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DXT1 compressor tweaks.

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pull/216/head
castano 10 years ago
parent d019cd7080
commit 2d6fc0e304
5 changed files with 476 additions and 186 deletions
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23
src/nvtt/ClusterFit.cpp
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@ -411,19 +411,19 @@ bool ClusterFit::compress4( Vector3 * start, Vector3 * end )
#else
inline Vector3 round565(const Vector3 & v) {
uint r = ftoi_floor(v.x * 31.0f);
uint r = ftoi_trunc(v.x * 31.0f);
float r0 = float(((r+0) << 3) | ((r+0) >> 2));
float r1 = float(((r+1) << 3) | ((r+1) >> 2));
if (fabs(v.x - r1) < fabs(v.x - r0)) r = min(r+1, 31U);
r = (r << 3) | (r >> 2);
uint g = ftoi_floor(v.y * 63.0f);
uint g = ftoi_trunc(v.y * 63.0f);
float g0 = float(((g+0) << 2) | ((g+0) >> 4));
float g1 = float(((g+1) << 2) | ((g+1) >> 4));
if (fabs(v.y - g1) < fabs(v.y - g0)) g = min(g+1, 63U);
g = (g << 2) | (g >> 4);
uint b = ftoi_floor(v.z * 31.0f);
uint b = ftoi_trunc(v.z * 31.0f);
float b0 = float(((b+0) << 3) | ((b+0) >> 2));
float b1 = float(((b+1) << 3) | ((b+1) >> 2));
if (fabs(v.z - b1) < fabs(v.z - b0)) b = min(b+1, 31U);
@ -474,8 +474,10 @@ bool ClusterFit::compress3(Vector3 * start, Vector3 * end)
// clamp to the grid
a = clamp(a, 0, 1);
b = clamp(b, 0, 1);
//a = floor(grid * a + 0.5f) * gridrcp;
//b = floor(grid * b + 0.5f) * gridrcp;
#if 1
a = floor(grid * a + 0.5f) * gridrcp;
b = floor(grid * b + 0.5f) * gridrcp;
#else
//int ar = ftoi_round(31 * a.x); ar = (ar << 3) | (ar >> 2); a.x = float(ar) / 255.0f;
//int ag = ftoi_round(63 * a.y); ar = (ag << 2) | (ag >> 4); a.y = float(ag) / 255.0f;
@ -496,7 +498,7 @@ bool ClusterFit::compress3(Vector3 * start, Vector3 * end)
a = round565(a);
b = round565(b);
#endif
// compute the error
Vector3 e1 = a*a*alpha2_sum + b*b*beta2_sum + 2.0f*( a*b*alphabeta_sum - a*alphax_sum - b*betax_sum );
@ -582,9 +584,10 @@ bool ClusterFit::compress4(Vector3 * start, Vector3 * end)
// clamp to the grid
a = clamp(a, 0, 1);
b = clamp(b, 0, 1);
//a = floor(a * grid + 0.5f) * gridrcp;
//b = floor(b * grid + 0.5f) * gridrcp;
#if 0
a = floor(a * grid + 0.5f) * gridrcp;
b = floor(b * grid + 0.5f) * gridrcp;
#else
//int ar = ftoi_round(31 * a.x); ar = (ar << 3) | (ar >> 2); a.x = float(ar) / 255.0f;
//int ag = ftoi_round(63 * a.y); ar = (ag << 2) | (ag >> 4); a.y = float(ag) / 255.0f;
//int ab = ftoi_round(31 * a.z); ar = (ab << 3) | (ab >> 2); a.z = float(ab) / 255.0f;
@ -606,6 +609,8 @@ bool ClusterFit::compress4(Vector3 * start, Vector3 * end)
a = round565(a);
b = round565(b);
#endif
// @@ It would be much more accurate to evaluate the error exactly.
// compute the error
Vector3 e1 = a*a*alpha2_sum + b*b*beta2_sum + 2.0f*( a*b*alphabeta_sum - a*alphax_sum - b*betax_sum );

4
src/nvtt/ClusterFit.h
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@ -31,8 +31,8 @@
#include "nvmath/Vector.h"
// Use SIMD version if altivec or SSE are available.
//#define NVTT_USE_SIMD (NV_USE_ALTIVEC || NV_USE_SSE)
#define NVTT_USE_SIMD 0
#define NVTT_USE_SIMD (NV_USE_ALTIVEC || NV_USE_SSE)
//#define NVTT_USE_SIMD 0
namespace nv {

34
src/nvtt/CompressorDX9.cpp
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@ -113,9 +113,40 @@ void FastCompressorDXT5n::compressBlock(ColorBlock & rgba, nvtt::AlphaMode alpha
}
namespace nv {
float compress_dxt1(const Vector3 input_colors[16], const float input_weights[16], const Vector3 & color_weights, BlockDXT1 * output);
}
#if 1
void CompressorDXT1::compressBlock(ColorSet & set, nvtt::AlphaMode alphaMode, const nvtt::CompressionOptions::Private & compressionOptions, void * output)
{
#if 1
// @@ This setup is the same for all compressors.
