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pandemonium_engine_minimal/thirdparty/etc2comp/EtcBlock4x4Encoding_ETC1.cpp

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Initial Commit.
2023-12-14 21:54:22 +01:00
/*
* Copyright 2015 The Etc2Comp Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
EtcBlock4x4Encoding_ETC1.cpp
Block4x4Encoding_ETC1 is the encoder to use when targetting file format ETC1. This encoder is also
used for the ETC1 subset of file format RGB8, RGBA8 and RGB8A1
*/
#include "EtcConfig.h"
#include "EtcBlock4x4Encoding_ETC1.h"
#include "EtcBlock4x4.h"
#include "EtcBlock4x4EncodingBits.h"
#include "EtcDifferentialTrys.h"
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <float.h>
#include <limits>
namespace Etc
{
// pixel processing order if the flip bit = 0 (horizontal split)
const unsigned int Block4x4Encoding_ETC1::s_auiPixelOrderFlip0[PIXELS] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
// pixel processing order if the flip bit = 1 (vertical split)
const unsigned int Block4x4Encoding_ETC1::s_auiPixelOrderFlip1[PIXELS] = { 0, 1, 4, 5, 8, 9, 12, 13, 2, 3, 6, 7, 10, 11, 14, 15 };
// pixel processing order for horizontal scan (ETC normally does a vertical scan)
const unsigned int Block4x4Encoding_ETC1::s_auiPixelOrderHScan[PIXELS] = { 0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15 };
// pixel indices for different block halves
const unsigned int Block4x4Encoding_ETC1::s_auiLeftPixelMapping[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };
const unsigned int Block4x4Encoding_ETC1::s_auiRightPixelMapping[8] = { 8, 9, 10, 11, 12, 13, 14, 15 };
const unsigned int Block4x4Encoding_ETC1::s_auiTopPixelMapping[8] = { 0, 1, 4, 5, 8, 9, 12, 13 };
const unsigned int Block4x4Encoding_ETC1::s_auiBottomPixelMapping[8] = { 2, 3, 6, 7, 10, 11, 14, 15 };
// CW ranges that the ETC1 decoders use
// CW is basically a contrast for the different selector bits, since these values are offsets to the base color
// the first axis in the array is indexed by the CW in the encoding bits
// the second axis in the array is indexed by the selector bits
float Block4x4Encoding_ETC1::s_aafCwTable[CW_RANGES][SELECTORS] =
{
{ 2.0f / 255.0f, 8.0f / 255.0f, -2.0f / 255.0f, -8.0f / 255.0f },
{ 5.0f / 255.0f, 17.0f / 255.0f, -5.0f / 255.0f, -17.0f / 255.0f },
{ 9.0f / 255.0f, 29.0f / 255.0f, -9.0f / 255.0f, -29.0f / 255.0f },
{ 13.0f / 255.0f, 42.0f / 255.0f, -13.0f / 255.0f, -42.0f / 255.0f },
{ 18.0f / 255.0f, 60.0f / 255.0f, -18.0f / 255.0f, -60.0f / 255.0f },
{ 24.0f / 255.0f, 80.0f / 255.0f, -24.0f / 255.0f, -80.0f / 255.0f },
{ 33.0f / 255.0f, 106.0f / 255.0f, -33.0f / 255.0f, -106.0f / 255.0f },
{ 47.0f / 255.0f, 183.0f / 255.0f, -47.0f / 255.0f, -183.0f / 255.0f }
};
// ----------------------------------------------------------------------------------------------------
//
Block4x4Encoding_ETC1::Block4x4Encoding_ETC1(void)
{
m_mode = MODE_ETC1;
m_boolDiff = false;
m_boolFlip = false;
m_frgbaColor1 = ColorFloatRGBA();
m_frgbaColor2 = ColorFloatRGBA();
m_uiCW1 = 0;
m_uiCW2 = 0;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
m_auiSelectors[uiPixel] = 0;
m_afDecodedAlphas[uiPixel] = 1.0f;
}
m_boolMostLikelyFlip = false;
m_fError = -1.0f;
m_fError1 = -1.0f;
m_fError2 = -1.0f;
m_boolSeverelyBentDifferentialColors = false;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
m_afDecodedAlphas[uiPixel] = 1.0f;
}
}
Block4x4Encoding_ETC1::~Block4x4Encoding_ETC1(void) {}
// ----------------------------------------------------------------------------------------------------
// initialization prior to encoding
// a_pblockParent points to the block associated with this encoding
// a_errormetric is used to choose the best encoding
// a_pafrgbaSource points to a 4x4 block subset of the source image
// a_paucEncodingBits points to the final encoding bits
//
void Block4x4Encoding_ETC1::InitFromSource(Block4x4 *a_pblockParent,
ColorFloatRGBA *a_pafrgbaSource,
unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric)
{
Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric);
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
m_afDecodedAlphas[uiPixel] = 1.0f;
}
m_fError = -1.0f;
m_pencodingbitsRGB8 = (Block4x4EncodingBits_RGB8 *)(a_paucEncodingBits);
}
// ----------------------------------------------------------------------------------------------------
// initialization from the encoding bits of a previous encoding
// a_pblockParent points to the block associated with this encoding
// a_errormetric is used to choose the best encoding
// a_pafrgbaSource points to a 4x4 block subset of the source image
// a_paucEncodingBits points to the final encoding bits of a previous encoding
//
void Block4x4Encoding_ETC1::InitFromEncodingBits(Block4x4 *a_pblockParent,
unsigned char *a_paucEncodingBits,
ColorFloatRGBA *a_pafrgbaSource,
