
using Data::MORTON_TABLE;
//============================================================================
static const unsigned char MODULATION_LUT[16] =
{
0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3
};
//============================================================================
inline unsigned PvrTcEncoder::GetMortonNumber(int x, int y)
{
return MORTON_TABLE[x >> 8] << 17 | MORTON_TABLE[y >> 8] << 16 | MORTON_TABLE[x & 0xFF] << 1 | MORTON_TABLE[y & 0xFF];
}
//============================================================================
void PvrTcEncoder::EncodeAlpha2Bpp(void* result, const AlphaBitmap& bitmap)
{
int size = bitmap.GetBitmapWidth();
assert(size == bitmap.GetBitmapHeight());
assert(BitUtility::IsPowerOf2(size));
// Blocks in each dimension.
int xBlocks = size/8;
int yBlocks = size/4;
const unsigned char* bitmapData = bitmap.GetRawData();
PvrTcPacket* packets = static_cast<PvrTcPacket*>(result);
for(int y = 0; y < yBlocks; ++y)
{
for(int x = 0; x < xBlocks; ++x)
{
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->usePunchthroughAlpha = 0;
packet->colorAIsOpaque = 0;
packet->colorA = 0x7ff; // White, with 0 alpha
packet->colorBIsOpaque = 1;
packet->colorB = 0x7fff; // White with full alpha
const unsigned char* blockBitmapData = &bitmapData[y*4*size + x*8];
uint32_t modulationData = 0;
for(int py = 0; py < 4; ++py)
{
const unsigned char* rowBitmapData = blockBitmapData;
for(int px = 0; px < 8; ++px)
{
unsigned char pixel = *rowBitmapData++;
modulationData = BitUtility::RotateRight(modulationData | (pixel >> 7), 1);
}
blockBitmapData += size;
}
packet->modulationData = modulationData;
}
}
}
void PvrTcEncoder::EncodeAlpha4Bpp(void* result, const AlphaBitmap& bitmap)
{
int size = bitmap.GetBitmapWidth();
assert(size == bitmap.GetBitmapHeight());
assert(BitUtility::IsPowerOf2(size));
// Blocks in each dimension.
int blocks = size/4;
const unsigned char* bitmapData = bitmap.GetRawData();
PvrTcPacket* packets = static_cast<PvrTcPacket*>(result);
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->usePunchthroughAlpha = 0;
packet->colorAIsOpaque = 0;
packet->colorA = 0x7ff; // White, with 0 alpha
packet->colorBIsOpaque = 1;
packet->colorB = 0x7fff; // White with full alpha
const unsigned char* blockBitmapData = &bitmapData[(y*size + x)*4];
uint32_t modulationData = 0;
for(int py = 0; py < 4; ++py)
{
const unsigned char* rowBitmapData = blockBitmapData;
for(int px = 0; px < 4; ++px)
{
unsigned char pixel = *rowBitmapData++;
modulationData = BitUtility::RotateRight(modulationData | MODULATION_LUT[pixel>>4], 2);
}
blockBitmapData += size;
}
packet->modulationData = modulationData;
}
}
}
//============================================================================
typedef Interval<ColorRgb<unsigned char>> ColorRgbBoundingBox;
static void CalculateBoundingBox(ColorRgbBoundingBox& cbb, const RgbBitmap& bitmap, int blockX, int blockY)
{
int size = bitmap.GetBitmapWidth();
const ColorRgb<unsigned char>* data = bitmap.GetData() + blockY * 4 * size + blockX * 4;
cbb.min = data[0];
cbb.max = data[0];
cbb |= data[1];
cbb |= data[2];
cbb |= data[3];
cbb |= data[size];
cbb |= data[size+1];