Vector3 input_colors[16];
float input_weights[16];
uint x, y;
for (y = 0; y < set.h; y++) {
for (x = 0; x < set.w; x++) {
input_colors[4*y+x] = set.color(x, y).xyz();
input_weights[4*y+x] = 1.0f;
if (alphaMode == nvtt::AlphaMode_Transparency) input_weights[4*y+x] = set.color(x, y).z;
}
for (; x < 4; x++) {
input_colors[4*y+x] = Vector3(0);
input_weights[4*y+x] = 0.0f;
}
}
for (; y < 4; y++) {
for (x = 0; x < 4; x++) {
input_colors[4*y+x] = Vector3(0);
input_weights[4*y+x] = 0.0f;
}
}
compress_dxt1(input_colors, input_weights, compressionOptions.colorWeight.xyz(), (BlockDXT1 *)output);
#else
set.setUniformWeights();
set.createMinimalSet(/*ignoreTransparent*/false);
@ -145,8 +176,9 @@ void CompressorDXT1::compressBlock(ColorSet & set, nvtt::AlphaMode alphaMode, co
QuickCompress::outputBlock4(set, start, end, block);
}
}
#endif
}
#elif 1
#elif 0
extern void compress_dxt1_bounding_box_exhaustive(const ColorBlock & input, BlockDXT1 * output);

592
src/nvtt/CompressorDXT1.cpp
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@ -20,13 +20,81 @@
using namespace nv;
inline static void color_block_to_vector_block(const ColorBlock & rgba, Vector3 block[16])
{
for (int i = 0; i < 16; i++)
{
const Color32 c = rgba.color(i);
block[i] = Vector3(c.r, c.g, c.b);
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Color conversion functions.
static const float midpoints5[32] = {
0.015686f, 0.047059f, 0.078431f, 0.111765f, 0.145098f, 0.176471f, 0.207843f, 0.241176f, 0.274510f, 0.305882f, 0.337255f, 0.370588f, 0.403922f, 0.435294f, 0.466667f, 0.5f,
0.533333f, 0.564706f, 0.596078f, 0.629412f, 0.662745f, 0.694118f, 0.725490f, 0.758824f, 0.792157f, 0.823529f, 0.854902f, 0.888235f, 0.921569f, 0.952941f, 0.984314f, 1.0f
};
static const float midpoints6[64] = {
0.007843f, 0.023529f, 0.039216f, 0.054902f, 0.070588f, 0.086275f, 0.101961f, 0.117647f, 0.133333f, 0.149020f, 0.164706f, 0.180392f, 0.196078f, 0.211765f, 0.227451f, 0.245098f,
0.262745f, 0.278431f, 0.294118f, 0.309804f, 0.325490f, 0.341176f, 0.356863f, 0.372549f, 0.388235f, 0.403922f, 0.419608f, 0.435294f, 0.450980f, 0.466667f, 0.482353f, 0.500000f,
0.517647f, 0.533333f, 0.549020f, 0.564706f, 0.580392f, 0.596078f, 0.611765f, 0.627451f, 0.643137f, 0.658824f, 0.674510f, 0.690196f, 0.705882f, 0.721569f, 0.737255f, 0.754902f,
0.772549f, 0.788235f, 0.803922f, 0.819608f, 0.835294f, 0.850980f, 0.866667f, 0.882353f, 0.898039f, 0.913725f, 0.929412f, 0.945098f, 0.960784f, 0.976471f, 0.992157f, 1.0f
};
/*void init_tables() {
for (int i = 0; i < 31; i++) {
float f0 = float(((i+0) << 3) | ((i+0) >> 2)) / 255.0f;
float f1 = float(((i+1) << 3) | ((i+1) >> 2)) / 255.0f;
midpoints5[i] = (f0 + f1) * 0.5;
}
midpoints5[31] = 1.0f;
for (int i = 0; i < 63; i++) {
float f0 = float(((i+0) << 2) | ((i+0) >> 4)) / 255.0f;
float f1 = float(((i+1) << 2) | ((i+1) >> 4)) / 255.0f;
midpoints6[i] = (f0 + f1) * 0.5;
}
midpoints6[63] = 1.0f;
}*/
static Color16 vector3_to_color16(const Vector3 & v) {
// Truncate.
