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FasTC/BPTCEncoder/src/BC7Compressor.cpp
Pavel Krajcevski af25b83356 Fix some more compiler warnings.
2013-01-29 17:37:20 -05:00

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/* FasTC
* Copyright (c) 2012 University of North Carolina at Chapel Hill. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its documentation for educational,
* research, and non-profit purposes, without fee, and without a written agreement is hereby granted,
* provided that the above copyright notice, this paragraph, and the following four paragraphs appear
* in all copies.
*
* Permission to incorporate this software into commercial products may be obtained by contacting the
* authors or the Office of Technology Development at the University of North Carolina at Chapel Hill <otd@unc.edu>.
*
* This software program and documentation are copyrighted by the University of North Carolina at Chapel Hill.
* The software program and documentation are supplied "as is," without any accompanying services from the
* University of North Carolina at Chapel Hill or the authors. The University of North Carolina at Chapel Hill
* and the authors do not warrant that the operation of the program will be uninterrupted or error-free. The
* end-user understands that the program was developed for research purposes and is advised not to rely
* exclusively on the program for any reason.
*
* IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE AUTHORS BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE
* USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE
* AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ANY
* STATUTORY WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY
* OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS HAVE NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
* ENHANCEMENTS, OR MODIFICATIONS.
*
* Please send all BUG REPORTS to <pavel@cs.unc.edu>.
*
* The authors may be contacted via:
*
* Pavel Krajcevski
* Dept of Computer Science
* 201 S Columbia St
* Frederick P. Brooks, Jr. Computer Science Bldg
* Chapel Hill, NC 27599-3175
* USA
*
* <http://gamma.cs.unc.edu/FasTC/>
*/
// The original lisence from the code available at the following location:
// http://software.intel.com/en-us/vcsource/samples/fast-texture-compression
//
// This code has been modified significantly from the original.
//--------------------------------------------------------------------------------------
// Copyright 2011 Intel Corporation
// All Rights Reserved
//
// Permission is granted to use, copy, distribute and prepare derivative works of this
// software for any purpose and without fee, provided, that the above copyright notice
// and this statement appear in all copies. Intel makes no representations about the
// suitability of this software for any purpose. THIS SOFTWARE IS PROVIDED "AS IS."
// INTEL SPECIFICALLY DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, AND ALL LIABILITY,
// INCLUDING CONSEQUENTIAL AND OTHER INDIRECT DAMAGES, FOR THE USE OF THIS SOFTWARE,
// INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PROPRIETARY RIGHTS, AND INCLUDING THE
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Intel does not
// assume any responsibility for any errors which may appear in this software nor any
// responsibility to update it.
//
//--------------------------------------------------------------------------------------
#include "TexCompTypes.h"
#include "BC7Compressor.h"
#include "BC7CompressionMode.h"
#include "BCLookupTables.h"
#include "RGBAEndpoints.h"
#include "BitStream.h"
#include "BlockStats.h"
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <cfloat>
#include <ctime>
#ifdef _MSC_VER
#define ALIGN_SSE __declspec( align(16) )
#else
#define ALIGN_SSE __attribute__((aligned(16)))
#endif
// #define USE_PCA_FOR_SHAPE_ESTIMATION
enum EBlockStats {
eBlockStat_Path,
eBlockStat_Mode,
eBlockStat_SingleShapeEstimate,
eBlockStat_TwoShapeEstimate,
eBlockStat_ThreeShapeEstimate,
eBlockStat_ModeZeroEstimate,
eBlockStat_ModeOneEstimate,
eBlockStat_ModeTwoEstimate,
eBlockStat_ModeThreeEstimate,
eBlockStat_ModeFourEstimate,
eBlockStat_ModeFiveEstimate,
eBlockStat_ModeSixEstimate,
eBlockStat_ModeSevenEstimate,
eBlockStat_ModeZeroError,
eBlockStat_ModeOneError,
eBlockStat_ModeTwoError,
eBlockStat_ModeThreeError,
eBlockStat_ModeFourError,
eBlockStat_ModeFiveError,
eBlockStat_ModeSixError,
eBlockStat_ModeSevenError,
kNumBlockStats
};
static const char *kBlockStatString[kNumBlockStats] = {
"BlockStat_Path",
"BlockStat_Mode",
"BlockStat_SingleShapeEstimate",
"BlockStat_TwoShapeEstimate",
"BlockStat_ThreeShapeEstimate",
"BlockStat_ModeZeroEstimate",
"BlockStat_ModeOneEstimate",
"BlockStat_ModeTwoEstimate",
"BlockStat_ModeThreeEstimate",
"BlockStat_ModeFourEstimate",
"BlockStat_ModeFiveEstimate",
"BlockStat_ModeSixEstimate",
"BlockStat_ModeSevenEstimate",
"BlockStat_ModeZeroError",
"BlockStat_ModeOneError",
"BlockStat_ModeTwoError",
"BlockStat_ModeThreeError",
"BlockStat_ModeFourError",
"BlockStat_ModeFiveError",
"BlockStat_ModeSixError",
"BlockStat_ModeSevenError",
};
static const uint32 kNumShapes2 = 64;
static const uint16 kShapeMask2[kNumShapes2] = {
0xcccc, 0x8888, 0xeeee, 0xecc8, 0xc880, 0xfeec, 0xfec8, 0xec80,
0xc800, 0xffec, 0xfe80, 0xe800, 0xffe8, 0xff00, 0xfff0, 0xf000,
0xf710, 0x008e, 0x7100, 0x08ce, 0x008c, 0x7310, 0x3100, 0x8cce,
0x088c, 0x3110, 0x6666, 0x366c, 0x17e8, 0x0ff0, 0x718e, 0x399c,
0xaaaa, 0xf0f0, 0x5a5a, 0x33cc, 0x3c3c, 0x55aa, 0x9696, 0xa55a,
0x73ce, 0x13c8, 0x324c, 0x3bdc, 0x6996, 0xc33c, 0x9966, 0x0660,
0x0272, 0x04e4, 0x4e40, 0x2720, 0xc936, 0x936c, 0x39c6, 0x639c,
0x9336, 0x9cc6, 0x817e, 0xe718, 0xccf0, 0x0fcc, 0x7744, 0xee22
};
static const int kAnchorIdx2[kNumShapes2] = {
15,15,15,15,15,15,15,15,
15,15,15,15,15,15,15,15,
15, 2, 8, 2, 2, 8, 8,15,
2, 8, 2, 2, 8, 8, 2, 2,
15,15, 6, 8, 2, 8,15,15,
2, 8, 2, 2, 2,15,15, 6,
6, 2, 6, 8,15,15, 2, 2,
15,15,15,15,15, 2, 2, 15
};
static const uint32 kNumShapes3 = 64;
static const uint16 kShapeMask3[kNumShapes3][2] = {
{ 0xfecc, 0xf600 }, { 0xffc8, 0x7300 }, { 0xff90, 0x3310 }, { 0xecce, 0x00ce }, { 0xff00, 0xcc00 }, { 0xcccc, 0xcc00 }, { 0xffcc, 0x00cc }, { 0xffcc, 0x3300 },
{ 0xff00, 0xf000 }, { 0xfff0, 0xf000 }, { 0xfff0, 0xff00 }, { 0xcccc, 0x8888 }, { 0xeeee, 0x8888 }, { 0xeeee, 0xcccc }, { 0xffec, 0xec80 }, { 0x739c, 0x7310 },
{ 0xfec8, 0xc800 }, { 0x39ce, 0x3100 }, { 0xfff0, 0xccc0 }, { 0xfccc, 0x0ccc }, { 0xeeee, 0xee00 }, { 0xff88, 0x7700 }, { 0xeec0, 0xcc00 }, { 0x7730, 0x3300 },
{ 0x0cee, 0x00cc }, { 0xffcc, 0xfc88 }, { 0x6ff6, 0x0660 }, { 0xff60, 0x6600 }, { 0xcbbc, 0xc88c }, { 0xf966, 0xf900 }, { 0xceec, 0x0cc0 }, { 0xff10, 0x7310 },
{ 0xff80, 0xec80 }, { 0xccce, 0x08ce }, { 0xeccc, 0xec80 }, { 0x6666, 0x4444 }, { 0x0ff0, 0x0f00 }, { 0x6db6, 0x4924 }, { 0x6bd6, 0x4294 }, { 0xcf3c, 0x0c30 },
{ 0xc3fc, 0x03c0 }, { 0xffaa, 0xff00 }, { 0xff00, 0x5500 }, { 0xfcfc, 0xcccc }, { 0xcccc, 0x0c0c }, { 0xf6f6, 0x6666 }, { 0xaffa, 0x0ff0 }, { 0xfff0, 0x5550 },
{ 0xfaaa, 0xf000 }, { 0xeeee, 0x0e0e }, { 0xf8f8, 0x8888 }, { 0xfff0, 0x9990 }, { 0xeeee, 0xe00e }, { 0x8ff8, 0x8888 }, { 0xf666, 0xf000 }, { 0xff00, 0x9900 },
{ 0xff66, 0xff00 }, { 0xcccc, 0xc00c }, { 0xcffc, 0xcccc }, { 0xf000, 0x9000 }, { 0x8888, 0x0808 }, { 0xfefe, 0xeeee }, { 0xfffa, 0xfff0 }, { 0x7bde, 0x7310 }
};
static const uint32 kWMValues[] = { 0x32b92180, 0x32ba3080, 0x31103200, 0x28103c80, 0x32bb3080, 0x25903600, 0x3530b900, 0x3b32b180, 0x34b5b980 };
static const uint32 kNumWMVals = sizeof(kWMValues) / sizeof(kWMValues[0]);
static uint32 gWMVal = -1;
static const int kAnchorIdx3[2][kNumShapes3] = {
{ 3, 3,15,15, 8, 3,15,15,
8, 8, 6, 6, 6, 5, 3, 3,
3, 3, 8,15, 3, 3, 6,10,
5, 8, 8, 6, 8, 5,15,15,
8,15, 3, 5, 6,10, 8,15,
15, 3,15, 5,15,15,15,15,
3,15, 5, 5, 5, 8, 5,10,
5,10, 8,13,15,12, 3, 3 },
{ 15, 8, 8, 3,15,15, 3, 8,
15,15,15,15,15,15,15, 8,
15, 8,15, 3,15, 8,15, 8,
3,15, 6,10,15,15,10, 8,
15, 3,15,10,10, 8, 9,10,
6,15, 8,15, 3, 6, 6, 8,
15, 3,15,15,15,15,15,15,
15,15,15,15, 3,15,15, 8 }
};
template <typename T>
static inline T sad(const T &a, const T &b) {
return (a > b)? a - b : b - a;
}
static uint8 GetSubsetForIndex(int idx, const int shapeIdx, const int nSubsets) {
int subset = 0;
switch(nSubsets) {
case 2:
{
subset = !!((1 << idx) & kShapeMask2[shapeIdx]);
}
break;
case 3:
{
if(1 << idx & kShapeMask3[shapeIdx][0])
subset = 1 + !!((1 << idx) & kShapeMask3[shapeIdx][1]);
else
subset = 0;
}
break;
default:
break;
}
return subset;
}
static uint32 GetAnchorIndexForSubset(int subset, const int shapeIdx, const int nSubsets) {
int anchorIdx = 0;
switch(subset) {
case 1:
{
if(nSubsets == 2) {
anchorIdx = kAnchorIdx2[shapeIdx];
}
else {
anchorIdx = kAnchorIdx3[0][shapeIdx];
}
}
break;
case 2:
{
assert(nSubsets == 3);
anchorIdx = kAnchorIdx3[1][shapeIdx];
}
break;
default:
break;
}
return anchorIdx;
}
template <typename T>
static T min(const T &a, const T &b) {
return (a < b)? a : b;
}
template <typename T>
static T max(const T &a, const T &b) {
return (a > b)? a : b;
}
template <typename T>
static void insert(T* buf, int bufSz, T newVal, int idx = 0) {
int safeIdx = min(bufSz-1, max(idx, 0));
for(int i = bufSz - 1; i > safeIdx; i--) {
buf[i] = buf[i-1];
}
buf[safeIdx] = newVal;
}
template <typename T>
static inline void swap(T &a, T &b) { T t = a; a = b; b = t; }
const uint32 kBC7InterpolationValues[4][16][2] = {
{ {64, 0}, {33, 31}, {0, 64}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0} },
{ {64, 0}, {43, 21}, {21, 43}, {0, 64}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0} },
{ {64, 0}, {55, 9}, {46, 18}, {37, 27}, {27, 37}, {18, 46}, {9, 55}, {0, 64}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0} },
{ {64, 0}, {60, 4}, {55, 9}, {51, 13}, {47, 17}, {43, 21}, {38, 26}, {34, 30}, {30, 34}, {26, 38}, {21, 43}, {17, 47}, {13, 51}, {9, 55}, {4, 60}, {0, 64} }
};
int BC7CompressionMode::MaxAnnealingIterations = 50; // This is a setting.