cbb |= data[size+2];
cbb |= data[size+3];
cbb |= data[2*size];
cbb |= data[2*size+1];
cbb |= data[2*size+2];
cbb |= data[2*size+3];
cbb |= data[3*size];
cbb |= data[3*size+1];
cbb |= data[3*size+2];
cbb |= data[3*size+3];
}
void PvrTcEncoder::EncodeRgb4Bpp(void* result, const RgbBitmap& bitmap)
{
assert(bitmap.GetBitmapWidth() == bitmap.GetBitmapHeight());
assert(BitUtility::IsPowerOf2(bitmap.GetBitmapWidth()));
const int size = bitmap.GetBitmapWidth();
const int blocks = size / 4;
const int blockMask = blocks-1;
PvrTcPacket* packets = static_cast<PvrTcPacket*>(result);
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
ColorRgbBoundingBox cbb;
CalculateBoundingBox(cbb, bitmap, x, y);
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->usePunchthroughAlpha = 0;
packet->SetColorA(cbb.min);
packet->SetColorB(cbb.max);
}
}
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
const unsigned char (*factor)[4] = PvrTcPacket::BILINEAR_FACTORS;
const ColorRgb<unsigned char>* data = bitmap.GetData() + y * 4 * size + x * 4;
uint32_t modulationData = 0;
for(int py = 0; py < 4; ++py)
{
const int yOffset = (py < 2) ? -1 : 0;
const int y0 = (y + yOffset) & blockMask;
const int y1 = (y0+1) & blockMask;
for(int px = 0; px < 4; ++px)
{
const int xOffset = (px < 2) ? -1 : 0;
const int x0 = (x + xOffset) & blockMask;
const int x1 = (x0+1) & blockMask;
const PvrTcPacket* p0 = packets + GetMortonNumber(x0, y0);
const PvrTcPacket* p1 = packets + GetMortonNumber(x1, y0);
const PvrTcPacket* p2 = packets + GetMortonNumber(x0, y1);
const PvrTcPacket* p3 = packets + GetMortonNumber(x1, y1);
ColorRgb<int> ca = p0->GetColorRgbA() * (*factor)[0] +
p1->GetColorRgbA() * (*factor)[1] +
p2->GetColorRgbA() * (*factor)[2] +
p3->GetColorRgbA() * (*factor)[3];
ColorRgb<int> cb = p0->GetColorRgbB() * (*factor)[0] +
p1->GetColorRgbB() * (*factor)[1] +
p2->GetColorRgbB() * (*factor)[2] +
p3->GetColorRgbB() * (*factor)[3];
const ColorRgb<unsigned char>& pixel = data[py*size + px];
ColorRgb<int> d = cb - ca;
ColorRgb<int> p{pixel.r*16, pixel.g*16, pixel.b*16};
ColorRgb<int> v = p - ca;
// PVRTC uses weightings of 0, 3/8, 5/8 and 1
// The boundaries for these are 3/16, 1/2 (=8/16), 13/16
int projection = (v % d) * 16;
int lengthSquared = d % d;
if(projection > 3*lengthSquared) modulationData++;
if(projection > 8*lengthSquared) modulationData++;
if(projection > 13*lengthSquared) modulationData++;
modulationData = BitUtility::RotateRight(modulationData, 2);
factor++;
}
}
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->modulationData = modulationData;
}
}
}
//============================================================================
static void CalculateBoundingBox(ColorRgbBoundingBox& cbb, const RgbaBitmap& bitmap, int blockX, int blockY)
{
int size = bitmap.GetBitmapWidth();
const ColorRgba<unsigned char>* data = bitmap.GetData() + blockY * 4 * size + blockX * 4;
cbb.min = data[0];
cbb.max = data[0];
cbb |= data[1];
cbb |= data[2];
cbb |= data[3];
cbb |= data[size];
cbb |= data[size+1];
cbb |= data[size+2];
cbb |= data[size+3];
cbb |= data[2*size];
cbb |= data[2*size+1];
cbb |= data[2*size+2];
cbb |= data[2*size+3];
cbb |= data[3*size];