uint r = ftoi_trunc(clamp(v.x * 31.0f, 0.0f, 31.0f));
uint g = ftoi_trunc(clamp(v.y * 63.0f, 0.0f, 63.0f));
uint b = ftoi_trunc(clamp(v.z * 31.0f, 0.0f, 31.0f));
// Round exactly according to 565 bit-expansion.
r += (v.x > midpoints5[r]);
g += (v.y > midpoints6[g]);
b += (v.z > midpoints5[b]);
return Color16((r << 11) | (g << 5) | b);
}
static Color32 bitexpand_color16_to_color32(Color16 c16) {
Color32 c32;
//c32.b = (c16.b << 3) | (c16.b >> 2);
//c32.g = (c16.g << 2) | (c16.g >> 4);
//c32.r = (c16.r << 3) | (c16.r >> 2);
//c32.a = 0xFF;
c32.u = ((c16.u << 3) & 0xf8) | ((c16.u << 5) & 0xfc00) | ((c16.u << 8) & 0xf80000);
c32.u |= (c32.u >> 5) & 0x070007;
c32.u |= (c32.u >> 6) & 0x000300;
return c32;
}
static Color32 bitexpand_color16_to_color32(int r, int g, int b) {
Color32 c32;
c32.b = (b << 3) | (b >> 2);
c32.g = (g << 2) | (g >> 4);
c32.r = (r << 3) | (r >> 2);
c32.a = 0xFF;
return c32;
}
static Color16 truncate_color32_to_color16(Color32 c32) {
Color16 c16;
c16.b = (c32.b >> 3);
c16.g = (c32.g >> 2);
c16.r = (c32.r >> 3);
return c16;
}
inline Vector3 r5g6b5_to_vector3(int r, int g, int b)
@ -40,20 +108,32 @@ inline Vector3 r5g6b5_to_vector3(int r, int g, int b)
inline Vector3 color_to_vector3(Color32 c)
{
const float scale = 1.0f / 255.0f;
const float scale = 1.0f / 255.0f;
return Vector3(c.r * scale, c.g * scale, c.b * scale);
}
inline Color32 vector3_to_color(Vector3 v)
{
Color32 color;
color.r = U8(ftoi_round(saturate(v.x) * 255));
color.g = U8(ftoi_round(saturate(v.y) * 255));
color.b = U8(ftoi_round(saturate(v.z) * 255));
color.a = 255;
Color32 color;
color.r = U8(ftoi_round(saturate(v.x) * 255));
color.g = U8(ftoi_round(saturate(v.y) * 255));
color.b = U8(ftoi_round(saturate(v.z) * 255));
color.a = 255;
return color;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Input block processing.
inline static void color_block_to_vector_block(const ColorBlock & rgba, Vector3 block[16])
{
for (int i = 0; i < 16; i++)
{
const Color32 c = rgba.color(i);
block[i] = Vector3(c.r, c.g, c.b);
}
}
// Find first valid color.
static bool find_valid_color_rgb(const Vector3 * colors, const float * weights, int count, Vector3 * valid_color)
@ -114,46 +194,67 @@ static int reduce_colors(const Vector3 * input_colors, const float * input_weigh
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Error evaluation.
// Different ways of estimating the error.
static float evaluate_mse(const Vector3 & p, const Vector3 & c) {
return square(p.x-c.x) + square(p.y-c.y) + square(p.z-c.z);
/*static float evaluate_mse(const Vector3 & p, const Vector3 & c) {
//return (square(p.x-c.x) * w2.x + square(p.y-c.y) * w2.y + square(p.z-c.z) * w2.z);
Vector3 d = (p - c);
return dot(d, d);
}*/
static float evaluate_mse(const Vector3 & p, const Vector3 & c, const Vector3 & w) {
//return (square(p.x-c.x) * w2.x + square(p.y-c.y) * w2.y + square(p.z-c.z) * w2.z);
Vector3 d = (p - c) * w;
return dot(d, d);
}
/*static float evaluate_mse(const Vector3 & p, const Vector3 & c, const Vector3 & w) {
return ww.x * square(p.x-c.x) + ww.y * square(p.y-c.y) + ww.z * square(p.z-c.z);
}*/
static int evaluate_mse_rgb(const Color32 & p, const Color32 & c) {
return square(int(p.r)-c.r) + square(int(p.g)-c.g) + square(int(p.b)-c.b);
static int evaluate_mse(const Color32 & p, const Color32 & c) {
return (square(int(p.r)-c.r) + square(int(p.g)-c.g) + square(int(p.b)-c.b));
}
static float evaluate_mse(const Vector3 palette[4], const Vector3 & c) {
float e0 = evaluate_mse(palette[0], c);
float e1 = evaluate_mse(palette[1], c);
float e2 = evaluate_mse(palette[2], c);
float e3 = evaluate_mse(palette[3], c);
static float evaluate_mse(const Vector3 palette[4], const Vector3 & c, const Vector3 & w) {
float e0 = evaluate_mse(palette[0], c, w);
float e1 = evaluate_mse(palette[1], c, w);
float e2 = evaluate_mse(palette[2], c, w);
float e3 = evaluate_mse(palette[3], c, w);
return min(min(e0, e1), min(e2, e3));
}
static int evaluate_mse(const Color32 palette[4], const Color32 & c) {
int e0 = evaluate_mse_rgb(palette[0], c);
int e1 = evaluate_mse_rgb(palette[1], c);
int e2 = evaluate_mse_rgb(palette[2], c);
int e3 = evaluate_mse_rgb(palette[3], c);
int e0 = evaluate_mse(palette[0], c);
int e1 = evaluate_mse(palette[1], c);
int e2 = evaluate_mse(palette[2], c);
int e3 = evaluate_mse(palette[3], c);
return min(min(e0, e1), min(e2, e3));
}
static float evaluate_mse(const Vector3 palette[4], const Vector3 & c, int index) {
return evaluate_mse(palette[index], c);
}
// Returns MSE error in [0-255] range.