BC7CompressionMode::Attributes BC7CompressionMode::kModeAttributes[kNumModes] = {
{ 0, 4, 3, 3, 0, 4, 0, false, false, BC7CompressionMode::ePBitType_NotShared },
{ 1, 6, 2, 3, 0, 6, 0, false, false, BC7CompressionMode::ePBitType_Shared },
{ 2, 6, 3, 2, 0, 5, 0, false, false, BC7CompressionMode::ePBitType_None },
{ 3, 6, 2, 2, 0, 7, 0, false, false, BC7CompressionMode::ePBitType_NotShared },
{ 4, 0, 1, 2, 3, 5, 6, true, true, BC7CompressionMode::ePBitType_None },
{ 5, 0, 1, 2, 2, 7, 8, true, false, BC7CompressionMode::ePBitType_None },
{ 6, 0, 1, 4, 0, 7, 7, false, false, BC7CompressionMode::ePBitType_NotShared },
{ 7, 6, 2, 2, 0, 5, 5, false, false, BC7CompressionMode::ePBitType_NotShared },
};
void BC7CompressionMode::ClampEndpointsToGrid(RGBAVector &p1, RGBAVector &p2, int &bestPBitCombo) const {
const int nPbitCombos = GetNumPbitCombos();
const bool hasPbits = nPbitCombos > 1;
const uint32 qmask = GetQuantizationMask();
ClampEndpoints(p1, p2);
// !SPEED! This can be faster.
float minDist = FLT_MAX;
RGBAVector bp1, bp2;
for(int i = 0; i < nPbitCombos; i++) {
uint32 qp1, qp2;
if(hasPbits) {
qp1 = p1.ToPixel(qmask, GetPBitCombo(i)[0]);
qp2 = p2.ToPixel(qmask, GetPBitCombo(i)[1]);
}
else {
qp1 = p1.ToPixel(qmask);
qp2 = p2.ToPixel(qmask);
}
uint8 *pqp1 = (uint8 *)&qp1;
uint8 *pqp2 = (uint8 *)&qp2;
RGBAVector np1 = RGBAVector(float(pqp1[0]), float(pqp1[1]), float(pqp1[2]), float(pqp1[3]));
RGBAVector np2 = RGBAVector(float(pqp2[0]), float(pqp2[1]), float(pqp2[2]), float(pqp2[3]));
RGBAVector d1 = np1 - p1;
RGBAVector d2 = np2 - p2;
float dist = (d1 * d1) + (d2 * d2);
if(dist < minDist) {
minDist = dist;
bp1 = np1; bp2 = np2;
bestPBitCombo = i;
}
}
p1 = bp1;
p2 = bp2;
}
double BC7CompressionMode::CompressSingleColor(const RGBAVector &p, RGBAVector &p1, RGBAVector &p2, int &bestPbitCombo) const {
const uint32 pixel = p.ToPixel();
uint32 bestDist = 0xFF;
bestPbitCombo = -1;
for(int pbi = 0; pbi < GetNumPbitCombos(); pbi++) {
const int *pbitCombo = GetPBitCombo(pbi);
uint32 dist = 0x0;
uint32 bestValI[kNumColorChannels] = { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
uint32 bestValJ[kNumColorChannels] = { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
for(uint32 ci = 0; ci < kNumColorChannels; ci++) {
const uint8 val = (pixel >> (ci * 8)) & 0xFF;
int nBits = ci == 3? GetAlphaChannelPrecision() : m_Attributes->colorChannelPrecision;
// If we don't handle this channel, then we don't need to
// worry about how well we interpolate.
if(nBits == 0) { bestValI[ci] = bestValJ[ci] = 0xFF; continue; }
const int nPossVals = (1 << nBits);
int possValsH[256];
int possValsL[256];
// Do we have a pbit?
const bool havepbit = GetPBitType() != ePBitType_None;
if(havepbit)
nBits++;
for(int i = 0; i < nPossVals; i++) {
int vh = i, vl = i;
if(havepbit) {
vh <<= 1;
vl <<= 1;
vh |= pbitCombo[1];
vl |= pbitCombo[0];
}
possValsH[i] = (vh << (8 - nBits));
possValsH[i] |= (possValsH[i] >> nBits);
possValsL[i] = (vl << (8 - nBits));
possValsL[i] |= (possValsL[i] >> nBits);
}
const uint32 interpVal0 = kBC7InterpolationValues[GetNumberOfBitsPerIndex() - 1][1][0];
const uint32 interpVal1 = kBC7InterpolationValues[GetNumberOfBitsPerIndex() - 1][1][1];
// Find the closest interpolated val that to the given val...
uint32 bestChannelDist = 0xFF;
for(int i = 0; bestChannelDist > 0 && i < nPossVals; i++)
for(int j = 0; bestChannelDist > 0 && j < nPossVals; j++) {
const uint32 v1 = possValsL[i];
const uint32 v2 = possValsH[j];
const uint32 combo = (interpVal0*v1 + (interpVal1 * v2) + 32) >> 6;
const uint32 err = (combo > val)? combo - val : val - combo;
if(err < bestChannelDist) {
bestChannelDist = err;
bestValI[ci] = v1;
bestValJ[ci] = v2;
}
}
dist = max(bestChannelDist, dist);
}
if(dist < bestDist) {
bestDist = dist;
bestPbitCombo = pbi;
for(uint32 ci = 0; ci < kNumColorChannels; ci++) {
p1.c[ci] = float(bestValI[ci]);
p2.c[ci] = float(bestValJ[ci]);
}
}
}
return bestDist;
}
// Fast random number generator. See more information at
// http://software.intel.com/en-us/articles/fast-random-number-generator-on-the-intel-pentiumr-4-processor/
static uint32 g_seed = uint32(time(NULL));
static inline uint32 fastrand() {
g_seed = (214013 * g_seed + 2531011);
return (g_seed>>16) & RAND_MAX;
}
static const int kNumStepDirections = 8;
static const RGBADir kStepDirections[kNumStepDirections] = {
// For pBit changes, we have 8 possible directions.
RGBADir(RGBAVector(1.0f, 1.0f, 1.0f, 0.0f)),
RGBADir(RGBAVector(-1.0f, 1.0f, 1.0f, 0.0f)),
RGBADir(RGBAVector(1.0f, -1.0f, 1.0f, 0.0f)),
RGBADir(RGBAVector(-1.0f, -1.0f, 1.0f, 0.0f)),
RGBADir(RGBAVector(1.0f, 1.0f, -1.0f, 0.0f)),
RGBADir(RGBAVector(-1.0f, 1.0f, -1.0f, 0.0f)),
RGBADir(RGBAVector(1.0f, -1.0f, -1.0f, 0.0f)),
RGBADir(RGBAVector(-1.0f, -1.0f, -1.0f, 0.0f))
};
static void ChangePointForDirWithoutPbitChange(RGBAVector &v, int dir, const float step[kNumColorChannels]) {
if(dir % 2) {
v.x -= step[0];
}
else {
v.x += step[0];
}
if(((dir / 2) % 2)) {
v.y -= step[1];
}
else {
v.y += step[1];
}
if(((dir / 4) % 2)) {
v.z -= step[2];
}
else {
v.z += step[2];
}
if(((dir / 8) % 2)) {
v.a -= step[3];
}
else {
v.a += step[3];
}
}
static void ChangePointForDirWithPbitChange(RGBAVector &v, int dir, int oldPbit, const float step[kNumColorChannels]) {
if(dir % 2 && oldPbit == 0) {
v.x -= step[0];
}
else if(!(dir % 2) && oldPbit == 1) {
v.x += step[0];
}
if(((dir / 2) % 2) && oldPbit == 0) {
v.y -= step[1];
}
else if(!((dir / 2) % 2) && oldPbit == 1) {
v.y += step[1];
}
if(((dir / 4) % 2) && oldPbit == 0) {
v.z -= step[2];
}
else if(!((dir / 4) % 2) && oldPbit == 1) {
v.z += step[2];
}
if(((dir / 8) % 2) && oldPbit == 0) {
v.a -= step[3];
}
else if(!((dir / 8) % 2) && oldPbit == 1) {
v.a += step[3];
}
}
void BC7CompressionMode::PickBestNeighboringEndpoints(const RGBACluster &cluster, const RGBAVector &p1, const RGBAVector &p2, const int curPbitCombo, RGBAVector &np1, RGBAVector &np2, int &nPbitCombo, const VisitedState *visitedStates, int nVisited, float stepSz) const {
// !SPEED! There might be a way to make this faster since we're working
// with floating point values that are powers of two. We should be able
// to just set the proper bits in the exponent and leave the mantissa to 0.
float step[kNumColorChannels] = {
stepSz * float(1 << (8 - m_Attributes->colorChannelPrecision)),
stepSz * float(1 << (8 - m_Attributes->colorChannelPrecision)),
stepSz * float(1 << (8 - m_Attributes->colorChannelPrecision)),
stepSz * float(1 << (8 - GetAlphaChannelPrecision()))
};
if(m_IsOpaque) {
step[(GetRotationMode() + 3) % kNumColorChannels] = 0.0f;
}
// First, let's figure out the new pbit combo... if there's no pbit then we don't need
// to worry about it.