cbb |= data[3*size+1];
cbb |= data[3*size+2];
cbb |= data[3*size+3];
}
void PvrTcEncoder::EncodeRgb4Bpp(void* result, const RgbaBitmap& bitmap)
{
assert(bitmap.GetBitmapWidth() == bitmap.GetBitmapHeight());
assert(BitUtility::IsPowerOf2(bitmap.GetBitmapWidth()));
const int size = bitmap.GetBitmapWidth();
const int blocks = size / 4;
const int blockMask = blocks-1;
PvrTcPacket* packets = static_cast<PvrTcPacket*>(result);
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
ColorRgbBoundingBox cbb;
CalculateBoundingBox(cbb, bitmap, x, y);
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->usePunchthroughAlpha = 0;
packet->SetColorA(cbb.min);
packet->SetColorB(cbb.max);
}
}
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
const unsigned char (*factor)[4] = PvrTcPacket::BILINEAR_FACTORS;
const ColorRgba<unsigned char>* data = bitmap.GetData() + y * 4 * size + x * 4;
uint32_t modulationData = 0;
for(int py = 0; py < 4; ++py)
{
const int yOffset = (py < 2) ? -1 : 0;
const int y0 = (y + yOffset) & blockMask;
const int y1 = (y0+1) & blockMask;
for(int px = 0; px < 4; ++px)
{
const int xOffset = (px < 2) ? -1 : 0;
const int x0 = (x + xOffset) & blockMask;
const int x1 = (x0+1) & blockMask;
const PvrTcPacket* p0 = packets + GetMortonNumber(x0, y0);
const PvrTcPacket* p1 = packets + GetMortonNumber(x1, y0);
const PvrTcPacket* p2 = packets + GetMortonNumber(x0, y1);
const PvrTcPacket* p3 = packets + GetMortonNumber(x1, y1);
ColorRgb<int> ca = p0->GetColorRgbA() * (*factor)[0] +
p1->GetColorRgbA() * (*factor)[1] +
p2->GetColorRgbA() * (*factor)[2] +
p3->GetColorRgbA() * (*factor)[3];
ColorRgb<int> cb = p0->GetColorRgbB() * (*factor)[0] +
p1->GetColorRgbB() * (*factor)[1] +
p2->GetColorRgbB() * (*factor)[2] +
p3->GetColorRgbB() * (*factor)[3];
const ColorRgb<unsigned char>& pixel = data[py*size + px];
ColorRgb<int> d = cb - ca;
ColorRgb<int> p{pixel.r*16, pixel.g*16, pixel.b*16};
ColorRgb<int> v = p - ca;
// PVRTC uses weightings of 0, 3/8, 5/8 and 1
// The boundaries for these are 3/16, 1/2 (=8/16), 13/16
int projection = (v % d) * 16;
int lengthSquared = d % d;
if(projection > 3*lengthSquared) modulationData++;
if(projection > 8*lengthSquared) modulationData++;
if(projection > 13*lengthSquared) modulationData++;
modulationData = BitUtility::RotateRight(modulationData, 2);
factor++;
}
}
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->modulationData = modulationData;
}
}
}
//============================================================================
typedef Interval<ColorRgba<unsigned char>> ColorRgbaBoundingBox;
static void CalculateBoundingBox(ColorRgbaBoundingBox& cbb, const RgbaBitmap& bitmap, int blockX, int blockY)
{
int size = bitmap.GetBitmapWidth();
const ColorRgba<unsigned char>* data = bitmap.GetData() + blockY * 4 * size + blockX * 4;
cbb.min = data[0];
cbb.max = data[0];
cbb |= data[1];
cbb |= data[2];
cbb |= data[3];
cbb |= data[size];
cbb |= data[size+1];
cbb |= data[size+2];
cbb |= data[size+3];
cbb |= data[2*size];
cbb |= data[2*size+1];
cbb |= data[2*size+2];
cbb |= data[2*size+3];
cbb |= data[3*size];
cbb |= data[3*size+1];
cbb |= data[3*size+2];
cbb |= data[3*size+3];
}