static int evaluate_mse(const BlockDXT1 * output, Color32 color, int index) {
Color32 palette[4];
output->evaluatePalette(palette, /*d3d9=*/false);
static int evaluate_mse(const Color32 palette[4], const Color32 & c, int index) {
return evaluate_mse_rgb(palette[index], c);
return evaluate_mse(palette[index], color);
}
// Returns weighted MSE error in [0-255] range.
static float evaluate_palette_error(Color32 palette[4], const Color32 * colors, const float * weights, int count) {
float total = 0.0f;
for (int i = 0; i < count; i++) {
total += weights[i] * evaluate_mse(palette, colors[i]);
}
return total;
}
static float evaluate_mse(const BlockDXT1 * output, Vector3 colors[16]) {
#if 0
static float evaluate_mse(const BlockDXT1 * output, const Vector3 colors[16]) {
Color32 palette[4];
output->evaluatePalette(palette, /*d3d9=*/false);
@ -167,39 +268,171 @@ static float evaluate_mse(const BlockDXT1 * output, Vector3 colors[16]) {
float error = 0.0f;
for (int i = 0; i < 16; i++) {
int index = (output->indices >> (2*i)) & 3; // @@ Is this the right order?
error += evaluate_mse(vector_palette, colors[i], index);
error += evaluate_mse(vector_palette[index], colors[i]);
}
return error;
}
#endif
static int evaluate_mse(const BlockDXT1 * output, Color32 color, int index) {
static float evaluate_mse(const Vector3 colors[16], const float weights[16], const Vector3 & color_weights, const BlockDXT1 * output) {
Color32 palette[4];
output->evaluatePalette(palette, /*d3d9=*/false);
return evaluate_mse(palette, color, index);
// convert palette to float.
Vector3 vector_palette[4];
for (int i = 0; i < 4; i++) {
vector_palette[i] = color_to_vector3(palette[i]);
}
// evaluate error for each index.
float error = 0.0f;
for (int i = 0; i < 16; i++) {
int index = (output->indices >> (2 * i)) & 3;
error += weights[i] * evaluate_mse(vector_palette[index], colors[i], color_weights);
}
return error;
}
/*void output_block3(const ColorSet & set, const Vector3 & start, const Vector3 & end, BlockDXT1 * block)
///////////////////////////////////////////////////////////////////////////////////////////////////
// Palette evaluation.