ErrorMetric a_errormetric)
{
Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric);
m_fError = -1.0f;
m_pencodingbitsRGB8 = (Block4x4EncodingBits_RGB8 *)a_paucEncodingBits;
m_mode = MODE_ETC1;
m_boolDiff = m_pencodingbitsRGB8->individual.diff;
m_boolFlip = m_pencodingbitsRGB8->individual.flip;
if (m_boolDiff)
{
int iR2 = (int)(m_pencodingbitsRGB8->differential.red1 + m_pencodingbitsRGB8->differential.dred2);
if (iR2 < 0)
{
iR2 = 0;
}
else if (iR2 > 31)
{
iR2 = 31;
}
int iG2 = (int)(m_pencodingbitsRGB8->differential.green1 + m_pencodingbitsRGB8->differential.dgreen2);
if (iG2 < 0)
{
iG2 = 0;
}
else if (iG2 > 31)
{
iG2 = 31;
}
int iB2 = (int)(m_pencodingbitsRGB8->differential.blue1 + m_pencodingbitsRGB8->differential.dblue2);
if (iB2 < 0)
{
iB2 = 0;
}
else if (iB2 > 31)
{
iB2 = 31;
}
m_frgbaColor1 = ColorFloatRGBA::ConvertFromRGB5(m_pencodingbitsRGB8->differential.red1, m_pencodingbitsRGB8->differential.green1, m_pencodingbitsRGB8->differential.blue1);
m_frgbaColor2 = ColorFloatRGBA::ConvertFromRGB5((unsigned char)iR2, (unsigned char)iG2, (unsigned char)iB2);
}
else
{
m_frgbaColor1 = ColorFloatRGBA::ConvertFromRGB4(m_pencodingbitsRGB8->individual.red1, m_pencodingbitsRGB8->individual.green1, m_pencodingbitsRGB8->individual.blue1);
m_frgbaColor2 = ColorFloatRGBA::ConvertFromRGB4(m_pencodingbitsRGB8->individual.red2, m_pencodingbitsRGB8->individual.green2, m_pencodingbitsRGB8->individual.blue2);
}
m_uiCW1 = m_pencodingbitsRGB8->individual.cw1;
m_uiCW2 = m_pencodingbitsRGB8->individual.cw2;
InitFromEncodingBits_Selectors();
Decode();
CalcBlockError();
}
// ----------------------------------------------------------------------------------------------------
// init the selectors from a prior encoding
//
void Block4x4Encoding_ETC1::InitFromEncodingBits_Selectors(void)
{
unsigned char *paucSelectors = (unsigned char *)&m_pencodingbitsRGB8->individual.selectors;
for (unsigned int iPixel = 0; iPixel < PIXELS; iPixel++)
{
unsigned int uiByteMSB = (unsigned int)(1 - (iPixel / 8));
unsigned int uiByteLSB = (unsigned int)(3 - (iPixel / 8));
unsigned int uiShift = (unsigned int)(iPixel & 7);
unsigned int uiSelectorMSB = (unsigned int)((paucSelectors[uiByteMSB] >> uiShift) & 1);
unsigned int uiSelectorLSB = (unsigned int)((paucSelectors[uiByteLSB] >> uiShift) & 1);
m_auiSelectors[iPixel] = (uiSelectorMSB << 1) + uiSelectorLSB;
}
}
// ----------------------------------------------------------------------------------------------------
// perform a single encoding iteration
// replace the encoding if a better encoding was found
// subsequent iterations generally take longer for each iteration
// set m_boolDone if encoding is perfect or encoding is finished based on a_fEffort
//
void Block4x4Encoding_ETC1::PerformIteration(float a_fEffort)
{
assert(!m_boolDone);
switch (m_uiEncodingIterations)
{
case 0:
PerformFirstIteration();
break;
case 1:
TryDifferential(m_boolMostLikelyFlip, 1, 0, 0);
break;
case 2:
TryIndividual(m_boolMostLikelyFlip, 1);
if (a_fEffort <= 49.5f)
{
m_boolDone = true;
}
break;
case 3:
TryDifferential(!m_boolMostLikelyFlip, 1, 0, 0);
if (a_fEffort <= 59.5f)
{
m_boolDone = true;
}
break;
case 4:
TryIndividual(!m_boolMostLikelyFlip, 1);
if (a_fEffort <= 69.5f)
{
m_boolDone = true;
}
break;
case 5:
TryDegenerates1();
if (a_fEffort <= 79.5f)
{
m_boolDone = true;
}
break;
case 6:
TryDegenerates2();
if (a_fEffort <= 89.5f)
{
m_boolDone = true;
}
break;
case 7:
TryDegenerates3();
if (a_fEffort <= 99.5f)
{
m_boolDone = true;
}
break;
case 8:
TryDegenerates4();
m_boolDone = true;
break;
default:
assert(0);
break;
}
m_uiEncodingIterations++;
SetDoneIfPerfect();
}
// ----------------------------------------------------------------------------------------------------
// find best initial encoding to ensure block has a valid encoding
//
void Block4x4Encoding_ETC1::PerformFirstIteration(void)
{
CalculateMostLikelyFlip();
m_fError = FLT_MAX;
TryDifferential(m_boolMostLikelyFlip, 0, 0, 0);
SetDoneIfPerfect();
if (m_boolDone)
{
return;
}
TryIndividual(m_boolMostLikelyFlip, 0);
SetDoneIfPerfect();
if (m_boolDone)
{
return;
}
TryDifferential(!m_boolMostLikelyFlip, 0, 0, 0);
SetDoneIfPerfect();
if (m_boolDone)
{
return;
}
TryIndividual(!m_boolMostLikelyFlip, 0);
}
// ----------------------------------------------------------------------------------------------------
// algorithm:
// create a source average color for the Left, Right, Top and Bottom halves using the 8 pixels in each half
// note: the "gray line" is the line of equal delta RGB that goes thru the average color
// for each half:
// see how close each of the 8 pixels are to the "gray line" that goes thru the source average color
// create an error value that is the sum of the distances from the gray line
// h_error is the sum of Left and Right errors
// v_error is the sum of Top and Bottom errors