const bool hasPbits = GetPBitType() != ePBitType_None;
if(hasPbits) {
// If there is a pbit, then we must change it, because those will provide the closest values
// to the current point.
if(GetPBitType() == ePBitType_Shared)
nPbitCombo = (curPbitCombo + 1) % 2;
else {
// Not shared... p1 needs to change and p2 needs to change... which means that
// combo 0 gets rotated to combo 3, combo 1 gets rotated to combo 2 and vice
// versa...
nPbitCombo = 3 - curPbitCombo;
}
assert(GetPBitCombo(curPbitCombo)[0] + GetPBitCombo(nPbitCombo)[0] == 1);
assert(GetPBitCombo(curPbitCombo)[1] + GetPBitCombo(nPbitCombo)[1] == 1);
}
bool visited = true;
int infLoopPrevent = -1;
while(visited && ++infLoopPrevent < 16) {
for(int pt = 0; pt < 2; pt++) {
const RGBAVector &p = (pt)? p1 : p2;
RGBAVector &np = (pt)? np1 : np2;
np = p;
if(hasPbits)
ChangePointForDirWithPbitChange(np, fastrand() % 16, GetPBitCombo(curPbitCombo)[pt], step);
else
ChangePointForDirWithoutPbitChange(np, fastrand() % 16, step);
for(uint32 i = 0; i < kNumColorChannels; i++) {
np.c[i] = min(max(np.c[i], 0.0f), 255.0f);
}
}
visited = false;
for(int i = 0; i < nVisited; i++) {
visited = visited || (
visitedStates[i].p1 == np1 &&
visitedStates[i].p2 == np2 &&
visitedStates[i].pBitCombo == nPbitCombo
);
}
}
}
// Fast generation of floats between 0 and 1. It generates a float
// whose exponent forces the value to be between 1 and 2, then it
// populates the mantissa with a random assortment of bits, and returns
// the bytes interpreted as a float. This prevents two things: 1, a
// division, and 2, a cast from an integer to a float.
#define COMPILE_ASSERT(x) extern int __compile_assert_[(int)(x)];
COMPILE_ASSERT(RAND_MAX == 0x7FFF)
static inline float frand() {
const uint16 r = fastrand();
// RAND_MAX is 0x7FFF, which offers 15 bits
// of precision. Therefore, we move the bits
// into the top of the 23 bit mantissa, and
// repeat the most significant bits of r in
// the least significant of the mantissa
const uint32 m = (r << 8) | (r >> 7);
const union {
uint32 fltAsInt;
float flt;
} fltUnion = { (127 << 23) | m };
return fltUnion.flt - 1.0f;
}
bool BC7CompressionMode::AcceptNewEndpointError(double newError, double oldError, float temp) const {
// Always accept better endpoints.
if(newError < oldError)
return true;
const double p = exp((0.1f * (oldError - newError)) / temp);
const double r = frand();
return r < p;
}
double BC7CompressionMode::OptimizeEndpointsForCluster(const RGBACluster &cluster, RGBAVector &p1, RGBAVector &p2, int *bestIndices, int &bestPbitCombo) const {
const int nBuckets = (1 << GetNumberOfBitsPerIndex());
const uint32 qmask = GetQuantizationMask();
// Here we use simulated annealing to traverse the space of clusters to find the best possible endpoints.
double curError = cluster.QuantizedError(p1, p2, nBuckets, qmask, GetErrorMetric(), GetPBitCombo(bestPbitCombo), bestIndices);
int curPbitCombo = bestPbitCombo;
double bestError = curError;
// Clamp endpoints to the grid...
uint32 qp1, qp2;
if(GetPBitType() != ePBitType_None) {
qp1 = p1.ToPixel(qmask, GetPBitCombo(bestPbitCombo)[0]);
qp2 = p2.ToPixel(qmask, GetPBitCombo(bestPbitCombo)[1]);
}
else {
qp1 = p1.ToPixel(qmask);
qp2 = p2.ToPixel(qmask);
}
uint8 *pqp1 = (uint8 *)&qp1;
uint8 *pqp2 = (uint8 *)&qp2;
p1 = RGBAVector(float(pqp1[0]), float(pqp1[1]), float(pqp1[2]), float(pqp1[3]));
p2 = RGBAVector(float(pqp2[0]), float(pqp2[1]), float(pqp2[2]), float(pqp2[3]));
RGBAVector bp1 = p1, bp2 = p2;
assert(curError == cluster.QuantizedError(p1, p2, nBuckets, qmask, GetErrorMetric(), GetPBitCombo(bestPbitCombo)));
int lastVisitedState = 0;
VisitedState visitedStates[kMaxAnnealingIterations];
visitedStates[lastVisitedState].p1 = p1;
visitedStates[lastVisitedState].p2 = p2;
visitedStates[lastVisitedState].pBitCombo = curPbitCombo;
lastVisitedState++;
const int maxEnergy = MaxAnnealingIterations;
for(int energy = 0; bestError > 0 && energy < maxEnergy; energy++) {
float temp = float(energy) / float(maxEnergy-1);
int indices[kMaxNumDataPoints];
RGBAVector np1, np2;
int nPbitCombo = 0;
PickBestNeighboringEndpoints(cluster, p1, p2, curPbitCombo, np1, np2, nPbitCombo, visitedStates, lastVisitedState);
double error = cluster.QuantizedError(np1, np2, nBuckets, qmask, GetErrorMetric(), GetPBitCombo(nPbitCombo), indices);
if(AcceptNewEndpointError(error, curError, temp)) {
curError = error;
p1 = np1;
p2 = np2;
curPbitCombo = nPbitCombo;
}
if(error < bestError) {
memcpy(bestIndices, indices, sizeof(indices));
bp1 = np1;
bp2 = np2;
bestPbitCombo = nPbitCombo;
bestError = error;
lastVisitedState = 0;
visitedStates[lastVisitedState].p1 = np1;
visitedStates[lastVisitedState].p2 = np2;
visitedStates[lastVisitedState].pBitCombo = nPbitCombo;
lastVisitedState++;
// Restart...
energy = 0;
}
}
p1 = bp1;
p2 = bp2;
return bestError;
}
double BC7CompressionMode::CompressCluster(const RGBACluster &cluster, RGBAVector &p1, RGBAVector &p2, int *bestIndices, int *alphaIndices) const {
assert(GetModeNumber() == 4 || GetModeNumber() == 5);
assert(GetNumberOfSubsets() == 1);
assert(cluster.GetNumPoints() == kMaxNumDataPoints);
assert(m_Attributes->alphaChannelPrecision > 0);
// If all the points are the same in the cluster, then we need to figure out what the best
// approximation to this point is....
if(cluster.AllSamePoint()) {
assert(!"We should only be using this function in modes 4 & 5 that have a single subset, in which case single colors should have been detected much earlier.");
const RGBAVector &p = cluster.GetPoint(0);
int dummyPbit = 0;
double bestErr = CompressSingleColor(p, p1, p2, dummyPbit);
// We're assuming all indices will be index 1...
for(uint32 i = 0; i < cluster.GetNumPoints(); i++) {
bestIndices[i] = 1;
alphaIndices[i] = 1;
}
return bestErr;
}
RGBACluster rgbCluster;
float alphaVals[kMaxNumDataPoints] = {0};
float alphaMin = FLT_MAX, alphaMax = -FLT_MAX;
for(uint32 i = 0; i < cluster.GetNumPoints(); i++) {
RGBAVector v = cluster.GetPoint(i);
switch(GetRotationMode()) {
default:
case 0:
// Do nothing
break;
case 1:
swap(v.r, v.a);
break;
case 2:
swap(v.g, v.a);
break;
case 3:
swap(v.b, v.a);
break;
}
alphaVals[i] = v.a;
v.a = 255.0f;
alphaMin = min(alphaVals[i], alphaMin);
alphaMax = max(alphaVals[i], alphaMax);
rgbCluster.AddPoint(v);
}
int dummyPbit = 0;
RGBAVector rgbp1, rgbp2;
double rgbError = CompressCluster(rgbCluster, rgbp1, rgbp2, bestIndices, dummyPbit);
float a1 = alphaMin, a2 = alphaMax;
double alphaError = DBL_MAX;
typedef uint32 tInterpPair[2];
typedef tInterpPair tInterpLevel[16];
const tInterpLevel *interpVals = kBC7InterpolationValues + (GetNumberOfBitsPerAlpha() - 1);
const float weight = GetErrorMetric().a;
const uint32 nBuckets = (1 << GetNumberOfBitsPerAlpha());
// If they're the same, then we can get them exactly.
if(a1 == a2)
{
const uint8 a1be = uint8(a1);
const uint8 a2be = uint8(a2);
// Mode 5 has 8 bits of precision for alpha.
if(GetModeNumber() == 5) {
for(uint32 i = 0; i < kMaxNumDataPoints; i++)
alphaIndices[i] = 0;
alphaError = 0.0;
}
else {
assert(GetModeNumber() == 4);
// Mode 4 can be treated like the 6 channel of DXT1 compression.
if(Optimal6CompressDXT1[a1be][0][0]) {
a1 = float((Optimal6CompressDXT1[a1be][1][1] << 2) | (Optimal6CompressDXT1[a1be][0][1] >> 4));
a2 = float((Optimal6CompressDXT1[a2be][1][2] << 2) | (Optimal6CompressDXT1[a2be][0][1] >> 4));
}
else {
a1 = float((Optimal6CompressDXT1[a1be][0][1] << 2) | (Optimal6CompressDXT1[a1be][0][1] >> 4));
a2 = float((Optimal6CompressDXT1[a2be][0][2] << 2) | (Optimal6CompressDXT1[a2be][0][1] >> 4));
}
if(m_IndexMode == 1) {
for(uint32 i = 0; i < kMaxNumDataPoints; i++)
alphaIndices[i] = 1;
}
else {
for(uint32 i = 0; i < kMaxNumDataPoints; i++)
alphaIndices[i] = 2;
}
uint32 interp0 = (*interpVals)[alphaIndices[0] & 0xFF][0];
uint32 interp1 = (*interpVals)[alphaIndices[0] & 0xFF][1];
const uint8 ip = (((uint32(a1) * interp0) + (uint32(a2) * interp1) + 32) >> 6) & 0xFF;
float pxError = weight * float((a1be > ip)? a1be - ip : ip - a1be);
pxError *= pxError;
alphaError = 16 * pxError;
}
}
else {
float vals[1<<3];
memset(vals, 0, sizeof(vals));
uint32 buckets[kMaxNumDataPoints];
// Figure out initial positioning.
