godot/thirdparty/etc2comp/EtcBlock4x4Encoding_R11.cpp

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/*
* 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_R11.cpp
Block4x4Encoding_R11 is the encoder to use when targetting file format R11 and SR11 (signed R11).
*/
#include "EtcConfig.h"
#include "EtcBlock4x4Encoding_R11.h"
#include "EtcBlock4x4EncodingBits.h"
#include "EtcBlock4x4.h"
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <float.h>
#include <limits>
namespace Etc
{
// modifier values to use for R11, SR11, RG11 and SRG11
float Block4x4Encoding_R11::s_aafModifierTable[MODIFIER_TABLE_ENTRYS][SELECTORS]
{
{ -3.0f / 255.0f, -6.0f / 255.0f, -9.0f / 255.0f, -15.0f / 255.0f, 2.0f / 255.0f, 5.0f / 255.0f, 8.0f / 255.0f, 14.0f / 255.0f },
{ -3.0f / 255.0f, -7.0f / 255.0f, -10.0f / 255.0f, -13.0f / 255.0f, 2.0f / 255.0f, 6.0f / 255.0f, 9.0f / 255.0f, 12.0f / 255.0f },
{ -2.0f / 255.0f, -5.0f / 255.0f, -8.0f / 255.0f, -13.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 12.0f / 255.0f },
{ -2.0f / 255.0f, -4.0f / 255.0f, -6.0f / 255.0f, -13.0f / 255.0f, 1.0f / 255.0f, 3.0f / 255.0f, 5.0f / 255.0f, 12.0f / 255.0f },
{ -3.0f / 255.0f, -6.0f / 255.0f, -8.0f / 255.0f, -12.0f / 255.0f, 2.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f, 11.0f / 255.0f },
{ -3.0f / 255.0f, -7.0f / 255.0f, -9.0f / 255.0f, -11.0f / 255.0f, 2.0f / 255.0f, 6.0f / 255.0f, 8.0f / 255.0f, 10.0f / 255.0f },
{ -4.0f / 255.0f, -7.0f / 255.0f, -8.0f / 255.0f, -11.0f / 255.0f, 3.0f / 255.0f, 6.0f / 255.0f, 7.0f / 255.0f, 10.0f / 255.0f },
{ -3.0f / 255.0f, -5.0f / 255.0f, -8.0f / 255.0f, -11.0f / 255.0f, 2.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 10.0f / 255.0f },
{ -2.0f / 255.0f, -6.0f / 255.0f, -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f, 9.0f / 255.0f },
{ -2.0f / 255.0f, -5.0f / 255.0f, -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 7.0f / 255.0f, 9.0f / 255.0f },
{ -2.0f / 255.0f, -4.0f / 255.0f, -8.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 3.0f / 255.0f, 7.0f / 255.0f, 9.0f / 255.0f },
{ -2.0f / 255.0f, -5.0f / 255.0f, -7.0f / 255.0f, -10.0f / 255.0f, 1.0f / 255.0f, 4.0f / 255.0f, 6.0f / 255.0f, 9.0f / 255.0f },
{ -3.0f / 255.0f, -4.0f / 255.0f, -7.0f / 255.0f, -10.0f / 255.0f, 2.0f / 255.0f, 3.0f / 255.0f, 6.0f / 255.0f, 9.0f / 255.0f },
{ -1.0f / 255.0f, -2.0f / 255.0f, -3.0f / 255.0f, -10.0f / 255.0f, 0.0f / 255.0f, 1.0f / 255.0f, 2.0f / 255.0f, 9.0f / 255.0f },
{ -4.0f / 255.0f, -6.0f / 255.0f, -8.0f / 255.0f, -9.0f / 255.0f, 3.0f / 255.0f, 5.0f / 255.0f, 7.0f / 255.0f, 8.0f / 255.0f },
{ -3.0f / 255.0f, -5.0f / 255.0f, -7.0f / 255.0f, -9.0f / 255.0f, 2.0f / 255.0f, 4.0f / 255.0f, 6.0f / 255.0f, 8.0f / 255.0f }
};
// ----------------------------------------------------------------------------------------------------
//
Block4x4Encoding_R11::Block4x4Encoding_R11(void)
{
m_pencodingbitsR11 = nullptr;
}
Block4x4Encoding_R11::~Block4x4Encoding_R11(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_R11::InitFromSource(Block4x4 *a_pblockParent,
ColorFloatRGBA *a_pafrgbaSource,
unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric)
{
Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric);
m_pencodingbitsR11 = (Block4x4EncodingBits_R11 *)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_R11::InitFromEncodingBits(Block4x4 *a_pblockParent,
unsigned char *a_paucEncodingBits,
ColorFloatRGBA *a_pafrgbaSource,
ErrorMetric a_errormetric)
{
m_pencodingbitsR11 = (Block4x4EncodingBits_R11 *)a_paucEncodingBits;
// init RGB portion
Block4x4Encoding_RGB8::InitFromEncodingBits(a_pblockParent,
(unsigned char *)m_pencodingbitsR11,
a_pafrgbaSource,
a_errormetric);
// init R11 portion
{
m_mode = MODE_R11;
if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
{
m_fRedBase = (float)(signed char)m_pencodingbitsR11->data.base;
}
else
{
m_fRedBase = (float)(unsigned char)m_pencodingbitsR11->data.base;
}
m_fRedMultiplier = (float)m_pencodingbitsR11->data.multiplier;