//
void Block4x4Encoding_ETC1::CalculateMostLikelyFlip(void)
{
static const bool DEBUG_PRINT = false;
CalculateSourceAverages();
float fLeftGrayErrorSum = 0.0f;
float fRightGrayErrorSum = 0.0f;
float fTopGrayErrorSum = 0.0f;
float fBottomGrayErrorSum = 0.0f;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
ColorFloatRGBA *pfrgbaLeft = &m_pafrgbaSource[uiPixel];
ColorFloatRGBA *pfrgbaRight = &m_pafrgbaSource[uiPixel + 8];
ColorFloatRGBA *pfrgbaTop = &m_pafrgbaSource[s_auiTopPixelMapping[uiPixel]];
ColorFloatRGBA *pfrgbaBottom = &m_pafrgbaSource[s_auiBottomPixelMapping[uiPixel]];
float fLeftGrayError = CalcGrayDistance2(*pfrgbaLeft, m_frgbaSourceAverageLeft);
float fRightGrayError = CalcGrayDistance2(*pfrgbaRight, m_frgbaSourceAverageRight);
float fTopGrayError = CalcGrayDistance2(*pfrgbaTop, m_frgbaSourceAverageTop);
float fBottomGrayError = CalcGrayDistance2(*pfrgbaBottom, m_frgbaSourceAverageBottom);
fLeftGrayErrorSum += fLeftGrayError;
fRightGrayErrorSum += fRightGrayError;
fTopGrayErrorSum += fTopGrayError;
fBottomGrayErrorSum += fBottomGrayError;
}
if (DEBUG_PRINT)
{
printf("\n%.2f %.2f\n", fLeftGrayErrorSum + fRightGrayErrorSum, fTopGrayErrorSum + fBottomGrayErrorSum);
}
m_boolMostLikelyFlip = (fTopGrayErrorSum + fBottomGrayErrorSum) < (fLeftGrayErrorSum + fRightGrayErrorSum);
}
// ----------------------------------------------------------------------------------------------------
// calculate source pixel averages for each 2x2 quadrant in a 4x4 block
// these are used to determine the averages for each of the 4 different halves (left, right, top, bottom)
// ignore pixels that have alpha == NAN (these are border pixels outside of the source image)
// weight the averages based on a pixel's alpha
//
void Block4x4Encoding_ETC1::CalculateSourceAverages(void)
{
static const bool DEBUG_PRINT = false;
bool boolRGBX = m_pblockParent->GetImageSource()->GetErrorMetric() == ErrorMetric::RGBX;
if (m_pblockParent->GetSourceAlphaMix() == Block4x4::SourceAlphaMix::OPAQUE || boolRGBX)
{
ColorFloatRGBA frgbaSumUL = m_pafrgbaSource[0] + m_pafrgbaSource[1] + m_pafrgbaSource[4] + m_pafrgbaSource[5];
ColorFloatRGBA frgbaSumLL = m_pafrgbaSource[2] + m_pafrgbaSource[3] + m_pafrgbaSource[6] + m_pafrgbaSource[7];
ColorFloatRGBA frgbaSumUR = m_pafrgbaSource[8] + m_pafrgbaSource[9] + m_pafrgbaSource[12] + m_pafrgbaSource[13];
ColorFloatRGBA frgbaSumLR = m_pafrgbaSource[10] + m_pafrgbaSource[11] + m_pafrgbaSource[14] + m_pafrgbaSource[15];
m_frgbaSourceAverageLeft = (frgbaSumUL + frgbaSumLL) * 0.125f;
m_frgbaSourceAverageRight = (frgbaSumUR + frgbaSumLR) * 0.125f;
m_frgbaSourceAverageTop = (frgbaSumUL + frgbaSumUR) * 0.125f;
m_frgbaSourceAverageBottom = (frgbaSumLL + frgbaSumLR) * 0.125f;
}
else
{
float afSourceAlpha[PIXELS];
// treat alpha NAN as 0.0f
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
afSourceAlpha[uiPixel] = isnan(m_pafrgbaSource[uiPixel].fA) ?
0.0f :
m_pafrgbaSource[uiPixel].fA;
}
ColorFloatRGBA afrgbaAlphaWeightedSource[PIXELS];
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
afrgbaAlphaWeightedSource[uiPixel] = m_pafrgbaSource[uiPixel] * afSourceAlpha[uiPixel];
}
ColorFloatRGBA frgbaSumUL = afrgbaAlphaWeightedSource[0] +
afrgbaAlphaWeightedSource[1] +
afrgbaAlphaWeightedSource[4] +
afrgbaAlphaWeightedSource[5];
ColorFloatRGBA frgbaSumLL = afrgbaAlphaWeightedSource[2] +
afrgbaAlphaWeightedSource[3] +
afrgbaAlphaWeightedSource[6] +
afrgbaAlphaWeightedSource[7];
ColorFloatRGBA frgbaSumUR = afrgbaAlphaWeightedSource[8] +
afrgbaAlphaWeightedSource[9] +
afrgbaAlphaWeightedSource[12] +
afrgbaAlphaWeightedSource[13];
ColorFloatRGBA frgbaSumLR = afrgbaAlphaWeightedSource[10] +
afrgbaAlphaWeightedSource[11] +
afrgbaAlphaWeightedSource[14] +
afrgbaAlphaWeightedSource[15];
float fWeightSumUL = afSourceAlpha[0] +
afSourceAlpha[1] +
afSourceAlpha[4] +
afSourceAlpha[5];
float fWeightSumLL = afSourceAlpha[2] +
afSourceAlpha[3] +
afSourceAlpha[6] +
afSourceAlpha[7];
float fWeightSumUR = afSourceAlpha[8] +
afSourceAlpha[9] +
afSourceAlpha[12] +
afSourceAlpha[13];
float fWeightSumLR = afSourceAlpha[10] +
afSourceAlpha[11] +
afSourceAlpha[14] +
afSourceAlpha[15];
ColorFloatRGBA frgbaSumLeft = frgbaSumUL + frgbaSumLL;
ColorFloatRGBA frgbaSumRight = frgbaSumUR + frgbaSumLR;
ColorFloatRGBA frgbaSumTop = frgbaSumUL + frgbaSumUR;
ColorFloatRGBA frgbaSumBottom = frgbaSumLL + frgbaSumLR;
float fWeightSumLeft = fWeightSumUL + fWeightSumLL;
float fWeightSumRight = fWeightSumUR + fWeightSumLR;
float fWeightSumTop = fWeightSumUL + fWeightSumUR;
float fWeightSumBottom = fWeightSumLL + fWeightSumLR;
// check to see if there is at least 1 pixel with non-zero alpha
// completely transparent block should not make it to this code
assert((fWeightSumLeft + fWeightSumRight) > 0.0f);
assert((fWeightSumTop + fWeightSumBottom) > 0.0f);
if (fWeightSumLeft > 0.0f)