static void evaluate_palette4(Color32 palette[4]) {
palette[2].r = (2 * palette[0].r + palette[1].r) / 3;
palette[2].g = (2 * palette[0].g + palette[1].g) / 3;
palette[2].b = (2 * palette[0].b + palette[1].b) / 3;
palette[3].r = (2 * palette[1].r + palette[0].r) / 3;
palette[3].g = (2 * palette[1].g + palette[0].g) / 3;
palette[3].b = (2 * palette[1].b + palette[0].b) / 3;
}
static void evaluate_palette3(Color32 palette[4]) {
palette[2].r = (palette[0].r + palette[1].r) / 2;
palette[2].g = (palette[0].g + palette[1].g) / 2;
palette[2].b = (palette[0].b + palette[1].b) / 2;
palette[3].r = 0;
palette[3].g = 0;
palette[3].b = 0;
}
static void evaluate_palette(Color16 c0, Color16 c1, Color32 palette[4]) {
palette[0] = bitexpand_color16_to_color32(c0);
palette[1] = bitexpand_color16_to_color32(c1);
if (c0.u > c1.u) {
evaluate_palette4(palette);
}
else {
evaluate_palette3(palette);
}
}
static void evaluate_palette(Color16 c0, Color16 c1, Vector3 palette[4]) {
Color32 palette32[4];
evaluate_palette(c0, c1, palette32);
for (int i = 0; i < 4; i++) {
palette[i] = color_to_vector3(palette32[i]);
}
}
static void evaluate_palette3(Color16 c0, Color16 c1, Vector3 palette[4]) {
nvDebugCheck(c0.u > c1.u);
Color32 palette32[4];
evaluate_palette(c0, c1, palette32);
for (int i = 0; i < 4; i++) {
palette[i] = color_to_vector3(palette32[i]);
}
}
static uint compute_indices4(const Vector3 input_colors[16], const Vector3 & color_weights, const Vector3 palette[4]) {
uint indices = 0;
for (int i = 0; i < 16; i++) {
float d0 = evaluate_mse(palette[0], input_colors[i], color_weights);
float d1 = evaluate_mse(palette[1], input_colors[i], color_weights);
float d2 = evaluate_mse(palette[2], input_colors[i], color_weights);
float d3 = evaluate_mse(palette[3], input_colors[i], color_weights);
uint b0 = d0 > d3;
uint b1 = d1 > d2;
uint b2 = d0 > d2;
uint b3 = d1 > d3;
uint b4 = d2 > d3;
uint x0 = b1 & b2;
uint x1 = b0 & b3;
uint x2 = b0 & b4;
indices |= (x2 | ((x0 | x1) << 1)) << (2 * i);
}
return indices;
}
static uint compute_indices(const Vector3 input_colors[16], const Vector3 & color_weights, const Vector3 palette[4]) {
uint indices = 0;
for (int i = 0; i < 16; i++) {
float d0 = evaluate_mse(palette[0], input_colors[i], color_weights);
float d1 = evaluate_mse(palette[1], input_colors[i], color_weights);
float d2 = evaluate_mse(palette[2], input_colors[i], color_weights);
float d3 = evaluate_mse(palette[3], input_colors[i], color_weights);
uint index;
if (d0 < d1 && d0 < d2 && d0 < d3) index = 0;
else if (d1 < d2 && d1 < d3) index = 1;
else if (d2 < d3) index = 2;
else index = 3;
indices |= index << (2 * i);
}
return indices;
}
static void output_block3(const Vector3 input_colors[16], const Vector3 & color_weights, const Vector3 & v0, const Vector3 & v1, BlockDXT1 * block)
{
Vector3 minColor = start * 255.0f;
Vector3 maxColor = end * 255.0f;
uint16 color0 = roundAndExpand(&minColor);
uint16 color1 = roundAndExpand(&maxColor);
Color16 color0 = vector3_to_color16(v0);
Color16 color1 = vector3_to_color16(v1);
if (color0 > color1) {
swap(maxColor, minColor);
if (color0.u > color1.u) {
swap(color0, color1);
}
block->col0 = Color16(color0);
block->col1 = Color16(color1);
block->indices = compute_indices3(colors, weights, count, maxColor / 255.0f, minColor / 255.0f);
Vector3 palette[4];
evaluate_palette(color0, color1, palette);
//optimizeEndPoints3(set, block);
}*/
block->col0 = color0;
block->col1 = color1;
block->indices = compute_indices(input_colors, color_weights, palette);
}
static void output_block4(const Vector3 input_colors[16], const Vector3 & color_weights, const Vector3 & v0, const Vector3 & v1, BlockDXT1 * block)
{
Color16 color0 = vector3_to_color16(v0);
Color16 color1 = vector3_to_color16(v1);
if (color0.u < color1.u) {
swap(color0, color1);
}
Vector3 palette[4];
evaluate_palette(color0, color1, palette);
block->col0 = color0;
block->col1 = color1;
block->indices = compute_indices4(input_colors, color_weights, palette);
}
@ -207,7 +440,7 @@ static int evaluate_mse(const BlockDXT1 * output, Color32 color, int index) {
// Single color compressor, based on:
// https://mollyrocket.com/forums/viewtopic.php?t=392
float nv::compress_dxt1_single_color_optimal(Color32 c, BlockDXT1 * output)
static void compress_dxt1_single_color_optimal(Color32 c, BlockDXT1 * output)
{
output->col0.r = OMatch5[c.r][0];
output->col0.g = OMatch6[c.g][0];
@ -222,92 +455,66 @@ float nv::compress_dxt1_single_color_optimal(Color32 c, BlockDXT1 * output)
swap(output->col0.u, output->col1.u);
output->indices ^= 0x55555555;
}
return (float) evaluate_mse(output, c, output->indices & 3);
}
float nv::compress_dxt1_single_color_optimal(const Vector3 & color, BlockDXT1 * output)
{
return compress_dxt1_single_color_optimal(vector3_to_color(color), output);
}
// Low quality baseline compressor.