m_uiRedModifierTableIndex = m_pencodingbitsR11->data.table;
unsigned long long int ulliSelectorBits = 0;
ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors0 << 40;
ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors1 << 32;
ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors2 << 24;
ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors3 << 16;
ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors4 << 8;
ulliSelectorBits |= (unsigned long long int)m_pencodingbitsR11->data.selectors5;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
unsigned int uiShift = 45 - (3 * uiPixel);
m_auiRedSelectors[uiPixel] = (ulliSelectorBits >> uiShift) & (SELECTORS - 1);
}
// decode the red channel
// calc red error
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
float fDecodedPixelData = 0.0f;
if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::R11 || a_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
{
fDecodedPixelData = DecodePixelRed(m_fRedBase, m_fRedMultiplier,
m_uiRedModifierTableIndex,
m_auiRedSelectors[uiPixel]);
}
else if (a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || a_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
{
fDecodedPixelData = DecodePixelRed(m_fRedBase + 128, m_fRedMultiplier,
m_uiRedModifierTableIndex,
m_auiRedSelectors[uiPixel]);
}
else
{
assert(0);
}
m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(fDecodedPixelData, 0.0f, 0.0f, 1.0f);
}
CalcBlockError();
}
}
// ----------------------------------------------------------------------------------------------------
// 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_R11::PerformIteration(float a_fEffort)
{
assert(!m_boolDone);
m_mode = MODE_R11;
switch (m_uiEncodingIterations)
{
case 0:
m_fError = FLT_MAX;
m_fRedBlockError = FLT_MAX; // artificially high value
CalculateR11(8, 0.0f, 0.0f);
m_fError = m_fRedBlockError;
break;
case 1:
CalculateR11(8, 2.0f, 1.0f);
m_fError = m_fRedBlockError;
if (a_fEffort <= 24.5f)
{
m_boolDone = true;
}
break;
case 2:
CalculateR11(8, 12.0f, 1.0f);
m_fError = m_fRedBlockError;
if (a_fEffort <= 49.5f)
{
m_boolDone = true;
}
break;
case 3:
CalculateR11(7, 6.0f, 1.0f);
m_fError = m_fRedBlockError;
break;
case 4:
CalculateR11(6, 3.0f, 1.0f);
m_fError = m_fRedBlockError;
break;
case 5:
CalculateR11(5, 1.0f, 0.0f);
m_fError = m_fRedBlockError;
m_boolDone = true;
break;
default:
assert(0);
break;
}
m_uiEncodingIterations++;
SetDoneIfPerfect();
}
// ----------------------------------------------------------------------------------------------------
// find the best combination of base color, multiplier and selectors
//
// a_uiSelectorsUsed limits the number of selector combinations to try
// a_fBaseRadius limits the range of base colors to try
// a_fMultiplierRadius limits the range of multipliers to try
//
void Block4x4Encoding_R11::CalculateR11(unsigned int a_uiSelectorsUsed,
float a_fBaseRadius, float a_fMultiplierRadius)
{
// maps from virtual (monotonic) selector to ETC selector
static const unsigned int auiVirtualSelectorMap[8] = {3, 2, 1, 0, 4, 5, 6, 7};
// find min/max red
float fMinRed = 1.0f;
float fMaxRed = 0.0f;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
// ignore border pixels
float fAlpha = m_pafrgbaSource[uiPixel].fA;
if (isnan(fAlpha))
{
continue;
}
float fRed = m_pafrgbaSource[uiPixel].fR;
if (fRed < fMinRed)
{
fMinRed = fRed;
}
if (fRed > fMaxRed)
{
fMaxRed = fRed;
}
}
assert(fMinRed <= fMaxRed);
float fRedRange = (fMaxRed - fMinRed);
// try each modifier table entry
for (unsigned int uiTableEntry = 0; uiTableEntry < MODIFIER_TABLE_ENTRYS; uiTableEntry++)
{
for (unsigned int uiMinVirtualSelector = 0;
uiMinVirtualSelector <= (8- a_uiSelectorsUsed);
uiMinVirtualSelector++)
{
unsigned int uiMaxVirtualSelector = uiMinVirtualSelector + a_uiSelectorsUsed - 1;
unsigned int uiMinSelector = auiVirtualSelectorMap[uiMinVirtualSelector];
unsigned int uiMaxSelector = auiVirtualSelectorMap[uiMaxVirtualSelector];
float fTableEntryCenter = -s_aafModifierTable[uiTableEntry][uiMinSelector];