{
m_frgbaSourceAverageLeft = frgbaSumLeft * (1.0f/fWeightSumLeft);
}
if (fWeightSumRight > 0.0f)
{
m_frgbaSourceAverageRight = frgbaSumRight * (1.0f/fWeightSumRight);
}
if (fWeightSumTop > 0.0f)
{
m_frgbaSourceAverageTop = frgbaSumTop * (1.0f/fWeightSumTop);
}
if (fWeightSumBottom > 0.0f)
{
m_frgbaSourceAverageBottom = frgbaSumBottom * (1.0f/fWeightSumBottom);
}
if (fWeightSumLeft == 0.0f)
{
assert(fWeightSumRight > 0.0f);
m_frgbaSourceAverageLeft = m_frgbaSourceAverageRight;
}
if (fWeightSumRight == 0.0f)
{
assert(fWeightSumLeft > 0.0f);
m_frgbaSourceAverageRight = m_frgbaSourceAverageLeft;
}
if (fWeightSumTop == 0.0f)
{
assert(fWeightSumBottom > 0.0f);
m_frgbaSourceAverageTop = m_frgbaSourceAverageBottom;
}
if (fWeightSumBottom == 0.0f)
{
assert(fWeightSumTop > 0.0f);
m_frgbaSourceAverageBottom = m_frgbaSourceAverageTop;
}
}
if (DEBUG_PRINT)
{
printf("\ntarget: [%.2f,%.2f,%.2f] [%.2f,%.2f,%.2f] [%.2f,%.2f,%.2f] [%.2f,%.2f,%.2f]\n",
m_frgbaSourceAverageLeft.fR, m_frgbaSourceAverageLeft.fG, m_frgbaSourceAverageLeft.fB,
m_frgbaSourceAverageRight.fR, m_frgbaSourceAverageRight.fG, m_frgbaSourceAverageRight.fB,
m_frgbaSourceAverageTop.fR, m_frgbaSourceAverageTop.fG, m_frgbaSourceAverageTop.fB,
m_frgbaSourceAverageBottom.fR, m_frgbaSourceAverageBottom.fG, m_frgbaSourceAverageBottom.fB);
}
}
// ----------------------------------------------------------------------------------------------------
// try an ETC1 differential mode encoding
// use a_boolFlip to set the encoding F bit
// use a_uiRadius to alter basecolor components in the range[-a_uiRadius:a_uiRadius]
// use a_iGrayOffset1 and a_iGrayOffset2 to offset the basecolor to search for degenerate encodings
// replace the encoding if the encoding error is less than previous encoding
//
void Block4x4Encoding_ETC1::TryDifferential(bool a_boolFlip, unsigned int a_uiRadius,
int a_iGrayOffset1, int a_iGrayOffset2)
{
ColorFloatRGBA frgbaColor1;
ColorFloatRGBA frgbaColor2;
const unsigned int *pauiPixelMapping1;
const unsigned int *pauiPixelMapping2;
if (a_boolFlip)
{
frgbaColor1 = m_frgbaSourceAverageTop;
frgbaColor2 = m_frgbaSourceAverageBottom;
pauiPixelMapping1 = s_auiTopPixelMapping;
pauiPixelMapping2 = s_auiBottomPixelMapping;
}
else
{
frgbaColor1 = m_frgbaSourceAverageLeft;
frgbaColor2 = m_frgbaSourceAverageRight;
pauiPixelMapping1 = s_auiLeftPixelMapping;
pauiPixelMapping2 = s_auiRightPixelMapping;
}
DifferentialTrys trys(frgbaColor1, frgbaColor2, pauiPixelMapping1, pauiPixelMapping2,
a_uiRadius, a_iGrayOffset1, a_iGrayOffset2);
Block4x4Encoding_ETC1 encodingTry = *this;
encodingTry.m_boolFlip = a_boolFlip;
encodingTry.TryDifferentialHalf(&trys.m_half1);
encodingTry.TryDifferentialHalf(&trys.m_half2);
// find best halves that are within differential range
DifferentialTrys::Try *ptryBest1 = nullptr;
DifferentialTrys::Try *ptryBest2 = nullptr;
encodingTry.m_fError = FLT_MAX;
// see if the best of each half are in differential range
int iDRed = trys.m_half2.m_ptryBest->m_iRed - trys.m_half1.m_ptryBest->m_iRed;
int iDGreen = trys.m_half2.m_ptryBest->m_iGreen - trys.m_half1.m_ptryBest->m_iGreen;
int iDBlue = trys.m_half2.m_ptryBest->m_iBlue - trys.m_half1.m_ptryBest->m_iBlue;
if (iDRed >= -4 && iDRed <= 3 && iDGreen >= -4 && iDGreen <= 3 && iDBlue >= -4 && iDBlue <= 3)
{
ptryBest1 = trys.m_half1.m_ptryBest;
ptryBest2 = trys.m_half2.m_ptryBest;
encodingTry.m_fError = trys.m_half1.m_ptryBest->m_fError + trys.m_half2.m_ptryBest->m_fError;
}
else
{
// else, find the next best halves that are in differential range
for (DifferentialTrys::Try *ptry1 = &trys.m_half1.m_atry[0];
ptry1 < &trys.m_half1.m_atry[trys.m_half1.m_uiTrys];
ptry1++)
{
for (DifferentialTrys::Try *ptry2 = &trys.m_half2.m_atry[0];
ptry2 < &trys.m_half2.m_atry[trys.m_half2.m_uiTrys];
ptry2++)
{
iDRed = ptry2->m_iRed - ptry1->m_iRed;
bool boolValidRedDelta = iDRed <= 3 && iDRed >= -4;
iDGreen = ptry2->m_iGreen - ptry1->m_iGreen;
bool boolValidGreenDelta = iDGreen <= 3 && iDGreen >= -4;
iDBlue = ptry2->m_iBlue - ptry1->m_iBlue;
bool boolValidBlueDelta = iDBlue <= 3 && iDBlue >= -4;
if (boolValidRedDelta && boolValidGreenDelta && boolValidBlueDelta)
{
float fError = ptry1->m_fError + ptry2->m_fError;
if (fError < encodingTry.m_fError)
{
encodingTry.m_fError = fError;
ptryBest1 = ptry1;
ptryBest2 = ptry2;
}
}
}
}
assert(encodingTry.m_fError < FLT_MAX);
assert(ptryBest1 != nullptr);
assert(ptryBest2 != nullptr);
}
if (encodingTry.m_fError < m_fError)
{
m_mode = MODE_ETC1;
m_boolDiff = true;
m_boolFlip = encodingTry.m_boolFlip;
m_frgbaColor1 = ColorFloatRGBA::ConvertFromRGB5((unsigned char)ptryBest1->m_iRed, (unsigned char)ptryBest1->m_iGreen, (unsigned char)ptryBest1->m_iBlue);
m_frgbaColor2 = ColorFloatRGBA::ConvertFromRGB5((unsigned char)ptryBest2->m_iRed, (unsigned char)ptryBest2->m_iGreen, (unsigned char)ptryBest2->m_iBlue);