float nv::compress_dxt1_least_squares_fit(const Vector3 * input_colors, const Vector3 * colors, const float * weights, int count, BlockDXT1 * output)
float nv::compress_dxt1_single_color_optimal(Color32 c, BlockDXT1 * output)
{
// @@ Iterative best end point fit.
::compress_dxt1_single_color_optimal(c, output);
return FLT_MAX;
// Multiply by 16^2, the weight associated to a single color.
// Divide by 255*255 to covert error to [0-1] range.
return (256.0f / (255*255)) * evaluate_mse(output, c, output->indices & 3);
}
static Color32 bitexpand_color16_to_color32(Color16 c16) {
Color32 c32;
c32.b = (c16.b << 3) | (c16.b >> 2);
c32.g = (c16.g << 2) | (c16.g >> 4);
c32.r = (c16.r << 3) | (c16.r >> 2);
c32.a = 0xFF;
//c32.u = ((c16.u << 3) & 0xf8) | ((c16.u << 5) & 0xfc00) | ((c16.u << 8) & 0xf80000);
//c32.u |= (c32.u >> 5) & 0x070007;
//c32.u |= (c32.u >> 6) & 0x000300;
return c32;
float nv::compress_dxt1_single_color_optimal(const Vector3 & color, BlockDXT1 * output)
{
return compress_dxt1_single_color_optimal(vector3_to_color(color), output);
}
static Color32 bitexpand_color16_to_color32(int r, int g, int b) {
Color32 c32;
c32.b = (b << 3) | (b >> 2);
c32.g = (g << 2) | (g >> 4);
c32.r = (r << 3) | (r >> 2);
c32.a = 0xFF;
return c32;
}
static Color16 truncate_color32_to_color16(Color32 c32) {
Color16 c16;
c16.b = (c32.b >> 3);
c16.g = (c32.g >> 2);
c16.r = (c32.r >> 3);
return c16;
}
// Compress block using the average color.
float nv::compress_dxt1_single_color(const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, BlockDXT1 * output)
{
// Compute block average.
Vector3 color_sum(0);
float weight_sum = 0;
for (int i = 0; i < count; i++) {
color_sum += colors[i] * weights[i];
weight_sum += weights[i];
}
// Compress optimally.
::compress_dxt1_single_color_optimal(vector3_to_color(color_sum / weight_sum), output);
// Decompress block color.
Color32 palette[4];
output->evaluatePalette(palette, /*d3d9=*/false);
static float evaluate_palette4(Color32 palette[4]) {
palette[2].r = (2 * palette[0].r + palette[1].r) / 3;
palette[2].g = (2 * palette[0].g + palette[1].g) / 3;
palette[2].b = (2 * palette[0].b + palette[1].b) / 3;
palette[3].r = (2 * palette[1].r + palette[0].r) / 3;
palette[3].g = (2 * palette[1].g + palette[0].g) / 3;
palette[3].b = (2 * palette[1].b + palette[0].b) / 3;
}
Vector3 block_color = color_to_vector3(palette[output->indices & 0x3]);
static float evaluate_palette3(Color32 palette[4]) {
palette[2].r = (palette[0].r + palette[1].r) / 2;
palette[2].g = (palette[0].g + palette[1].g) / 2;
palette[2].b = (palette[0].b + palette[1].b) / 2;
palette[3].r = 0;
palette[3].g = 0;
palette[3].b = 0;
// Evaluate error.
float error = 0;
for (int i = 0; i < count; i++) {
error += weights[i] * evaluate_mse(block_color, colors[i], color_weights);
}
return error;
}
static float evaluate_palette_error(Color32 palette[4], const Color32 * colors, const float * weights, int count) {
float total = 0.0f;
for (int i = 0; i < count; i++) {
total += (weights[i] * weights[i]) * evaluate_mse(palette, colors[i]);
}
return total;
}
/* @@ Not implemented yet.
// Low quality baseline compressor.
float nv::compress_dxt1_least_squares_fit(const Vector3 * input_colors, const Vector3 * colors, const float * weights, int count, BlockDXT1 * output)
{
// @@ Iterative best end point fit.
return FLT_MAX;
}*/
float nv::compress_dxt1_bounding_box_exhaustive(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, int max_volume, BlockDXT1 * output)
float nv::compress_dxt1_bounding_box_exhaustive(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, int max_volume, BlockDXT1 * output)
{
// Compute bounding box.