for(uint32 i = 0; i < nBuckets; i++) {
vals[i] = alphaMin + (float(i)/float(nBuckets-1)) * (alphaMax - alphaMin);
}
// Assign each value to a bucket
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
float minDist = 255.0f;
for(uint32 j = 0; j < nBuckets; j++) {
float dist = fabs(alphaVals[i] - vals[j]);
if(dist < minDist) {
minDist = dist;
buckets[i] = j;
}
}
}
float npts[1 << 3];
// Do k-means
bool fixed = false;
while(!fixed) {
memset(npts, 0, sizeof(npts));
float avg[1 << 3];
memset(avg, 0, sizeof(avg));
// Calculate average of each cluster
for(uint32 i = 0; i < nBuckets; i++) {
for(uint32 j = 0; j < kMaxNumDataPoints; j++) {
if(buckets[j] == i) {
avg[i] += alphaVals[j];
npts[i] += 1.0f;
}
}
if(npts[i] > 0.0f)
avg[i] /= npts[i];
}
// Did we change anything?
fixed = true;
for(uint32 i = 0; i < nBuckets; i++) {
fixed = fixed && (avg[i] == vals[i]);
}
// Reassign indices...
memcpy(vals, avg, sizeof(vals));
// Reassign each value to a bucket
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
float minDist = 255.0f;
for(uint32 j = 0; j < nBuckets; j++) {
float dist = fabs(alphaVals[i] - vals[j]);
if(dist < minDist) {
minDist = dist;
buckets[i] = j;
}
}
}
}
// Do least squares fit of vals.
float asq = 0.0, bsq = 0.0, ab = 0.0;
float ax(0.0), bx(0.0);
for(uint32 i = 0; i < nBuckets; i++) {
float a = float(nBuckets - 1 - i) / float(nBuckets - 1);
float b = float(i) / float(nBuckets - 1);
float n = npts[i];
float x = vals[i];
asq += n * a * a;
bsq += n * b * b;
ab += n * a * b;
ax += x * a * n;
bx += x * b * n;
}
float f = 1.0f / (asq * bsq - ab * ab);
a1 = f * (ax * bsq - bx * ab);
a2 = f * (bx * asq - ax * ab);
// Clamp
a1 = min(255.0f, max(0.0f, a1));
a2 = min(255.0f, max(0.0f, a2));
// Quantize
const uint8 a1b = ::QuantizeChannel(uint8(a1), (((char)0x80) >> (GetAlphaChannelPrecision() - 1)));
const uint8 a2b = ::QuantizeChannel(uint8(a2), (((char)0x80) >> (GetAlphaChannelPrecision() - 1)));
// Compute error
alphaError = 0.0;
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
uint8 val = uint8(alphaVals[i]);
float minError = FLT_MAX;
int bestBucket = -1;
for(uint32 j = 0; j < nBuckets; j++) {
uint32 interp0 = (*interpVals)[j][0];
uint32 interp1 = (*interpVals)[j][1];
const uint8 ip = (((uint32(a1b) * interp0) + (uint32(a2b) * interp1) + 32) >> 6) & 0xFF;
float pxError = weight * float((val > ip)? val - ip : ip - val);
pxError *= pxError;
if(pxError < minError) {
minError = pxError;
bestBucket = j;
}
}
alphaError += minError;
alphaIndices[i] = bestBucket;
}
}
for(uint32 i = 0; i < kNumColorChannels; i++) {
p1.c[i] = (i == (kNumColorChannels-1))? a1 : rgbp1.c[i];
p2.c[i] = (i == (kNumColorChannels-1))? a2 : rgbp2.c[i];
}
return rgbError + alphaError;
}
double BC7CompressionMode::CompressCluster(const RGBACluster &cluster, RGBAVector &p1, RGBAVector &p2, int *bestIndices, int &bestPbitCombo) const {
// If all the points are the same in the cluster, then we need to figure out what the best
// approximation to this point is....
if(cluster.AllSamePoint()) {
const RGBAVector &p = cluster.GetPoint(0);
double bestErr = CompressSingleColor(p, p1, p2, bestPbitCombo);
// We're assuming all indices will be index 1...
for(uint32 i = 0; i < cluster.GetNumPoints(); i++) {
bestIndices[i] = 1;
}
return bestErr;
}
const uint32 nBuckets = (1 << GetNumberOfBitsPerIndex());
#if 1
RGBAVector avg = cluster.GetTotal() / float(cluster.GetNumPoints());
RGBADir axis;
double eigOne;
::GetPrincipalAxis(cluster.GetNumPoints(), cluster.GetPoints(), axis, eigOne, NULL);
float mindp = FLT_MAX, maxdp = -FLT_MAX;
for(uint32 i = 0 ; i < cluster.GetNumPoints(); i++) {
float dp = (cluster.GetPoint(i) - avg) * axis;
if(dp < mindp) mindp = dp;
if(dp > maxdp) maxdp = dp;
}
p1 = avg + mindp * axis;
p2 = avg + maxdp * axis;
#else
cluster.GetBoundingBox(p1, p2);
#endif
ClampEndpoints(p1, p2);
RGBAVector pts[1 << 4]; // At most 4 bits per index.
uint32 numPts[1<<4];
assert(nBuckets <= 1 << 4);
for(uint32 i = 0; i < nBuckets; i++) {
float s = (float(i) / float(nBuckets - 1));
pts[i] = (1.0f - s) * p1 + s * p2;
}
assert(pts[0] == p1);
assert(pts[nBuckets - 1] == p2);
// Do k-means clustering...
uint32 bucketIdx[kMaxNumDataPoints] = {0};
bool fixed = false;
while(!fixed) {
RGBAVector newPts[1 << 4];
// Assign each of the existing points to one of the buckets...
for(uint32 i = 0; i < cluster.GetNumPoints(); i++) {
int minBucket = -1;
float minDist = FLT_MAX;
for(uint32 j = 0; j < nBuckets; j++) {
RGBAVector v = cluster.GetPoint(i) - pts[j];
float distSq = v * v;
if(distSq < minDist)
{
minDist = distSq;
minBucket = j;
}
}
assert(minBucket >= 0);
bucketIdx[i] = minBucket;
}
// Calculate new buckets based on centroids of clusters...
for(uint32 i = 0; i < nBuckets; i++) {
numPts[i] = 0;
newPts[i] = RGBAVector(0.0f);
for(uint32 j = 0; j < cluster.GetNumPoints(); j++) {
if(bucketIdx[j] == i) {
numPts[i]++;
newPts[i] += cluster.GetPoint(j);
}
}
// If there are no points in this cluster, then it should
// remain the same as last time and avoid a divide by zero.
if(0 != numPts[i])
newPts[i] /= float(numPts[i]);
}
// If we haven't changed, then we're done.
fixed = true;
for(uint32 i = 0; i < nBuckets; i++) {
if(pts[i] != newPts[i])
fixed = false;
}
// Assign the new points to be the old points.
for(uint32 i = 0; i < nBuckets; i++) {
pts[i] = newPts[i];
}
}
// If there's only one bucket filled, then just compress for that single color...
int numBucketsFilled = 0, lastFilledBucket = -1;
for(uint32 i = 0; i < nBuckets; i++) {
if(numPts[i] > 0) {
numBucketsFilled++;
lastFilledBucket = i;
}
}
assert(numBucketsFilled > 0);
if(1 == numBucketsFilled) {
const RGBAVector &p = pts[lastFilledBucket];
double bestErr = CompressSingleColor(p, p1, p2, bestPbitCombo);
// We're assuming all indices will be index 1...
for(uint32 i = 0; i < cluster.GetNumPoints(); i++) {
bestIndices[i] = 1;
}
return bestErr;
}
// Now that we know the index of each pixel, we can assign the endpoints based on a least squares fit
// of the clusters. For more information, take a look at this article by NVidia:
// http://developer.download.nvidia.com/compute/cuda/1.1-Beta/x86_website/projects/dxtc/doc/cuda_dxtc.pdf
float asq = 0.0, bsq = 0.0, ab = 0.0;
RGBAVector ax(0.0), bx(0.0);
for(uint32 i = 0; i < nBuckets; i++) {
float a = float(nBuckets - 1 - i) / float(nBuckets - 1);
float b = float(i) / float(nBuckets - 1);
int n = numPts[i];
RGBAVector x = pts[i];
asq += float(n) * a * a;
bsq += float(n) * b * b;
ab += float(n) * a * b;
ax += x * a * float(n);
bx += x * b * float(n);
}
float f = 1.0f / (asq * bsq - ab * ab);
p1 = f * (ax * bsq - bx * ab);
p2 = f * (bx * asq - ax * ab);
ClampEndpointsToGrid(p1, p2, bestPbitCombo);
#ifdef _DEBUG
int pBitCombo = bestPbitCombo;
RGBAVector tp1 = p1, tp2 = p2;
ClampEndpointsToGrid(tp1, tp2, pBitCombo);
assert(p1 == tp1);
assert(p2 == tp2);
assert(pBitCombo == bestPbitCombo);
#endif
assert(bestPbitCombo >= 0);
return OptimizeEndpointsForCluster(cluster, p1, p2, bestIndices, bestPbitCombo);
}
double BC7CompressionMode::Compress(BitStream &stream, const int shapeIdx, const RGBACluster *clusters) {
const int kModeNumber = GetModeNumber();
const int nPartitionBits = GetNumberOfPartitionBits();
const int nSubsets = GetNumberOfSubsets();
// Mode #
stream.WriteBits(1 << kModeNumber, kModeNumber + 1);
// Partition #
assert((((1 << nPartitionBits) - 1) & shapeIdx) == shapeIdx);
stream.WriteBits(shapeIdx, nPartitionBits);
RGBAVector p1[kMaxNumSubsets], p2[kMaxNumSubsets];
int bestIndices[kMaxNumSubsets][kMaxNumDataPoints] = {
{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },
{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 },
{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 }
};
int bestAlphaIndices[kMaxNumDataPoints] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 };
int bestPbitCombo[kMaxNumSubsets] = { -1, -1, -1 };
int bestRotationMode = -1, bestIndexMode = -1;
double totalErr = 0.0;
for(int cidx = 0; cidx < nSubsets; cidx++) {
int indices[kMaxNumDataPoints] = {0};
if(m_Attributes->hasRotation) {
assert(nSubsets == 1);
int alphaIndices[kMaxNumDataPoints];
double bestError = DBL_MAX;
for(int rotMode = 0; rotMode < 4; rotMode++) {
SetRotationMode(rotMode);
const int nIdxModes = kModeNumber == 4? 2 : 1;
for(int idxMode = 0; idxMode < nIdxModes; idxMode++) {
SetIndexMode(idxMode);
RGBAVector v1, v2;
double error = CompressCluster(clusters[cidx], v1, v2, indices, alphaIndices);
if(error < bestError) {
bestError = error;
memcpy(bestIndices[cidx], indices, sizeof(indices));
memcpy(bestAlphaIndices, alphaIndices, sizeof(alphaIndices));
bestRotationMode = rotMode;
bestIndexMode = idxMode;
p1[cidx] = v1;
p2[cidx] = v2;
}
}
}
totalErr += bestError;
}
else {
// Compress this cluster
totalErr += CompressCluster(clusters[cidx], p1[cidx], p2[cidx], indices, bestPbitCombo[cidx]);
// Map the indices to their proper position.