m_uiCW1 = ptryBest1->m_uiCW;
m_uiCW2 = ptryBest2->m_uiCW;
for (unsigned int uiPixelOrder = 0; uiPixelOrder < PIXELS / 2; uiPixelOrder++)
{
unsigned int uiPixel1 = pauiPixelMapping1[uiPixelOrder];
unsigned int uiPixel2 = pauiPixelMapping2[uiPixelOrder];
unsigned int uiSelector1 = ptryBest1->m_auiSelectors[uiPixelOrder];
unsigned int uiSelector2 = ptryBest2->m_auiSelectors[uiPixelOrder];
m_auiSelectors[uiPixel1] = uiSelector1;
m_auiSelectors[uiPixel2] = ptryBest2->m_auiSelectors[uiPixelOrder];
float fDeltaRGB1 = s_aafCwTable[m_uiCW1][uiSelector1];
float fDeltaRGB2 = s_aafCwTable[m_uiCW2][uiSelector2];
m_afrgbaDecodedColors[uiPixel1] = (m_frgbaColor1 + fDeltaRGB1).ClampRGB();
m_afrgbaDecodedColors[uiPixel2] = (m_frgbaColor2 + fDeltaRGB2).ClampRGB();
}
m_fError1 = ptryBest1->m_fError;
m_fError2 = ptryBest2->m_fError;
m_boolSeverelyBentDifferentialColors = trys.m_boolSeverelyBentColors;
m_fError = m_fError1 + m_fError2;
// sanity check
{
int iRed1 = m_frgbaColor1.IntRed(31.0f);
int iGreen1 = m_frgbaColor1.IntGreen(31.0f);
int iBlue1 = m_frgbaColor1.IntBlue(31.0f);
int iRed2 = m_frgbaColor2.IntRed(31.0f);
int iGreen2 = m_frgbaColor2.IntGreen(31.0f);
int iBlue2 = m_frgbaColor2.IntBlue(31.0f);
iDRed = iRed2 - iRed1;
iDGreen = iGreen2 - iGreen1;
iDBlue = iBlue2 - iBlue1;
assert(iDRed >= -4 && iDRed < 4);
assert(iDGreen >= -4 && iDGreen < 4);
assert(iDBlue >= -4 && iDBlue < 4);
}
}
}
// ----------------------------------------------------------------------------------------------------
// try an ETC1 differential mode encoding for a half of a 4x4 block
// vary the basecolor components using a radius
//
void Block4x4Encoding_ETC1::TryDifferentialHalf(DifferentialTrys::Half *a_phalf)
{
a_phalf->m_ptryBest = nullptr;
float fBestTryError = FLT_MAX;
a_phalf->m_uiTrys = 0;
for (int iRed = a_phalf->m_iRed - (int)a_phalf->m_uiRadius;
iRed <= a_phalf->m_iRed + (int)a_phalf->m_uiRadius;
iRed++)
{
assert(iRed >= 0 && iRed <= 31);
for (int iGreen = a_phalf->m_iGreen - (int)a_phalf->m_uiRadius;
iGreen <= a_phalf->m_iGreen + (int)a_phalf->m_uiRadius;
iGreen++)
{
assert(iGreen >= 0 && iGreen <= 31);
for (int iBlue = a_phalf->m_iBlue - (int)a_phalf->m_uiRadius;
iBlue <= a_phalf->m_iBlue + (int)a_phalf->m_uiRadius;
iBlue++)
{
assert(iBlue >= 0 && iBlue <= 31);
DifferentialTrys::Try *ptry = &a_phalf->m_atry[a_phalf->m_uiTrys];
assert(ptry < &a_phalf->m_atry[DifferentialTrys::Half::MAX_TRYS]);
ptry->m_iRed = iRed;
ptry->m_iGreen = iGreen;
ptry->m_iBlue = iBlue;
ptry->m_fError = FLT_MAX;
ColorFloatRGBA frgbaColor = ColorFloatRGBA::ConvertFromRGB5((unsigned char)iRed, (unsigned char)iGreen, (unsigned char)iBlue);
// try each CW
for (unsigned int uiCW = 0; uiCW < CW_RANGES; uiCW++)
{
unsigned int auiPixelSelectors[PIXELS / 2];
ColorFloatRGBA afrgbaDecodedPixels[PIXELS / 2];
float afPixelErrors[PIXELS / 2] = { FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX,
FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX };
// pre-compute decoded pixels for each selector
ColorFloatRGBA afrgbaSelectors[SELECTORS];
assert(SELECTORS == 4);
afrgbaSelectors[0] = (frgbaColor + s_aafCwTable[uiCW][0]).ClampRGB();
afrgbaSelectors[1] = (frgbaColor + s_aafCwTable[uiCW][1]).ClampRGB();
afrgbaSelectors[2] = (frgbaColor + s_aafCwTable[uiCW][2]).ClampRGB();
afrgbaSelectors[3] = (frgbaColor + s_aafCwTable[uiCW][3]).ClampRGB();
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
ColorFloatRGBA *pfrgbaSourcePixel = &m_pafrgbaSource[a_phalf->m_pauiPixelMapping[uiPixel]];
ColorFloatRGBA frgbaDecodedPixel;
for (unsigned int uiSelector = 0; uiSelector < SELECTORS; uiSelector++)
{
frgbaDecodedPixel = afrgbaSelectors[uiSelector];
float fPixelError;
fPixelError = CalcPixelError(frgbaDecodedPixel, m_afDecodedAlphas[a_phalf->m_pauiPixelMapping[uiPixel]],
*pfrgbaSourcePixel);
if (fPixelError < afPixelErrors[uiPixel])
{
auiPixelSelectors[uiPixel] = uiSelector;
afrgbaDecodedPixels[uiPixel] = frgbaDecodedPixel;
afPixelErrors[uiPixel] = fPixelError;
}
}
}
// add up all pixel errors
float fCWError = 0.0f;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
fCWError += afPixelErrors[uiPixel];
}
// if best CW so far
if (fCWError < ptry->m_fError)
{
ptry->m_uiCW = uiCW;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
ptry->m_auiSelectors[uiPixel] = auiPixelSelectors[uiPixel];
}
ptry->m_fError = fCWError;
}
}
if (ptry->m_fError < fBestTryError)
{
a_phalf->m_ptryBest = ptry;
fBestTryError = ptry->m_fError;
}
assert(ptry->m_fError < FLT_MAX);
a_phalf->m_uiTrys++;
}
}
}
}
// ----------------------------------------------------------------------------------------------------
// try an ETC1 individual mode encoding
// use a_boolFlip to set the encoding F bit
// use a_uiRadius to alter basecolor components in the range[-a_uiRadius:a_uiRadius]
// replace the encoding if the encoding error is less than previous encoding