Vector3 min_color(1.0f);
@ -331,85 +538,92 @@ float nv::compress_dxt1_bounding_box_exhaustive(const Vector3 input_colors[16],
int range_g = max_g - min_g;
int range_b = max_b - min_b;
min_r = max(0, min_r - (range_r + 1) / 1 - 1);
min_g = max(0, min_g - (range_g + 1) / 1 - 1);
min_b = max(0, min_b - (range_b + 1) / 1 - 1);
min_r = max(0, min_r - range_r / 2 - 2);
min_g = max(0, min_g - range_g / 2 - 2);
min_b = max(0, min_b - range_b / 2 - 2);
max_r = min(31, max_r + (range_r + 1) / 2 + 1);
max_g = min(63, max_g + (range_g + 1) / 2 + 1);
max_b = min(31, max_b + (range_b + 1) / 2 + 1);
max_r = min(31, max_r + range_r / 2 + 2);
max_g = min(63, max_g + range_g / 2 + 2);
max_b = min(31, max_b + range_b / 2 + 2);
// Estimate size of search space.
int volume = (max_r-min_r+1) * (max_g-min_g+1) * (max_b-min_b+1);
// if size under search_limit, then proceed. Note that search_limit is sqrt of number of evaluations.
// if size under search_limit, then proceed. Note that search_volume is sqrt of number of evaluations.
if (volume > max_volume) {
return FLT_MAX;
}
// @@ Convert to fixed point before building box?
Color32 colors32[16];
for (int i = 0; i < count; i++) {
colors32[i] = toColor32(Vector4(colors[i], 1));
}
float best_error = FLT_MAX;
Color32 best0, best1;
Color16 best0, best1; // @@ Record endpoints as Color16?
Color16 c0, c1;
Color32 palette[4];
for(int r0 = min_r; r0 <= max_r; r0++)
for(int r1 = max_r; r1 >= r0; r1--)
for(int g0 = min_g; g0 <= max_g; g0++)
for(int g1 = max_g; g1 >= g0; g1--)
for(int b0 = min_b; b0 <= max_b; b0++)
for(int b1 = max_b; b1 >= b0; b1--)
{
Color32 palette[4];
palette[0] = bitexpand_color16_to_color32(r1, g1, b1);
palette[1] = bitexpand_color16_to_color32(r0, g0, b0);
// Evaluate error in 4 color mode.
evaluate_palette4(palette);
c0.r = r0; c0.g = g0; c0.b = b0;
palette[0] = bitexpand_color16_to_color32(c0);
for(int r1 = min_r; r1 <= max_r; r1++)
for(int g1 = min_g; g1 <= max_g; g1++)
for(int b1 = min_b; b1 <= max_b; b1++)
{
c1.r = r1; c1.g = g1; c1.b = b1;
palette[1] = bitexpand_color16_to_color32(c1);
if (c0.u > c1.u) {
// Evaluate error in 4 color mode.
evaluate_palette4(palette);
}
else {
#if 1
// Evaluate error in 3 color mode.
evaluate_palette3(palette);
#else
// Skip 3 color mode.
continue;
#endif
}
float error = evaluate_palette_error(palette, colors32, weights, count);
float error = evaluate_palette_error(palette, colors32, weights, count);
if (error < best_error) {
best_error = error;
best0 = palette[0];
best1 = palette[1];
if (error < best_error) {
best_error = error;
best0 = c0;
best1 = c1;
}
}
}
#if 0
// Evaluate error in 3 color mode.
evaluate_palette3(palette);
float error = evaluate_palette_error(palette, colors, weights, count);
output->col0 = best0;
output->col1 = best1;
if (error < best_error) {
best_error = error;
best0 = palette[1];
best1 = palette[0];
}
#endif
if (output->col0.u < output->col1.u) {
int k = 1;
}
output->col0 = truncate_color32_to_color16(best0);
output->col1 = truncate_color32_to_color16(best1);
Vector3 vector_palette[4];
evaluate_palette(output->col0, output->col1, vector_palette);
if (output->col0.u <= output->col1.u) {
//output->indices = computeIndices3(colors, best0, best1);
}
else {
//output->indices = computeIndices4(colors, best0, best1);
}
output->indices = compute_indices(input_colors, color_weights, vector_palette);
return FLT_MAX;
return best_error / (255 * 255);
}
float nv::compress_dxt1_cluster_fit(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, BlockDXT1 * output)
void nv::compress_dxt1_cluster_fit(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, BlockDXT1 * output)
{
ClusterFit fit;
//fit.setColorWeights(compressionOptions.colorWeight);
fit.setColorWeights(Vector4(1)); // @@ Set color weights.
fit.setColorWeights(Vector4(color_weights, 1));
fit.setColorSet(colors, weights, count);
// start & end are in [0, 1] range.