void PvrTcEncoder::EncodeRgba4Bpp(void* result, const RgbaBitmap& bitmap)
{
assert(bitmap.GetBitmapWidth() == bitmap.GetBitmapHeight());
assert(BitUtility::IsPowerOf2(bitmap.GetBitmapWidth()));
const int size = bitmap.GetBitmapWidth();
const int blocks = size / 4;
const int blockMask = blocks-1;
PvrTcPacket* packets = static_cast<PvrTcPacket*>(result);
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
ColorRgbaBoundingBox cbb;
CalculateBoundingBox(cbb, bitmap, x, y);
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->usePunchthroughAlpha = 0;
packet->SetColorA(cbb.min);
packet->SetColorB(cbb.max);
}
}
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
const unsigned char (*factor)[4] = PvrTcPacket::BILINEAR_FACTORS;
const ColorRgba<unsigned char>* data = bitmap.GetData() + y * 4 * size + x * 4;
uint32_t modulationData = 0;
for(int py = 0; py < 4; ++py)
{
const int yOffset = (py < 2) ? -1 : 0;
const int y0 = (y + yOffset) & blockMask;
const int y1 = (y0+1) & blockMask;
for(int px = 0; px < 4; ++px)
{
const int xOffset = (px < 2) ? -1 : 0;
const int x0 = (x + xOffset) & blockMask;
const int x1 = (x0+1) & blockMask;
const PvrTcPacket* p0 = packets + GetMortonNumber(x0, y0);
const PvrTcPacket* p1 = packets + GetMortonNumber(x1, y0);
const PvrTcPacket* p2 = packets + GetMortonNumber(x0, y1);
const PvrTcPacket* p3 = packets + GetMortonNumber(x1, y1);
ColorRgba<int> ca = p0->GetColorRgbaA() * (*factor)[0] +
p1->GetColorRgbaA() * (*factor)[1] +
p2->GetColorRgbaA() * (*factor)[2] +
p3->GetColorRgbaA() * (*factor)[3];
ColorRgba<int> cb = p0->GetColorRgbaB() * (*factor)[0] +
p1->GetColorRgbaB() * (*factor)[1] +
p2->GetColorRgbaB() * (*factor)[2] +
p3->GetColorRgbaB() * (*factor)[3];
const ColorRgba<unsigned char>& pixel = data[py*size + px];
ColorRgba<int> d = cb - ca;
ColorRgba<int> p{pixel.r*16, pixel.g*16, pixel.b*16, pixel.a*16};
ColorRgba<int> v = p - ca;
// PVRTC uses weightings of 0, 3/8, 5/8 and 1
// The boundaries for these are 3/16, 1/2 (=8/16), 13/16
int projection = (v % d) * 16;
int lengthSquared = d % d;
if(projection > 3*lengthSquared) modulationData++;
if(projection > 8*lengthSquared) modulationData++;
if(projection > 13*lengthSquared) modulationData++;
modulationData = BitUtility::RotateRight(modulationData, 2);
factor++;
}
}
PvrTcPacket* packet = packets + GetMortonNumber(x, y);
packet->modulationData = modulationData;
}
}
}
//============================================================================
//============================================================================
using Data::MORTON_TABLE;
//============================================================================
inline unsigned GetMortonNumber(int x, int y)
{
return MORTON_TABLE[x >> 8] << 17 | MORTON_TABLE[y >> 8] << 16 | MORTON_TABLE[x & 0xFF] << 1 | MORTON_TABLE[y & 0xFF];
}
//============================================================================
void PvrTcDecoder::DecodeRgb4Bpp(ColorRgb<unsigned char>* result, int dim, const void* data)
{
const int blocks = dim / 4;
const int blockMask = blocks-1;
const PvrTcPacket* packets = static_cast<const PvrTcPacket*>(data);
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