//
void Block4x4Encoding_ETC1::TryIndividual(bool a_boolFlip, unsigned int a_uiRadius)
{
ColorFloatRGBA frgbaColor1;
ColorFloatRGBA frgbaColor2;
const unsigned int *pauiPixelMapping1;
const unsigned int *pauiPixelMapping2;
if (a_boolFlip)
{
frgbaColor1 = m_frgbaSourceAverageTop;
frgbaColor2 = m_frgbaSourceAverageBottom;
pauiPixelMapping1 = s_auiTopPixelMapping;
pauiPixelMapping2 = s_auiBottomPixelMapping;
}
else
{
frgbaColor1 = m_frgbaSourceAverageLeft;
frgbaColor2 = m_frgbaSourceAverageRight;
pauiPixelMapping1 = s_auiLeftPixelMapping;
pauiPixelMapping2 = s_auiRightPixelMapping;
}
IndividualTrys trys(frgbaColor1, frgbaColor2, pauiPixelMapping1, pauiPixelMapping2, a_uiRadius);
Block4x4Encoding_ETC1 encodingTry = *this;
encodingTry.m_boolFlip = a_boolFlip;
encodingTry.TryIndividualHalf(&trys.m_half1);
encodingTry.TryIndividualHalf(&trys.m_half2);
// use the best of each half
IndividualTrys::Try *ptryBest1 = trys.m_half1.m_ptryBest;
IndividualTrys::Try *ptryBest2 = trys.m_half2.m_ptryBest;
encodingTry.m_fError = trys.m_half1.m_ptryBest->m_fError + trys.m_half2.m_ptryBest->m_fError;
if (encodingTry.m_fError < m_fError)
{
m_mode = MODE_ETC1;
m_boolDiff = false;
m_boolFlip = encodingTry.m_boolFlip;
m_frgbaColor1 = ColorFloatRGBA::ConvertFromRGB4((unsigned char)ptryBest1->m_iRed, (unsigned char)ptryBest1->m_iGreen, (unsigned char)ptryBest1->m_iBlue);
m_frgbaColor2 = ColorFloatRGBA::ConvertFromRGB4((unsigned char)ptryBest2->m_iRed, (unsigned char)ptryBest2->m_iGreen, (unsigned char)ptryBest2->m_iBlue);
m_uiCW1 = ptryBest1->m_uiCW;
m_uiCW2 = ptryBest2->m_uiCW;
for (unsigned int uiPixelOrder = 0; uiPixelOrder < PIXELS / 2; uiPixelOrder++)
{
unsigned int uiPixel1 = pauiPixelMapping1[uiPixelOrder];
unsigned int uiPixel2 = pauiPixelMapping2[uiPixelOrder];
unsigned int uiSelector1 = ptryBest1->m_auiSelectors[uiPixelOrder];
unsigned int uiSelector2 = ptryBest2->m_auiSelectors[uiPixelOrder];
m_auiSelectors[uiPixel1] = uiSelector1;
m_auiSelectors[uiPixel2] = ptryBest2->m_auiSelectors[uiPixelOrder];
float fDeltaRGB1 = s_aafCwTable[m_uiCW1][uiSelector1];
float fDeltaRGB2 = s_aafCwTable[m_uiCW2][uiSelector2];
m_afrgbaDecodedColors[uiPixel1] = (m_frgbaColor1 + fDeltaRGB1).ClampRGB();
m_afrgbaDecodedColors[uiPixel2] = (m_frgbaColor2 + fDeltaRGB2).ClampRGB();
}
m_fError1 = ptryBest1->m_fError;
m_fError2 = ptryBest2->m_fError;
m_fError = m_fError1 + m_fError2;
}
}
// ----------------------------------------------------------------------------------------------------
// try an ETC1 differential mode encoding for a half of a 4x4 block
// vary the basecolor components using a radius
//
void Block4x4Encoding_ETC1::TryIndividualHalf(IndividualTrys::Half *a_phalf)
{
a_phalf->m_ptryBest = nullptr;
float fBestTryError = FLT_MAX;
a_phalf->m_uiTrys = 0;
for (int iRed = a_phalf->m_iRed - (int)a_phalf->m_uiRadius;
iRed <= a_phalf->m_iRed + (int)a_phalf->m_uiRadius;
iRed++)
{
assert(iRed >= 0 && iRed <= 15);
for (int iGreen = a_phalf->m_iGreen - (int)a_phalf->m_uiRadius;
iGreen <= a_phalf->m_iGreen + (int)a_phalf->m_uiRadius;
iGreen++)
{
assert(iGreen >= 0 && iGreen <= 15);
for (int iBlue = a_phalf->m_iBlue - (int)a_phalf->m_uiRadius;
iBlue <= a_phalf->m_iBlue + (int)a_phalf->m_uiRadius;
iBlue++)
{
assert(iBlue >= 0 && iBlue <= 15);
IndividualTrys::Try *ptry = &a_phalf->m_atry[a_phalf->m_uiTrys];
assert(ptry < &a_phalf->m_atry[IndividualTrys::Half::MAX_TRYS]);
ptry->m_iRed = iRed;
ptry->m_iGreen = iGreen;
ptry->m_iBlue = iBlue;
ptry->m_fError = FLT_MAX;
ColorFloatRGBA frgbaColor = ColorFloatRGBA::ConvertFromRGB4((unsigned char)iRed, (unsigned char)iGreen, (unsigned char)iBlue);
// try each CW
for (unsigned int uiCW = 0; uiCW < CW_RANGES; uiCW++)
{
unsigned int auiPixelSelectors[PIXELS / 2];
ColorFloatRGBA afrgbaDecodedPixels[PIXELS / 2];
float afPixelErrors[PIXELS / 2] = { FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX,
FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX };
// pre-compute decoded pixels for each selector
ColorFloatRGBA afrgbaSelectors[SELECTORS];
assert(SELECTORS == 4);
afrgbaSelectors[0] = (frgbaColor + s_aafCwTable[uiCW][0]).ClampRGB();
afrgbaSelectors[1] = (frgbaColor + s_aafCwTable[uiCW][1]).ClampRGB();
afrgbaSelectors[2] = (frgbaColor + s_aafCwTable[uiCW][2]).ClampRGB();
afrgbaSelectors[3] = (frgbaColor + s_aafCwTable[uiCW][3]).ClampRGB();
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
ColorFloatRGBA *pfrgbaSourcePixel = &m_pafrgbaSource[a_phalf->m_pauiPixelMapping[uiPixel]];
ColorFloatRGBA frgbaDecodedPixel;
for (unsigned int uiSelector = 0; uiSelector < SELECTORS; uiSelector++)
{
frgbaDecodedPixel = afrgbaSelectors[uiSelector];
float fPixelError;
fPixelError = CalcPixelError(frgbaDecodedPixel, m_afDecodedAlphas[a_phalf->m_pauiPixelMapping[uiPixel]],
*pfrgbaSourcePixel);
if (fPixelError < afPixelErrors[uiPixel])
{