int idx = 0;
for(int i = 0; i < 16; i++) {
int subs = GetSubsetForIndex(i, shapeIdx, GetNumberOfSubsets());
if(subs == cidx) {
bestIndices[cidx][i] = indices[idx++];
}
}
}
}
stream.WriteBits(bestRotationMode, m_Attributes->hasRotation? 2 : 0);
stream.WriteBits(bestIndexMode, m_Attributes->hasIdxMode? 1 : 0);
#ifdef _DEBUG
for(int i = 0; i < kMaxNumDataPoints; i++) {
int nSet = 0;
for(int j = 0; j < nSubsets; j++) {
if(bestIndices[j][i] >= 0)
nSet++;
}
assert(nSet == 1);
}
#endif
// Get the quantization mask
const uint32 qmask = GetQuantizationMask();
//Quantize the points...
uint32 pixel1[kMaxNumSubsets], pixel2[kMaxNumSubsets];
for(int i = 0; i < nSubsets; i++) {
switch(GetPBitType()) {
default:
case ePBitType_None:
pixel1[i] = p1[i].ToPixel(qmask);
pixel2[i] = p2[i].ToPixel(qmask);
break;
case ePBitType_Shared:
case ePBitType_NotShared:
pixel1[i] = p1[i].ToPixel(qmask, GetPBitCombo(bestPbitCombo[i])[0]);
pixel2[i] = p2[i].ToPixel(qmask, GetPBitCombo(bestPbitCombo[i])[1]);
break;
}
}
// If the anchor index does not have 0 in the leading bit, then
// we need to swap EVERYTHING.
for(int sidx = 0; sidx < nSubsets; sidx++) {
int anchorIdx = GetAnchorIndexForSubset(sidx, shapeIdx, nSubsets);
assert(bestIndices[sidx][anchorIdx] != -1);
const int nAlphaIndexBits = GetNumberOfBitsPerAlpha(bestIndexMode);
const int nIndexBits = GetNumberOfBitsPerIndex(bestIndexMode);
if(bestIndices[sidx][anchorIdx] >> (nIndexBits - 1)) {
uint32 t = pixel1[sidx]; pixel1[sidx] = pixel2[sidx]; pixel2[sidx] = t;
int nIndexVals = 1 << nIndexBits;
for(int i = 0; i < 16; i++) {
bestIndices[sidx][i] = (nIndexVals - 1) - bestIndices[sidx][i];
}
int nAlphaIndexVals = 1 << nAlphaIndexBits;
if(m_Attributes->hasRotation) {
for(int i = 0; i < 16; i++) {
bestAlphaIndices[i] = (nAlphaIndexVals - 1) - bestAlphaIndices[i];
}
}
}
if(m_Attributes->hasRotation && bestAlphaIndices[anchorIdx] >> (nAlphaIndexBits - 1)) {
uint8 * bp1 = (uint8 *)(&pixel1[sidx]);
uint8 * bp2 = (uint8 *)(&pixel2[sidx]);
uint8 t = bp1[3]; bp1[3] = bp2[3]; bp2[3] = t;
int nAlphaIndexVals = 1 << nAlphaIndexBits;
for(int i = 0; i < 16; i++) {
bestAlphaIndices[i] = (nAlphaIndexVals - 1) - bestAlphaIndices[i];
}
}
assert(!(bestIndices[sidx][anchorIdx] >> (nIndexBits - 1)));
assert(!m_Attributes->hasRotation || !(bestAlphaIndices[anchorIdx] >> (nAlphaIndexBits - 1)));
}
// Get the quantized values...
uint8 r1[kMaxNumSubsets], g1[kMaxNumSubsets], b1[kMaxNumSubsets], a1[kMaxNumSubsets];
uint8 r2[kMaxNumSubsets], g2[kMaxNumSubsets], b2[kMaxNumSubsets], a2[kMaxNumSubsets];
for(int i = 0; i < nSubsets; i++) {
r1[i] = pixel1[i] & 0xFF;
r2[i] = pixel2[i] & 0xFF;
g1[i] = (pixel1[i] >> 8) & 0xFF;
g2[i] = (pixel2[i] >> 8) & 0xFF;
b1[i] = (pixel1[i] >> 16) & 0xFF;
b2[i] = (pixel2[i] >> 16) & 0xFF;
a1[i] = (pixel1[i] >> 24) & 0xFF;
a2[i] = (pixel2[i] >> 24) & 0xFF;
}
// Write them out...
const int nRedBits = m_Attributes->colorChannelPrecision;
for(int i = 0; i < nSubsets; i++) {
stream.WriteBits(r1[i] >> (8 - nRedBits), nRedBits);
stream.WriteBits(r2[i] >> (8 - nRedBits), nRedBits);
}
const int nGreenBits = m_Attributes->colorChannelPrecision;
for(int i = 0; i < nSubsets; i++) {
stream.WriteBits(g1[i] >> (8 - nGreenBits), nGreenBits);
stream.WriteBits(g2[i] >> (8 - nGreenBits), nGreenBits);
}
const int nBlueBits = m_Attributes->colorChannelPrecision;
for(int i = 0; i < nSubsets; i++) {
stream.WriteBits(b1[i] >> (8 - nBlueBits), nBlueBits);
stream.WriteBits(b2[i] >> (8 - nBlueBits), nBlueBits);
}
const int nAlphaBits = m_Attributes->alphaChannelPrecision;
for(int i = 0; i < nSubsets; i++) {
stream.WriteBits(a1[i] >> (8 - nAlphaBits), nAlphaBits);
stream.WriteBits(a2[i] >> (8 - nAlphaBits), nAlphaBits);
}
// Write out the best pbits..
if(GetPBitType() != ePBitType_None) {
for(int s = 0; s < nSubsets; s++) {
const int *pbits = GetPBitCombo(bestPbitCombo[s]);
stream.WriteBits(pbits[0], 1);
if(GetPBitType() != ePBitType_Shared)
stream.WriteBits(pbits[1], 1);
}
}
// If our index mode has changed, then we need to write the alpha indices first.
if(m_Attributes->hasIdxMode && bestIndexMode == 1) {
assert(m_Attributes->hasRotation);
for(int i = 0; i < 16; i++) {
const int idx = bestAlphaIndices[i];
assert(GetAnchorIndexForSubset(0, shapeIdx, nSubsets) == 0);
assert(GetNumberOfBitsPerAlpha(bestIndexMode) == 2);
assert(idx >= 0 && idx < (1 << 2));
assert(i != 0 || !(idx >> 1) || !"Leading bit of anchor index is not zero!");
stream.WriteBits(idx, (i == 0)? 1 : 2);
}
for(int i = 0; i < 16; i++) {
const int idx = bestIndices[0][i];
assert(GetSubsetForIndex(i, shapeIdx, nSubsets) == 0);
assert(GetAnchorIndexForSubset(0, shapeIdx, nSubsets) == 0);
assert(GetNumberOfBitsPerIndex(bestIndexMode) == 3);
assert(idx >= 0 && idx < (1 << 3));
assert(i != 0 || !(idx >> 2) || !"Leading bit of anchor index is not zero!");
stream.WriteBits(idx, (i == 0)? 2 : 3);
}
}
else {
for(int i = 0; i < 16; i++) {
const int subs = GetSubsetForIndex(i, shapeIdx, nSubsets);
const int idx = bestIndices[subs][i];
const int anchorIdx = GetAnchorIndexForSubset(subs, shapeIdx, nSubsets);
const int nBitsForIdx = GetNumberOfBitsPerIndex(bestIndexMode);
assert(idx >= 0 && idx < (1 << nBitsForIdx));
assert(i != anchorIdx || !(idx >> (nBitsForIdx - 1)) || !"Leading bit of anchor index is not zero!");
stream.WriteBits(idx, (i == anchorIdx)? nBitsForIdx - 1 : nBitsForIdx);
}
if(m_Attributes->hasRotation) {
for(int i = 0; i < 16; i++) {
const int idx = bestAlphaIndices[i];
const int anchorIdx = 0;
const int nBitsForIdx = GetNumberOfBitsPerAlpha(bestIndexMode);
assert(idx >= 0 && idx < (1 << nBitsForIdx));
assert(i != anchorIdx || !(idx >> (nBitsForIdx - 1)) || !"Leading bit of anchor index is not zero!");
stream.WriteBits(idx, (i == anchorIdx)? nBitsForIdx - 1 : nBitsForIdx);
}
}
}
assert(stream.GetBitsWritten() == 128);
return totalErr;
}
namespace BC7C
{
static ErrorMetric gErrorMetric = eErrorMetric_Uniform;
void SetErrorMetric(ErrorMetric e) { gErrorMetric = e; }
ALIGN_SSE const float kErrorMetrics[kNumErrorMetrics][kNumColorChannels] = {
{ 1.0f, 1.0f, 1.0f, 1.0f },
{ sqrtf(0.3f), sqrtf(0.56f), sqrtf(0.11f), 1.0f }
};
const float *GetErrorMetric() { return kErrorMetrics[GetErrorMetricEnum()]; }
ErrorMetric GetErrorMetricEnum() { return gErrorMetric; }
// Function prototypes
static void CompressBC7Block(const uint32 *block, uint8 *outBuf);
static void CompressBC7Block(const uint32 *block, uint8 *outBuf, BlockStatManager &statManager);
static int gQualityLevel = 50;
void SetQualityLevel(int q) {
gQualityLevel = max(0, q);
}
int GetQualityLevel() { return gQualityLevel; }
// Returns true if the entire block is a single color.
static bool AllOneColor(const uint32 block[16]) {
const uint32 pixel = block[0];
for(int i = 1; i < 16; i++) {
if( block[i] != pixel )
return false;
}
return true;
}
// Write out a transparent block.
static void WriteTransparentBlock(BitStream &stream) {
// Use mode 6
stream.WriteBits(1 << 6, 7);
stream.WriteBits(0, 128-7);
assert(stream.GetBitsWritten() == 128);
}
// Compresses a single color optimally and outputs the result.
static void CompressOptimalColorBC7(uint32 pixel, BitStream &stream) {
stream.WriteBits(1 << 5, 6); // Mode 5
stream.WriteBits(0, 2); // No rotation bits.
uint8 r = pixel & 0xFF;
uint8 g = (pixel >> 8) & 0xFF;
uint8 b = (pixel >> 16) & 0xFF;
uint8 a = (pixel >> 24) & 0xFF;
// Red endpoints
stream.WriteBits(Optimal7CompressBC7Mode5[r][0], 7);
stream.WriteBits(Optimal7CompressBC7Mode5[r][1], 7);
// Green endpoints
stream.WriteBits(Optimal7CompressBC7Mode5[g][0], 7);
stream.WriteBits(Optimal7CompressBC7Mode5[g][1], 7);
// Blue endpoints
stream.WriteBits(Optimal7CompressBC7Mode5[b][0], 7);
stream.WriteBits(Optimal7CompressBC7Mode5[b][1], 7);
// Alpha endpoints... are just the same.
stream.WriteBits(a, 8);
stream.WriteBits(a, 8);
// Color indices are 1 for each pixel...