float fTableEntryRange = s_aafModifierTable[uiTableEntry][uiMaxSelector] -
s_aafModifierTable[uiTableEntry][uiMinSelector];
float fCenterRatio = fTableEntryCenter / fTableEntryRange;
float fCenter = fMinRed + fCenterRatio*fRedRange;
fCenter = roundf(255.0f * fCenter) / 255.0f;
float fMinBase = fCenter - (a_fBaseRadius / 255.0f);
if (fMinBase < 0.0f)
{
fMinBase = 0.0f;
}
float fMaxBase = fCenter + (a_fBaseRadius / 255.0f);
if (fMaxBase > 1.0f)
{
fMaxBase = 1.0f;
}
for (float fBase = fMinBase; fBase <= fMaxBase; fBase += (0.999999f / 255.0f))
{
float fRangeMultiplier = roundf(fRedRange / fTableEntryRange);
float fMinMultiplier = fRangeMultiplier - a_fMultiplierRadius;
if (fMinMultiplier < 1.0f)
{
fMinMultiplier = 0.0f;
}
else if (fMinMultiplier > 15.0f)
{
fMinMultiplier = 15.0f;
}
float fMaxMultiplier = fRangeMultiplier + a_fMultiplierRadius;
if (fMaxMultiplier < 1.0f)
{
fMaxMultiplier = 1.0f;
}
else if (fMaxMultiplier > 15.0f)
{
fMaxMultiplier = 15.0f;
}
for (float fMultiplier = fMinMultiplier; fMultiplier <= fMaxMultiplier; fMultiplier += 1.0f)
{
// find best selector for each pixel
unsigned int auiBestSelectors[PIXELS];
float afBestRedError[PIXELS];
float afBestPixelRed[PIXELS];
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
float fBestPixelRedError = FLT_MAX;
for (unsigned int uiSelector = 0; uiSelector < SELECTORS; uiSelector++)
{
float fPixelRed = DecodePixelRed(fBase * 255.0f, fMultiplier, uiTableEntry, uiSelector);
ColorFloatRGBA frgba(fPixelRed, m_pafrgbaSource[uiPixel].fG,0.0f,1.0f);
float fPixelRedError = CalcPixelError(frgba, 1.0f, m_pafrgbaSource[uiPixel]);
if (fPixelRedError < fBestPixelRedError)
{
fBestPixelRedError = fPixelRedError;
auiBestSelectors[uiPixel] = uiSelector;
afBestRedError[uiPixel] = fBestPixelRedError;
afBestPixelRed[uiPixel] = fPixelRed;
}
}
}
float fBlockError = 0.0f;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
fBlockError += afBestRedError[uiPixel];
}
if (fBlockError < m_fRedBlockError)
{
m_fRedBlockError = fBlockError;
if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
{
m_fRedBase = 255.0f * fBase;
}
else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
{
m_fRedBase = (fBase * 255) - 128;
}
else
{
assert(0);
}
m_fRedMultiplier = fMultiplier;
m_uiRedModifierTableIndex = uiTableEntry;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
m_auiRedSelectors[uiPixel] = auiBestSelectors[uiPixel];
float fBestPixelRed = afBestPixelRed[uiPixel];
m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(fBestPixelRed, 0.0f, 0.0f, 1.0f);
m_afDecodedAlphas[uiPixel] = 1.0f;
}
}
}
}
}
}
}
// ----------------------------------------------------------------------------------------------------
// set the encoding bits based on encoding state
//
void Block4x4Encoding_R11::SetEncodingBits(void)
{
if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::RG11)
{
m_pencodingbitsR11->data.base = (unsigned char)roundf(m_fRedBase);
}
else if (m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_R11 || m_pblockParent->GetImageSource()->GetFormat() == Image::Format::SIGNED_RG11)
{
m_pencodingbitsR11->data.base = (signed char)roundf(m_fRedBase);
}
else
{
assert(0);
}
m_pencodingbitsR11->data.table = m_uiRedModifierTableIndex;
m_pencodingbitsR11->data.multiplier = (unsigned char)roundf(m_fRedMultiplier);
unsigned long long int ulliSelectorBits = 0;
for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++)
{
unsigned int uiShift = 45 - (3 * uiPixel);
ulliSelectorBits |= ((unsigned long long int)m_auiRedSelectors[uiPixel]) << uiShift;
}
m_pencodingbitsR11->data.selectors0 = ulliSelectorBits >> 40;
m_pencodingbitsR11->data.selectors1 = ulliSelectorBits >> 32;
m_pencodingbitsR11->data.selectors2 = ulliSelectorBits >> 24;
m_pencodingbitsR11->data.selectors3 = ulliSelectorBits >> 16;
m_pencodingbitsR11->data.selectors4 = ulliSelectorBits >> 8;
m_pencodingbitsR11->data.selectors5 = ulliSelectorBits;
}
// ----------------------------------------------------------------------------------------------------
//
}