const PvrTcPacket* packet = packets + GetMortonNumber(x, y);
unsigned mod = packet->modulationData;
const unsigned char (*weights)[4] = PvrTcPacket::WEIGHTS + 4*packet->usePunchthroughAlpha;
const unsigned char (*factor)[4] = PvrTcPacket::BILINEAR_FACTORS;
for(int py = 0; py < 4; ++py)
{
const int yOffset = (py < 2) ? -1 : 0;
const int y0 = (y + yOffset) & blockMask;
const int y1 = (y0+1) & blockMask;
for(int px = 0; px < 4; ++px)
{
const int xOffset = (px < 2) ? -1 : 0;
const int x0 = (x + xOffset) & blockMask;
const int x1 = (x0+1) & blockMask;
const PvrTcPacket* p0 = packets + GetMortonNumber(x0, y0);
const PvrTcPacket* p1 = packets + GetMortonNumber(x1, y0);
const PvrTcPacket* p2 = packets + GetMortonNumber(x0, y1);
const PvrTcPacket* p3 = packets + GetMortonNumber(x1, y1);
ColorRgb<int> ca = p0->GetColorRgbA() * (*factor)[0] +
p1->GetColorRgbA() * (*factor)[1] +
p2->GetColorRgbA() * (*factor)[2] +
p3->GetColorRgbA() * (*factor)[3];
ColorRgb<int> cb = p0->GetColorRgbB() * (*factor)[0] +
p1->GetColorRgbB() * (*factor)[1] +
p2->GetColorRgbB() * (*factor)[2] +
p3->GetColorRgbB() * (*factor)[3];
const unsigned char* w = weights[mod&3];
ColorRgb<unsigned char> c;
c.r = (ca.r * w[0] + cb.r * w[1]) >> 7;
c.g = (ca.g * w[0] + cb.g * w[1]) >> 7;
c.b = (ca.b * w[0] + cb.b * w[1]) >> 7;
result[(py+y*4)*dim + (px+x*4)] = c;
mod >>= 2;
factor++;
}
}
}
}
}
void PvrTcDecoder::DecodeRgba4Bpp(ColorRgba<unsigned char>* result, int dim, const void* data)
{
const int blocks = dim / 4;
const int blockMask = blocks-1;
const PvrTcPacket* packets = static_cast<const PvrTcPacket*>(data);
for(int y = 0; y < blocks; ++y)
{
for(int x = 0; x < blocks; ++x)
{
const PvrTcPacket* packet = packets + GetMortonNumber(x, y);
unsigned mod = packet->modulationData;
const unsigned char (*weights)[4] = PvrTcPacket::WEIGHTS + 4*packet->usePunchthroughAlpha;
const unsigned char (*factor)[4] = PvrTcPacket::BILINEAR_FACTORS;
for(int py = 0; py < 4; ++py)
{
const int yOffset = (py < 2) ? -1 : 0;
const int y0 = (y + yOffset) & blockMask;
const int y1 = (y0+1) & blockMask;
for(int px = 0; px < 4; ++px)
{
const int xOffset = (px < 2) ? -1 : 0;
const int x0 = (x + xOffset) & blockMask;
const int x1 = (x0+1) & blockMask;
const PvrTcPacket* p0 = packets + GetMortonNumber(x0, y0);
const PvrTcPacket* p1 = packets + GetMortonNumber(x1, y0);
const PvrTcPacket* p2 = packets + GetMortonNumber(x0, y1);
const PvrTcPacket* p3 = packets + GetMortonNumber(x1, y1);
ColorRgba<int> ca = p0->GetColorRgbaA() * (*factor)[0] +
p1->GetColorRgbaA() * (*factor)[1] +
p2->GetColorRgbaA() * (*factor)[2] +
p3->GetColorRgbaA() * (*factor)[3];
ColorRgba<int> cb = p0->GetColorRgbaB() * (*factor)[0] +
p1->GetColorRgbaB() * (*factor)[1] +
p2->GetColorRgbaB() * (*factor)[2] +
p3->GetColorRgbaB() * (*factor)[3];
const unsigned char* w = weights[mod&3];
ColorRgba<unsigned char> c;
c.r = (ca.r * w[0] + cb.r * w[1]) >> 7;
c.g = (ca.g * w[0] + cb.g * w[1]) >> 7;
c.b = (ca.b * w[0] + cb.b * w[1]) >> 7;
c.a = (ca.a * w[2] + cb.a * w[3]) >> 7;
result[(py+y*4)*dim + (px+x*4)] = c;
mod >>= 2;
factor++;
}
}
}
}
}
//============================================================================