// Anchor index is 0, so 1 bit for the first pixel, then
// 01 for each following pixel giving the sequence of 31 bits:
// ...010101011
stream.WriteBits(0xaaaaaaab, 31);
// Alpha indices...
stream.WriteBits(kWMValues[gWMVal = (gWMVal+1) % kNumWMVals], 31);
}
static void DecompressBC7Block(const uint8 block[16], uint32 outBuf[16]);
// Compress an image using BC7 compression. Use the inBuf parameter to point to an image in
// 4-byte RGBA format. The width and height parameters specify the size of the image in pixels.
// The buffer pointed to by outBuf should be large enough to store the compressed image. This
// implementation has an 4:1 compression ratio.
void CompressImageBC7(const unsigned char *inBuf, unsigned char *outBuf, unsigned int width, unsigned int height)
{
const int kMaxIters = BC7CompressionMode::kMaxAnnealingIterations;
BC7CompressionMode::MaxAnnealingIterations = min(kMaxIters, GetQualityLevel());
for(uint32 j = 0; j < height; j += 4)
{
for(uint32 i = 0; i < width; i += 4)
{
// ExtractBlock(inBuf + i * 4, width, block);
CompressBC7Block((const uint32 *)inBuf, outBuf);
#ifndef NDEBUG
uint8 *block = (uint8 *)outBuf;
uint32 unComp[16];
DecompressBC7Block(block, unComp);
uint8* unCompData = (uint8 *)unComp;
double diffSum = 0.0;
for(int i = 0; i < 64; i+=4) {
double rdiff = sad(unCompData[i], inBuf[i]);
double gdiff = sad(unCompData[i+1], inBuf[i+1]);
double bdiff = sad(unCompData[i+2], inBuf[i+2]);
double adiff = sad(unCompData[i+3], inBuf[i+3]);
diffSum += (rdiff + gdiff + bdiff + adiff) * ((unCompData[i+3] + inBuf[i+3])*0.5);
}
double blockError = double(diffSum) / 64.0;
if(blockError > 50.0) {
fprintf(stderr, "WARNING: Block error very high (%.2f)\n", blockError);
}
#endif
outBuf += 16;
inBuf += 64;
}
}
}
void CompressImageBC7Stats(
const unsigned char *inBuf,
unsigned char *outBuf,
unsigned int width,
unsigned int height,
BlockStatManager &statManager
) {
const int kMaxIters = BC7CompressionMode::kMaxAnnealingIterations;
BC7CompressionMode::MaxAnnealingIterations = min(kMaxIters, GetQualityLevel());
for(uint32 j = 0; j < height; j += 4)
{
for(uint32 i = 0; i < width; i += 4)
{
// ExtractBlock(inBuf + i * 4, width, block);
CompressBC7Block((const uint32 *)inBuf, outBuf, statManager);
#ifndef NDEBUG
uint8 *block = (uint8 *)outBuf;
uint32 unComp[16];
DecompressBC7Block(block, unComp);
uint8* unCompData = (uint8 *)unComp;
int diffSum = 0;
for(int i = 0; i < 64; i++) {
diffSum += sad(unCompData[i], inBuf[i]);
}
double blockError = double(diffSum) / 64.0;
if(blockError > 50.0) {
fprintf(stderr, "WARNING: Block error very high (%.2f)\n", blockError);
}
#endif
outBuf += 16;
inBuf += 64;
}
}
}
static double CompressTwoClusters(
int shapeIdx,
const RGBACluster *clusters,
uint8 *outBuf,
bool opaque,
double *errors = NULL,
int *modeChosen = NULL
) {
uint8 tempBuf1[16];
BitStream tmpStream1(tempBuf1, 128, 0);
BC7CompressionMode compressor1(1, opaque);
double bestError = compressor1.Compress(tmpStream1, shapeIdx, clusters);
if(errors) errors[1] = bestError;
if(modeChosen) *modeChosen = 1;
memcpy(outBuf, tempBuf1, 16);
if(bestError == 0.0) {
return 0.0;
}
uint8 tempBuf3[16];
BitStream tmpStream3(tempBuf3, 128, 0);
BC7CompressionMode compressor3(3, opaque);
double error = compressor3.Compress(tmpStream3, shapeIdx, clusters);
if(errors) errors[3] = error;
if(error < bestError) {
if(modeChosen) *modeChosen = 3;
bestError = error;
memcpy(outBuf, tempBuf3, 16);
if(bestError == 0.0) {
return 0.0;
}
}
// Mode 3 offers more precision for RGB data. Mode 7 is really only if we have alpha.
if(!opaque)
{
uint8 tempBuf7[16];
BitStream tmpStream7(tempBuf7, 128, 0);
BC7CompressionMode compressor7(7, opaque);
error = compressor7.Compress(tmpStream7, shapeIdx, clusters);
if(errors) errors[7] = error;
if(error < bestError) {
if(modeChosen) *modeChosen = 7;
memcpy(outBuf, tempBuf7, 16);
return error;
}
}
return bestError;
}
static double CompressThreeClusters(
int shapeIdx,
const RGBACluster *clusters,
uint8 *outBuf,
bool opaque,
double *errors = NULL,
int *modeChosen = NULL
) {
uint8 tempBuf0[16];
BitStream tmpStream0(tempBuf0, 128, 0);
uint8 tempBuf2[16];
BitStream tmpStream2(tempBuf2, 128, 0);
BC7CompressionMode compressor0(0, opaque);
BC7CompressionMode compressor2(2, opaque);
double error, bestError;
if(shapeIdx < 16) {
bestError = compressor0.Compress(tmpStream0, shapeIdx, clusters);
if(errors) errors[0] = bestError;
}
else {
bestError = DBL_MAX;
if(errors) errors[0] = -1.0;
}
if(modeChosen) *modeChosen = 0;
memcpy(outBuf, tempBuf0, 16);
if(bestError == 0.0) {
return 0.0;
}
error = compressor2.Compress(tmpStream2, shapeIdx, clusters);
if(errors) errors[2] = error;
if(error < bestError) {
if(modeChosen) *modeChosen = 2;
memcpy(outBuf, tempBuf2, 16);
return error;
}
return bestError;
}
static void PopulateTwoClustersForShape(const RGBACluster &points, int shapeIdx, RGBACluster *clusters) {
const uint16 shape = kShapeMask2[shapeIdx];
for(uint32 pt = 0; pt < kMaxNumDataPoints; pt++) {
const RGBAVector &p = points.GetPoint(pt);
if((1 << pt) & shape)
clusters[1].AddPoint(p);
else
clusters[0].AddPoint(p);
}
assert(!(clusters[0].GetPointBitString() & clusters[1].GetPointBitString()));
assert((clusters[0].GetPointBitString() ^ clusters[1].GetPointBitString()) == 0xFFFF);
assert((shape & clusters[1].GetPointBitString()) == shape);
}
static void PopulateThreeClustersForShape(const RGBACluster &points, int shapeIdx, RGBACluster *clusters) {
for(uint32 pt = 0; pt < kMaxNumDataPoints; pt++) {
const RGBAVector &p = points.GetPoint(pt);
if((1 << pt) & kShapeMask3[shapeIdx][0]) {
if((1 << pt) & kShapeMask3[shapeIdx][1])
clusters[2].AddPoint(p);
else
clusters[1].AddPoint(p);
}
else
clusters[0].AddPoint(p);
}
assert(!(clusters[0].GetPointBitString() & clusters[1].GetPointBitString()));
assert(!(clusters[2].GetPointBitString() & clusters[1].GetPointBitString()));
assert(!(clusters[0].GetPointBitString() & clusters[2].GetPointBitString()));
}
static double EstimateTwoClusterError(RGBACluster &c) {
RGBAVector Min, Max, v;
c.GetBoundingBox(Min, Max);
v = Max - Min;
if(v * v == 0) {
return 0.0;
}
const float *w = BC7C::GetErrorMetric();
double error = 0.0001;
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
double eigOne = c.GetPrincipalEigenvalue();
double eigTwo = c.GetSecondEigenvalue();
if(eigOne != 0.0) {
error += eigTwo / eigOne;
}
else {
error += 1.0;
}
#else
error += c.QuantizedError(Min, Max, 8, 0xFFFFFFFF, RGBAVector(w[0], w[1], w[2], w[3]));
#endif
return error;
}
static double EstimateThreeClusterError(RGBACluster &c) {
RGBAVector Min, Max, v;
c.GetBoundingBox(Min, Max);
v = Max - Min;
if(v * v == 0) {
return 0.0;
}
const float *w = BC7C::GetErrorMetric();
double error = 0.0001;
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
double eigOne = c.GetPrincipalEigenvalue();
double eigTwo = c.GetSecondEigenvalue();
if(eigOne != 0.0) {
error += eigTwo / eigOne;
}
else {
error += 1.0;
}
#else
error += c.QuantizedError(Min, Max, 4, 0xFFFFFFFF, RGBAVector(w[0], w[1], w[2], w[3]));
#endif
return error;
}
static void CompressBC7Block(const uint32 *block, uint8 *outBuf) {
// All a single color?
if(AllOneColor(block)) {
BitStream bStrm(outBuf, 128, 0);
CompressOptimalColorBC7(*block, bStrm);
return;
}
RGBACluster blockCluster;
bool opaque = true;
bool transparent = true;
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
RGBAVector p = RGBAVector(i, block[i]);
blockCluster.AddPoint(p);
if(fabs(p.a - 255.0f) > 1e-10)
opaque = false;
if(p.a > 0.0f)
transparent = false;
}
// The whole block is transparent?
if(transparent) {
BitStream bStrm(outBuf, 128, 0);
WriteTransparentBlock(bStrm);
return;
}
// First we must figure out which shape to use. To do this, simply
// see which shape has the smallest sum of minimum bounding spheres.
double bestError[2] = { DBL_MAX, DBL_MAX };
int bestShapeIdx[2] = { -1, -1 };
RGBACluster bestClusters[2][3];
for(unsigned int i = 0; i < kNumShapes2; i++)
{
RGBACluster clusters[2];
PopulateTwoClustersForShape(blockCluster, i, clusters);
double err = 0.0;
for(int ci = 0; ci < 2; ci++) {
err += EstimateTwoClusterError(clusters[ci]);
}
// If it's small, we'll take it!
if(err < 1e-9) {
CompressTwoClusters(i, clusters, outBuf, opaque);
return;
}
if(err < bestError[0]) {
bestError[0] = err;
bestShapeIdx[0] = i;
bestClusters[0][0] = clusters[0];
bestClusters[0][1] = clusters[1];
}
}
// There are not 3 subset blocks that support alpha, so only check these
// if the entire block is opaque.