auiPixelSelectors[uiPixel] = uiSelector;
afrgbaDecodedPixels[uiPixel] = frgbaDecodedPixel;
afPixelErrors[uiPixel] = fPixelError;
}
}
}
// add up all pixel errors
float fCWError = 0.0f;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
fCWError += afPixelErrors[uiPixel];
}
// if best CW so far
if (fCWError < ptry->m_fError)
{
ptry->m_uiCW = uiCW;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
ptry->m_auiSelectors[uiPixel] = auiPixelSelectors[uiPixel];
}
ptry->m_fError = fCWError;
}
}
if (ptry->m_fError < fBestTryError)
{
a_phalf->m_ptryBest = ptry;
fBestTryError = ptry->m_fError;
}
assert(ptry->m_fError < FLT_MAX);
a_phalf->m_uiTrys++;
}
}
}
}
// ----------------------------------------------------------------------------------------------------
// try version 1 of the degenerate search
// degenerate encodings use basecolor movement and a subset of the selectors to find useful encodings
// each subsequent version of the degenerate search uses more basecolor movement and is less likely to
// be successfull
//
void Block4x4Encoding_ETC1::TryDegenerates1(void)
{
TryDifferential(m_boolMostLikelyFlip, 1, -2, 0);
TryDifferential(m_boolMostLikelyFlip, 1, 2, 0);
TryDifferential(m_boolMostLikelyFlip, 1, 0, 2);
TryDifferential(m_boolMostLikelyFlip, 1, 0, -2);
}
// ----------------------------------------------------------------------------------------------------
// try version 2 of the degenerate search
// degenerate encodings use basecolor movement and a subset of the selectors to find useful encodings
// each subsequent version of the degenerate search uses more basecolor movement and is less likely to
// be successfull
//
void Block4x4Encoding_ETC1::TryDegenerates2(void)
{
TryDifferential(!m_boolMostLikelyFlip, 1, -2, 0);
TryDifferential(!m_boolMostLikelyFlip, 1, 2, 0);
TryDifferential(!m_boolMostLikelyFlip, 1, 0, 2);
TryDifferential(!m_boolMostLikelyFlip, 1, 0, -2);
}
// ----------------------------------------------------------------------------------------------------
// try version 3 of the degenerate search
// degenerate encodings use basecolor movement and a subset of the selectors to find useful encodings
// each subsequent version of the degenerate search uses more basecolor movement and is less likely to
// be successfull
//
void Block4x4Encoding_ETC1::TryDegenerates3(void)
{
TryDifferential(m_boolMostLikelyFlip, 1, -2, -2);
TryDifferential(m_boolMostLikelyFlip, 1, -2, 2);
TryDifferential(m_boolMostLikelyFlip, 1, 2, -2);
TryDifferential(m_boolMostLikelyFlip, 1, 2, 2);
}
// ----------------------------------------------------------------------------------------------------
// try version 4 of the degenerate search
// degenerate encodings use basecolor movement and a subset of the selectors to find useful encodings
// each subsequent version of the degenerate search uses more basecolor movement and is less likely to
// be successfull
//
void Block4x4Encoding_ETC1::TryDegenerates4(void)
{
TryDifferential(m_boolMostLikelyFlip, 1, -4, 0);
TryDifferential(m_boolMostLikelyFlip, 1, 4, 0);
TryDifferential(m_boolMostLikelyFlip, 1, 0, 4);
TryDifferential(m_boolMostLikelyFlip, 1, 0, -4);
}
// ----------------------------------------------------------------------------------------------------
// find the best selector for each pixel based on a particular basecolor and CW that have been previously set
// calculate the selectors for each half of the block separately
// set the block error as the sum of each half's error
//
void Block4x4Encoding_ETC1::CalculateSelectors()
{
if (m_boolFlip)
{
CalculateHalfOfTheSelectors(0, s_auiTopPixelMapping);
CalculateHalfOfTheSelectors(1, s_auiBottomPixelMapping);
}
else
{
CalculateHalfOfTheSelectors(0, s_auiLeftPixelMapping);
CalculateHalfOfTheSelectors(1, s_auiRightPixelMapping);
}
m_fError = m_fError1 + m_fError2;
}
// ----------------------------------------------------------------------------------------------------
// choose best selectors for half of the block
// calculate the error for half of the block
//
void Block4x4Encoding_ETC1::CalculateHalfOfTheSelectors(unsigned int a_uiHalf,
const unsigned int *pauiPixelMapping)
{
static const bool DEBUG_PRINT = false;
ColorFloatRGBA *pfrgbaColor = a_uiHalf ? &m_frgbaColor2 : &m_frgbaColor1;
unsigned int *puiCW = a_uiHalf ? &m_uiCW2 : &m_uiCW1;
float *pfHalfError = a_uiHalf ? &m_fError2 : &m_fError1;
*pfHalfError = FLT_MAX;
// try each CW
for (unsigned int uiCW = 0; uiCW < CW_RANGES; uiCW++)
{
if (DEBUG_PRINT)
{
printf("\ncw=%u\n", uiCW);
}
unsigned int auiPixelSelectors[PIXELS / 2];
ColorFloatRGBA afrgbaDecodedPixels[PIXELS / 2];
float afPixelErrors[PIXELS / 2] = { FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX, FLT_MAX };
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
if (DEBUG_PRINT)
{
printf("\tsource [%.2f,%.2f,%.2f]\n", m_pafrgbaSource[pauiPixelMapping[uiPixel]].fR,
