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Move endpoint optimization to QuickCompress.

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This commit is contained in:
castano 2007-09-05 00:12:59 +00:00
parent a19df8721d
commit 793611fe7f
2 changed files with 52 additions and 9 deletions
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2
src/nvimage/nvtt/CompressDXT.cpp
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@ -69,8 +69,6 @@ void nv::fastCompressDXT1(const Image * image, const OutputOptions & outputOptio
QuickCompress::compressDXT1(rgba, &block);
optimizeEndPoints(rgba, &block);
if (outputOptions.outputHandler != NULL) {
outputOptions.outputHandler->writeData(&block, sizeof(block));
}

59
src/nvimage/nvtt/QuickCompressDXT.cpp
View File

@ -22,24 +22,24 @@
// OTHER DEALINGS IN THE SOFTWARE.
#include <nvmath/Color.h>
#include <nvimage/ColorBlock.h>
#include <nvimage/BlockDXT.h>
#include "QuickCompressDXT.h"
using namespace nv;
using namespace QuickCompress;
inline static Vector3 loadColor(Color32 c)
{
return Vector3(c.r, c.g, c.b);
}
inline static void extractColorBlockRGB(const ColorBlock & rgba, Vector3 block[16])
{
for (int i = 0; i < 16; i++)
{
block[i] = loadColor(rgba.color(i));
const Color32 c = rgba.color(i);
block[i] = Vector3(c.r, c.g, c.b);
}
}
@ -143,6 +143,51 @@ inline static uint computeIndices(Vector3 block[16], Vector3::Arg maxColor, Vect
return indices;
}
static void optimizeEndPoints(Vector3 block[16], BlockDXT1 * dxtBlock)
{
float alpha2_sum = 0.0f;
float beta2_sum = 0.0f;
float alphabeta_sum = 0.0f;
Vector3 alphax_sum(zero);
Vector3 betax_sum(zero);
for( int i = 0; i < 16; ++i )
{
const uint bits = dxtBlock->indices >> (2 * i);
float beta = (bits & 1);
if (bits & 2) beta = (1 + beta) / 3.0f;
float alpha = 1.0f - beta;
alpha2_sum += alpha * alpha;
beta2_sum += beta * beta;
alphabeta_sum += alpha * beta;
alphax_sum += alpha * block[i];
betax_sum += beta * block[i];
}
float factor = 1.0f / (alpha2_sum * beta2_sum - alphabeta_sum * alphabeta_sum);
Vector3 a = (alphax_sum * beta2_sum - betax_sum * alphabeta_sum) * factor;
Vector3 b = (betax_sum * alpha2_sum - alphax_sum * alphabeta_sum) * factor;
a = clamp(a, 0, 255);
b = clamp(b, 0, 255);
uint16 color0 = roundAndExpand(&a);
uint16 color1 = roundAndExpand(&b);
if (color0 < color1)
{
swap(a, b);
swap(color0, color1);
}
dxtBlock->col0 = Color16(color0);
dxtBlock->col1 = Color16(color1);
dxtBlock->indices = computeIndices(block, a, b);
}
void QuickCompress::compressDXT1(const ColorBlock & rgba, BlockDXT1 * dxtBlock)
{
@ -167,11 +212,11 @@ void QuickCompress::compressDXT1(const ColorBlock & rgba, BlockDXT1 * dxtBlock)
swap(color0, color1);
}
// @@ Optimize endpoints.
dxtBlock->col0 = Color16(color0);
dxtBlock->col1 = Color16(color1);
dxtBlock->indices = computeIndices(block, maxColor, minColor);
optimizeEndPoints(block, dxtBlock);
}