if(opaque) {
for(unsigned int i = 0; i < kNumShapes3; i++) {
RGBACluster clusters[3];
PopulateThreeClustersForShape(blockCluster, i, clusters);
double err = 0.0;
for(int ci = 0; ci < 3; ci++) {
err += EstimateThreeClusterError(clusters[ci]);
}
// If it's small, we'll take it!
if(err < 1e-9) {
CompressThreeClusters(i, clusters, outBuf, opaque);
return;
}
if(err < bestError[1]) {
bestError[1] = err;
bestShapeIdx[1] = i;
bestClusters[1][0] = clusters[0];
bestClusters[1][1] = clusters[1];
bestClusters[1][2] = clusters[2];
}
}
}
uint8 tempBuf1[16], tempBuf2[16];
BitStream tempStream1 (tempBuf1, 128, 0);
BC7CompressionMode compressor(6, opaque);
double best = compressor.Compress(tempStream1, 0, &blockCluster);
if(best == 0.0f) {
memcpy(outBuf, tempBuf1, 16);
return;
}
// Check modes 4 and 5 if the block isn't opaque...
if(!opaque) {
for(int mode = 4; mode <= 5; mode++) {
BitStream tempStream2(tempBuf2, 128, 0);
BC7CompressionMode compressorTry(mode, opaque);
double error = compressorTry.Compress(tempStream2, 0, &blockCluster);
if(error < best) {
best = error;
if(best == 0.0f) {
memcpy(outBuf, tempBuf2, 16);
return;
}
else {
memcpy(tempBuf1, tempBuf2, 16);
}
}
}
}
double error = CompressTwoClusters(bestShapeIdx[0], bestClusters[0], tempBuf2, opaque);
if(error < best) {
best = error;
if(error == 0.0f) {
memcpy(outBuf, tempBuf2, 16);
return;
}
else {
memcpy(tempBuf1, tempBuf2, 16);
}
}
if(opaque) {
if(CompressThreeClusters(bestShapeIdx[1], bestClusters[1], tempBuf2, opaque) < best) {
memcpy(outBuf, tempBuf2, 16);
return;
}
}
memcpy(outBuf, tempBuf1, 16);
}
static double EstimateTwoClusterErrorStats(RGBACluster &c, double (&estimates)[2]) {
RGBAVector Min, Max, v;
c.GetBoundingBox(Min, Max);
v = Max - Min;
if(v * v == 0) {
estimates[0] = estimates[1] = 0.0;
return 0.0;
}
const float *w = BC7C::GetErrorMetric();
const double err1 = c.QuantizedError(Min, Max, 8, 0xFFFCFCFC, RGBAVector(w[0], w[1], w[2], w[3]));
if(err1 >= 0.0)
estimates[0] = err1;
else
estimates[0] = min(estimates[0], err1);
const double err3 = c.QuantizedError(Min, Max, 8, 0xFFFEFEFE, RGBAVector(w[0], w[1], w[2], w[3]));
if(err3 >= 0.0)
estimates[1] = err3;
else
estimates[1] = min(estimates[1], err3);
double error = 0.0001;
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
double eigOne = c.GetPrincipalEigenvalue();
double eigTwo = c.GetSecondEigenvalue();
if(eigOne != 0.0) {
error += eigTwo / eigOne;
}
else {
error += 1.0;
}
#else
error += min(err1, err3);
#endif
return error;
}
static double EstimateThreeClusterErrorStats(RGBACluster &c, double (&estimates)[2]) {
RGBAVector Min, Max, v;
c.GetBoundingBox(Min, Max);
v = Max - Min;
if(v * v == 0) {
estimates[0] = estimates[1] = 0.0;
return 0.0;
}
const float *w = BC7C::GetErrorMetric();
const double err0 = 0.0001 + c.QuantizedError(Min, Max, 4, 0xFFF0F0F0, RGBAVector(w[0], w[1], w[2], w[3]));
if(err0 >= 0.0)
estimates[0] = err0;
else
estimates[0] = min(estimates[0], err0);
const double err2 = 0.0001 + c.QuantizedError(Min, Max, 4, 0xFFF8F8F8, RGBAVector(w[0], w[1], w[2], w[3]));
if(err2 >= 0.0)
estimates[1] = err2;
else
estimates[1] = min(estimates[1], err2);
double error = 0.0001;
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
double eigOne = c.GetPrincipalEigenvalue();
double eigTwo = c.GetSecondEigenvalue();
// printf("EigOne: %08.3f\tEigTwo: %08.3f\n", eigOne, eigTwo);
if(eigOne != 0.0) {
error += eigTwo / eigOne;
}
else {
error += 1.0;
}
#else
error += min(err0, err2);
#endif
return error;
}
static void UpdateErrorEstimate(double *estimates, uint32 mode, double est) {
assert(estimates);
assert(mode >= 0);
assert(mode < BC7CompressionMode::kNumModes);
if(estimates[mode] == -1.0 || est < estimates[mode]) {
estimates[mode] = est;
}
}
// Compress a single block but collect statistics as well...
static void CompressBC7Block(const uint32 *block, uint8 *outBuf, BlockStatManager &statManager) {
class RAIIStatSaver {
private:
uint32 m_BlockIdx;
BlockStatManager &m_BSM;
int *m_ModePtr;
double *m_Estimates;
double *m_Errors;
public:
RAIIStatSaver(uint32 blockIdx, BlockStatManager &m) : m_BlockIdx(blockIdx), m_BSM(m)
, m_ModePtr(NULL), m_Estimates(NULL), m_Errors(NULL) { }
void SetMode(int *modePtr) { m_ModePtr = modePtr; }
void SetEstimates(double *estimates) { m_Estimates = estimates; }
void SetErrors(double *errors) { m_Errors = errors; }
~RAIIStatSaver() {
assert(m_ModePtr);
assert(m_Estimates);
assert(m_Errors);
BlockStat s (kBlockStatString[eBlockStat_Mode], *m_ModePtr);
m_BSM.AddStat(m_BlockIdx, s);
for(uint32 i = 0; i < BC7CompressionMode::kNumModes; i++) {
s = BlockStat(kBlockStatString[eBlockStat_ModeZeroEstimate + i], m_Estimates[i]);
m_BSM.AddStat(m_BlockIdx, s);
s = BlockStat(kBlockStatString[eBlockStat_ModeZeroError + i], m_Errors[i]);
m_BSM.AddStat(m_BlockIdx, s);
}
}
};
int bestMode = 0;
double modeEstimate[BC7CompressionMode::kNumModes];
double modeError[BC7CompressionMode::kNumModes];
// reset global variables...
bestMode = 0;
for(uint32 i = 0; i < BC7CompressionMode::kNumModes; i++){
modeError[i] = modeEstimate[i] = -1.0;
}
uint32 blockIdx = statManager.BeginBlock();
for(int i = 0; i < kNumBlockStats; i++) {
statManager.AddStat(blockIdx, BlockStat(kBlockStatString[i], 0));
}
RAIIStatSaver __statsaver__(blockIdx, statManager);
__statsaver__.SetMode(&bestMode);
__statsaver__.SetEstimates(modeEstimate);
__statsaver__.SetErrors(modeError);
// All a single color?
if(AllOneColor(block)) {
BitStream bStrm(outBuf, 128, 0);
CompressOptimalColorBC7(*block, bStrm);
bestMode = 5;
BlockStat s = BlockStat(kBlockStatString[eBlockStat_Path], 0);
statManager.AddStat(blockIdx, s);
return;
}
RGBACluster blockCluster;
bool opaque = true;
bool transparent = true;
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
RGBAVector p = RGBAVector(i, block[i]);
blockCluster.AddPoint(p);
if(fabs(p.a - 255.0f) > 1e-10)
opaque = false;
if(p.a > 0.0f)
transparent = false;
}
// The whole block is transparent?
if(transparent) {
BitStream bStrm(outBuf, 128, 0);
WriteTransparentBlock(bStrm);
bestMode = 6;
BlockStat s = BlockStat(kBlockStatString[eBlockStat_Path], 1);
statManager.AddStat(blockIdx, s);
return;
}
// First, estimate the error it would take to compress a single line with
// mode 6...
{
RGBAVector Min, Max, v;
blockCluster.GetBoundingBox(Min, Max);
v = Max - Min;
if(v * v == 0) {
modeEstimate[6] = 0.0;
}
else {
const float *w = GetErrorMetric();
const double err = 0.0001 + blockCluster.QuantizedError(Min, Max, 4, 0xFEFEFEFE, RGBAVector(w[0], w[1], w[2], w[3]));
UpdateErrorEstimate(modeEstimate, 6, err);
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
double eigOne = blockCluster.GetPrincipalEigenvalue();
double eigTwo = blockCluster.GetSecondEigenvalue();
double error;
if(eigOne != 0.0) {
error = eigTwo / eigOne;
}
else {
error = 1.0;
}
BlockStat s (kBlockStatString[eBlockStat_SingleShapeEstimate], error);
statManager.AddStat(blockIdx, s);
#endif
}
}
// First we must figure out which shape to use. To do this, simply
// see which shape has the smallest sum of minimum bounding spheres.
double bestError[2] = { DBL_MAX, DBL_MAX };
int bestShapeIdx[2] = { -1, -1 };
RGBACluster bestClusters[2][3];
for(unsigned int i = 0; i < kNumShapes2; i++)
{
RGBACluster clusters[2];
PopulateTwoClustersForShape(blockCluster, i, clusters);
double err = 0.0;
double errEstimate[2] = { -1.0, -1.0 };
for(int ci = 0; ci < 2; ci++) {
double shapeEstimate[2] = { -1.0, -1.0 };
err += EstimateTwoClusterErrorStats(clusters[ci], shapeEstimate);
for(int ei = 0; ei < 2; ei++) {
if(shapeEstimate[ei] >= 0.0) {
if(errEstimate[ei] == -1.0) {
errEstimate[ei] = shapeEstimate[ei];
}
else {
errEstimate[ei] += shapeEstimate[ei];
}
}
}
}
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
err /= 2.0;
#endif
if(errEstimate[0] != -1.0) {
UpdateErrorEstimate(modeEstimate, 1, errEstimate[0]);
}
if(errEstimate[1] != -1.0) {
UpdateErrorEstimate(modeEstimate, 3, errEstimate[1]);
}
if(err < bestError[0]) {
BlockStat s = BlockStat(kBlockStatString[eBlockStat_TwoShapeEstimate], err);
statManager.AddStat(blockIdx, s);
}
// If it's small, we'll take it!
if(err < 1e-9) {
int modeChosen;
CompressTwoClusters(i, clusters, outBuf, opaque, modeError, &modeChosen);
bestMode = modeChosen;
BlockStat s = BlockStat(kBlockStatString[eBlockStat_Path], 2);
statManager.AddStat(blockIdx, s);
return;
}
if(err < bestError[0]) {
bestError[0] = err;
bestShapeIdx[0] = i;
bestClusters[0][0] = clusters[0];
bestClusters[0][1] = clusters[1];
}
}
// There are not 3 subset blocks that support alpha, so only check these
// if the entire block is opaque.