@ -417,18 +631,17 @@ float nv::compress_dxt1_cluster_fit(const Vector3 input_colors[16], const Vector
fit.compress4(&start, &end);
if (fit.compress3(&start, &end)) {
//output_block3(input_colors, start, end, block);
// @@ Output block.
output_block3(input_colors, color_weights, start, end, output);
}
else {
//output_block4(input_colors, start, end, block);
// @@ Output block.
output_block4(input_colors, color_weights, start, end, output);
}
}
float nv::compress_dxt1(const Vector3 input_colors[16], const float input_weights[16], BlockDXT1 * output)
float nv::compress_dxt1(const Vector3 input_colors[16], const float input_weights[16], const Vector3 & color_weights, BlockDXT1 * output)
{
Vector3 colors[16];
float weights[16];
@ -442,20 +655,59 @@ float nv::compress_dxt1(const Vector3 input_colors[16], const float input_weight
return 0;
}
if (count == 1) {
return compress_dxt1_single_color_optimal(colors[0], output);
float error = FLT_MAX;
// Sometimes the single color compressor produces better results than the exhaustive. This introduces discontinuities between blocks that
// use different compressors. For this reason, this is not enabled by default.
if (1) {
error = compress_dxt1_single_color(colors, weights, count, color_weights, output);
if (error == 0.0f || count == 1) {
// Early out.
return error;
}
}
// This is too expensive, even with a low threshold.
// If high quality:
//error = compress_dxt1_bounding_box_exhaustive(colors, weigths, count, 3200, error, output);
//if (error < FLT_MAX) return error;
if (0) {
BlockDXT1 exhaustive_output;
float exhaustive_error = compress_dxt1_bounding_box_exhaustive(input_colors, colors, weights, count, color_weights, 400, &exhaustive_output);
if (exhaustive_error != FLT_MAX) {
float exhaustive_error2 = evaluate_mse(input_colors, input_weights, color_weights, &exhaustive_output);
// The exhaustive compressor does not use color_weights, so the results may be different.
//nvCheck(equal(exhaustive_error, exhaustive_error2));
if (exhaustive_error2 < error) {
*output = exhaustive_output;
error = exhaustive_error;
}
}
}
// @@ TODO.
// This is pretty fast and in some cases can produces better quality than cluster fit.
// error = compress_dxt1_least_squares_fit(colors, weigths, error, output);
//error = compress_dxt1_least_squares_fit(colors, weigths, error, output);
//
float error = compress_dxt1_cluster_fit(input_colors, colors, weights, count, output);
// Cluster fit cannot handle single color blocks, so encode them optimally if we haven't encoded them already.
if (error == FLT_MAX && count == 1) {
error = compress_dxt1_single_color_optimal(colors[0], output);
}
if (count > 1) {
BlockDXT1 cluster_fit_output;
compress_dxt1_cluster_fit(input_colors, colors, weights, count, color_weights, &cluster_fit_output);
float cluster_fit_error = evaluate_mse(input_colors, input_weights, color_weights, &cluster_fit_output);
if (cluster_fit_error < error) {
*output = cluster_fit_output;
error = cluster_fit_error;
}
}
return error;
}

9
src/nvtt/CompressorDXT1.h
Unescape Escape View File

@ -28,11 +28,12 @@ namespace nv {
float compress_dxt1_single_color_optimal(Color32 c, BlockDXT1 * output);
float compress_dxt1_single_color_optimal(const Vector3 & color, BlockDXT1 * output);
float compress_dxt1_least_squares_fit(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, BlockDXT1 * output);
float compress_dxt1_bounding_box_exhaustive(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, int search_limit, BlockDXT1 * output);
float compress_dxt1_cluster_fit(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, BlockDXT1 * output);
float compress_dxt1_single_color(const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, BlockDXT1 * output);
float compress_dxt1_least_squares_fit(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, BlockDXT1 * output);
float compress_dxt1_bounding_box_exhaustive(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, int search_limit, BlockDXT1 * output);
void compress_dxt1_cluster_fit(const Vector3 input_colors[16], const Vector3 * colors, const float * weights, int count, const Vector3 & color_weights, BlockDXT1 * output);
float compress_dxt1(const Vector3 colors[16], const float weights[16], BlockDXT1 * output);
float compress_dxt1(const Vector3 colors[16], const float weights[16], const Vector3 & color_weights, BlockDXT1 * output);
}
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