m_pafrgbaSource[pauiPixelMapping[uiPixel]].fG, m_pafrgbaSource[pauiPixelMapping[uiPixel]].fB);
}
ColorFloatRGBA *pfrgbaSourcePixel = &m_pafrgbaSource[pauiPixelMapping[uiPixel]];
ColorFloatRGBA frgbaDecodedPixel;
for (unsigned int uiSelector = 0; uiSelector < SELECTORS; uiSelector++)
{
float fDeltaRGB = s_aafCwTable[uiCW][uiSelector];
frgbaDecodedPixel = (*pfrgbaColor + fDeltaRGB).ClampRGB();
float fPixelError;
fPixelError = CalcPixelError(frgbaDecodedPixel, m_afDecodedAlphas[pauiPixelMapping[uiPixel]],
*pfrgbaSourcePixel);
if (DEBUG_PRINT)
{
printf("\tpixel %u, index %u [%.2f,%.2f,%.2f], error %.2f", uiPixel, uiSelector,
frgbaDecodedPixel.fR,
frgbaDecodedPixel.fG,
frgbaDecodedPixel.fB,
fPixelError);
}
if (fPixelError < afPixelErrors[uiPixel])
{
if (DEBUG_PRINT)
{
printf(" *");
}
auiPixelSelectors[uiPixel] = uiSelector;
afrgbaDecodedPixels[uiPixel] = frgbaDecodedPixel;
afPixelErrors[uiPixel] = fPixelError;
}
if (DEBUG_PRINT)
{
printf("\n");
}
}
}
// add up all pixel errors
float fCWError = 0.0f;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
fCWError += afPixelErrors[uiPixel];
}
if (DEBUG_PRINT)
{
printf("\terror %.2f\n", fCWError);
}
// if best CW so far
if (fCWError < *pfHalfError)
{
*pfHalfError = fCWError;
*puiCW = uiCW;
for (unsigned int uiPixel = 0; uiPixel < 8; uiPixel++)
{
m_auiSelectors[pauiPixelMapping[uiPixel]] = auiPixelSelectors[uiPixel];
m_afrgbaDecodedColors[pauiPixelMapping[uiPixel]] = afrgbaDecodedPixels[uiPixel];
}
}
}
}
// ----------------------------------------------------------------------------------------------------
// set the encoding bits based on encoding state
//
void Block4x4Encoding_ETC1::SetEncodingBits(void)
{
assert(m_mode == MODE_ETC1);
if (m_boolDiff)
{
int iRed1 = m_frgbaColor1.IntRed(31.0f);
int iGreen1 = m_frgbaColor1.IntGreen(31.0f);
int iBlue1 = m_frgbaColor1.IntBlue(31.0f);
int iRed2 = m_frgbaColor2.IntRed(31.0f);
int iGreen2 = m_frgbaColor2.IntGreen(31.0f);
int iBlue2 = m_frgbaColor2.IntBlue(31.0f);
int iDRed2 = iRed2 - iRed1;
int iDGreen2 = iGreen2 - iGreen1;
int iDBlue2 = iBlue2 - iBlue1;
assert(iDRed2 >= -4 && iDRed2 < 4);
assert(iDGreen2 >= -4 && iDGreen2 < 4);
assert(iDBlue2 >= -4 && iDBlue2 < 4);
m_pencodingbitsRGB8->differential.red1 = (unsigned int)iRed1;
m_pencodingbitsRGB8->differential.green1 = (unsigned int)iGreen1;
m_pencodingbitsRGB8->differential.blue1 = (unsigned int)iBlue1;
m_pencodingbitsRGB8->differential.dred2 = iDRed2;
m_pencodingbitsRGB8->differential.dgreen2 = iDGreen2;
m_pencodingbitsRGB8->differential.dblue2 = iDBlue2;
}
else
{
m_pencodingbitsRGB8->individual.red1 = (unsigned int)m_frgbaColor1.IntRed(15.0f);
m_pencodingbitsRGB8->individual.green1 = (unsigned int)m_frgbaColor1.IntGreen(15.0f);
m_pencodingbitsRGB8->individual.blue1 = (unsigned int)m_frgbaColor1.IntBlue(15.0f);
m_pencodingbitsRGB8->individual.red2 = (unsigned int)m_frgbaColor2.IntRed(15.0f);
m_pencodingbitsRGB8->individual.green2 = (unsigned int)m_frgbaColor2.IntGreen(15.0f);
m_pencodingbitsRGB8->individual.blue2 = (unsigned int)m_frgbaColor2.IntBlue(15.0f);
}
m_pencodingbitsRGB8->individual.cw1 = m_uiCW1;
m_pencodingbitsRGB8->individual.cw2 = m_uiCW2;
SetEncodingBits_Selectors();
m_pencodingbitsRGB8->individual.diff = (unsigned int)m_boolDiff;
m_pencodingbitsRGB8->individual.flip = (unsigned int)m_boolFlip;
}
// ----------------------------------------------------------------------------------------------------
// set the selectors in the encoding bits
//
void Block4x4Encoding_ETC1::SetEncodingBits_Selectors(void)
{
m_pencodingbitsRGB8->individual.selectors = 0;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
unsigned int uiSelector = m_auiSelectors[uiPixel];
// set index msb
m_pencodingbitsRGB8->individual.selectors |= (uiSelector >> 1) << (uiPixel ^ 8);
// set index lsb
m_pencodingbitsRGB8->individual.selectors |= (uiSelector & 1) << ((16 + uiPixel) ^ 8);
}
}
// ----------------------------------------------------------------------------------------------------
// set the decoded colors and decoded alpha based on the encoding state
//
void Block4x4Encoding_ETC1::Decode(void)
{
const unsigned int *pauiPixelOrder = m_boolFlip ? s_auiPixelOrderFlip1 : s_auiPixelOrderFlip0;
for (unsigned int uiPixelOrder = 0; uiPixelOrder < PIXELS; uiPixelOrder++)
{
ColorFloatRGBA *pfrgbaCenter = uiPixelOrder < 8 ? &m_frgbaColor1 : &m_frgbaColor2;
unsigned int uiCW = uiPixelOrder < 8 ? m_uiCW1 : m_uiCW2;
unsigned int uiPixel = pauiPixelOrder[uiPixelOrder];
float fDelta = s_aafCwTable[uiCW][m_auiSelectors[uiPixel]];
m_afrgbaDecodedColors[uiPixel] = (*pfrgbaCenter + fDelta).ClampRGB();
m_afDecodedAlphas[uiPixel] = 1.0f;
}
}
// ----------------------------------------------------------------------------------------------------
//
} // namespace Etc
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