if(opaque) {
for(unsigned int i = 0; i < kNumShapes3; i++) {
RGBACluster clusters[3];
PopulateThreeClustersForShape(blockCluster, i, clusters);
double err = 0.0;
double errEstimate[2] = { -1.0, -1.0 };
for(int ci = 0; ci < 3; ci++) {
double shapeEstimate[2] = { -1.0, -1.0 };
err += EstimateThreeClusterErrorStats(clusters[ci], shapeEstimate);
for(int ei = 0; ei < 2; ei++) {
if(shapeEstimate[ei] >= 0.0) {
if(errEstimate[ei] == -1.0) {
errEstimate[ei] = shapeEstimate[ei];
}
else {
errEstimate[ei] += shapeEstimate[ei];
}
}
}
}
#ifdef USE_PCA_FOR_SHAPE_ESTIMATION
err /= 3.0;
#endif
if(errEstimate[0] != -1.0) {
UpdateErrorEstimate(modeEstimate, 0, errEstimate[0]);
}
if(errEstimate[1] != -1.0) {
UpdateErrorEstimate(modeEstimate, 2, errEstimate[1]);
}
if(err < bestError[1]) {
BlockStat s = BlockStat(kBlockStatString[eBlockStat_ThreeShapeEstimate], err);
statManager.AddStat(blockIdx, s);
}
// If it's small, we'll take it!
if(err < 1e-9) {
int modeChosen;
CompressThreeClusters(i, clusters, outBuf, opaque, modeError, &modeChosen);
bestMode = modeChosen;
BlockStat s = BlockStat(kBlockStatString[eBlockStat_Path], 2);
statManager.AddStat(blockIdx, s);
return;
}
if(err < bestError[1]) {
bestError[1] = err;
bestShapeIdx[1] = i;
bestClusters[1][0] = clusters[0];
bestClusters[1][1] = clusters[1];
bestClusters[1][2] = clusters[2];
}
}
}
BlockStat s = BlockStat(kBlockStatString[eBlockStat_Path], 3);
statManager.AddStat(blockIdx, s);
uint8 tempBuf1[16], tempBuf2[16];
BitStream tempStream1 (tempBuf1, 128, 0);
BC7CompressionMode compressor(6, opaque);
double best = compressor.Compress(tempStream1, 0, &blockCluster);
modeError[6] = best;
bestMode = 6;
if(best == 0.0f) {
memcpy(outBuf, tempBuf1, 16);
return;
}
// Check modes 4 and 5 if the block isn't opaque...
if(!opaque) {
for(int mode = 4; mode <= 5; mode++) {
BitStream tempStream2(tempBuf2, 128, 0);
BC7CompressionMode compressorTry(mode, opaque);
double error = compressorTry.Compress(tempStream2, 0, &blockCluster);
if(error < best) {
bestMode = mode;
best = error;
if(best == 0.0f) {
memcpy(outBuf, tempBuf2, 16);
return;
}
else {
memcpy(tempBuf1, tempBuf2, 16);
}
}
}
}
int modeChosen;
double error = CompressTwoClusters(bestShapeIdx[0], bestClusters[0], tempBuf2, opaque, modeError, &modeChosen);
if(error < best) {
bestMode = modeChosen;
best = error;
if(error == 0.0f) {
memcpy(outBuf, tempBuf2, 16);
return;
}
else {
memcpy(tempBuf1, tempBuf2, 16);
}
}
if(opaque) {
if(CompressThreeClusters(bestShapeIdx[1], bestClusters[1], tempBuf2, opaque, modeError, &modeChosen) < best) {
bestMode = modeChosen;
memcpy(outBuf, tempBuf2, 16);
return;
}
}
memcpy(outBuf, tempBuf1, 16);
}
static void DecompressBC7Block(const uint8 block[16], uint32 outBuf[16]) {
BitStreamReadOnly strm(block);
uint32 mode = 0;
while(!strm.ReadBit()) {
mode++;
}
const BC7CompressionMode::Attributes *attrs = BC7CompressionMode::GetAttributesForMode(mode);
const uint32 nSubsets = attrs->numSubsets;
uint32 idxMode = 0;
uint32 rotMode = 0;
uint32 shapeIdx = 0;
if ( nSubsets > 1 ) {
shapeIdx = strm.ReadBits(mode == 0? 4 : 6);
}
else if( attrs->hasRotation ) {
rotMode = strm.ReadBits(2);
if( attrs->hasIdxMode )
idxMode = strm.ReadBit();
}
assert(idxMode < 2);
assert(rotMode < 4);
assert(shapeIdx < uint32((mode == 0)? 16 : 64));
uint32 cp = attrs->colorChannelPrecision;
const uint32 shift = 8 - cp;
uint8 eps[3][2][4];
for(uint32 ch = 0; ch < 3; ch++)
for(uint32 i = 0; i < nSubsets; i++)
for(uint32 ep = 0; ep < 2; ep++)
eps[i][ep][ch] = strm.ReadBits(cp) << shift;
uint32 ap = attrs->alphaChannelPrecision;
const uint32 ash = 8 - ap;
if(ap == 0) {
for(uint32 i = 0; i < nSubsets; i++)
for(uint32 ep = 0; ep < 2; ep++)
eps[i][ep][3] = 0xFF;
}
else {
for(uint32 i = 0; i < nSubsets; i++)
for(uint32 ep = 0; ep < 2; ep++)
eps[i][ep][3] = strm.ReadBits(ap) << ash;
}
// Handle pbits
switch(attrs->pbitType) {
case BC7CompressionMode::ePBitType_None:
// Do nothing.
break;
case BC7CompressionMode::ePBitType_Shared:
cp += 1;
ap += 1;
for(uint32 i = 0; i < nSubsets; i++) {
uint32 pbit = strm.ReadBit();
for(uint32 j = 0; j < 2; j++)
for(uint32 ch = 0; ch < kNumColorChannels; ch++) {
const uint32 prec = ch == 3? ap : cp;
eps[i][j][ch] |= pbit << (8-prec);
}
}
break;
case BC7CompressionMode::ePBitType_NotShared:
cp += 1;
ap += 1;
for(uint32 i = 0; i < nSubsets; i++)
for(uint32 j = 0; j < 2; j++) {
uint32 pbit = strm.ReadBit();
for(uint32 ch = 0; ch < kNumColorChannels; ch++) {
const uint32 prec = ch == 3? ap : cp;
eps[i][j][ch] |= pbit << (8-prec);
}
}
break;
}
// Quantize endpoints...
for(uint32 i = 0; i < nSubsets; i++)
for(uint32 j = 0; j < 2; j++)
for(uint32 ch = 0; ch < kNumColorChannels; ch++) {
const uint32 prec = ch == 3? ap : cp;
eps[i][j][ch] |= eps[i][j][ch] >> prec;
}
// Figure out indices...
uint32 alphaIndices[kMaxNumDataPoints];
uint32 colorIndices[kMaxNumDataPoints];
int nBitsPerAlpha = attrs->numBitsPerAlpha;
int nBitsPerColor = attrs->numBitsPerIndex;
uint32 idxPrec = attrs->numBitsPerIndex;
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
uint32 subset = GetSubsetForIndex(i, shapeIdx, nSubsets);
int idx = 0;
if(GetAnchorIndexForSubset(subset, shapeIdx, nSubsets) == i) {
idx = strm.ReadBits(idxPrec - 1);
}
else {
idx = strm.ReadBits(idxPrec);
}
colorIndices[i] = idx;
}
idxPrec = attrs->numBitsPerAlpha;
if(idxPrec == 0) {
memcpy(alphaIndices, colorIndices, sizeof(alphaIndices));
}
else {
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
uint32 subset = GetSubsetForIndex(i, shapeIdx, nSubsets);
int idx = 0;
if(GetAnchorIndexForSubset(subset, shapeIdx, nSubsets) == i) {
idx = strm.ReadBits(idxPrec - 1);
}
else {
idx = strm.ReadBits(idxPrec);
}
alphaIndices[i] = idx;
}
if(idxMode) {
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
swap(alphaIndices[i], colorIndices[i]);
}
swap(nBitsPerAlpha, nBitsPerColor);
}
}
assert(strm.GetBitsRead() == 128);
// Get final colors by interpolating...
for(uint32 i = 0; i < kMaxNumDataPoints; i++) {
const uint32 subset = GetSubsetForIndex(i, shapeIdx, nSubsets);
uint32 &pixel = outBuf[i];
pixel = 0;
for(int ch = 0; ch < 4; ch++) {
if(ch == 3 && nBitsPerAlpha > 0) {
uint32 i0 = kBC7InterpolationValues[nBitsPerAlpha - 1][alphaIndices[i]][0];
uint32 i1 = kBC7InterpolationValues[nBitsPerAlpha - 1][alphaIndices[i]][1];
const uint8 ip = (((uint32(eps[subset][0][3]) * i0) + (uint32(eps[subset][1][3]) * i1) + 32) >> 6) & 0xFF;
pixel |= ip << 24;
}
else {
uint32 i0 = kBC7InterpolationValues[nBitsPerColor - 1][colorIndices[i]][0];
uint32 i1 = kBC7InterpolationValues[nBitsPerColor - 1][colorIndices[i]][1];
const uint8 ip = (((uint32(eps[subset][0][ch]) * i0) + (uint32(eps[subset][1][ch]) * i1) + 32) >> 6) & 0xFF;
pixel |= ip << (8*ch);
}
}
// Swap colors if necessary...
uint8 *pb = (uint8 *)&pixel;
switch(rotMode) {
default:
case 0:
// Do nothing
break;
case 1:
swap(pb[0], pb[3]);
break;
case 2:
swap(pb[1], pb[3]);
break;
case 3:
swap(pb[2], pb[3]);
break;
}
}
}
// Convert the image from a BC7 buffer to a RGBA8 buffer
void DecompressImageBC7(const uint8 *inBuf, uint8* outBuf, unsigned int width, unsigned int height) {
unsigned int blockIdx = 0;
// for(unsigned int j = 0; j < height; j += 4, outBuf += width * 3 * 4)
for(unsigned int j = 0; j < height; j += 4)
{
for(unsigned int i = 0; i < width; i += 4)
{
uint32 pixels[16];
DecompressBC7Block(inBuf + (16*(blockIdx++)), pixels);
memcpy(outBuf, pixels, 16 * sizeof(uint32));
//memcpy(outBuf + (width * 4), pixels + 4, 4 * sizeof(uint32));
//memcpy(outBuf + 2*(width * 4), pixels + 8, 4 * sizeof(uint32));
//memcpy(outBuf + 3*(width * 4), pixels + 12, 4 * sizeof(uint32));
//outBuf += 16;
outBuf += 64;
}
}
}
}
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