/* * 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_RGBA8.cpp contains: Block4x4Encoding_RGBA8 Block4x4Encoding_RGBA8_Opaque Block4x4Encoding_RGBA8_Transparent These encoders are used when targetting file format RGBA8. Block4x4Encoding_RGBA8_Opaque is used when all pixels in the 4x4 block are opaque Block4x4Encoding_RGBA8_Transparent is used when all pixels in the 4x4 block are transparent Block4x4Encoding_RGBA8 is used when there is a mixture of alphas in the 4x4 block */ #include "EtcConfig.h" #include "EtcBlock4x4Encoding_RGBA8.h" #include "EtcBlock4x4EncodingBits.h" #include "EtcBlock4x4.h" #include <stdio.h> #include <string.h> #include <assert.h> #include <float.h> #include <limits> namespace Etc { // #################################################################################################### // Block4x4Encoding_RGBA8 // #################################################################################################### float Block4x4Encoding_RGBA8::s_aafModifierTable[MODIFIER_TABLE_ENTRYS][ALPHA_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_RGBA8::Block4x4Encoding_RGBA8(void) { m_pencodingbitsA8 = nullptr; } Block4x4Encoding_RGBA8::~Block4x4Encoding_RGBA8(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_RGBA8::InitFromSource(Block4x4 *a_pblockParent, ColorFloatRGBA *a_pafrgbaSource, unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric) { Block4x4Encoding::Init(a_pblockParent, a_pafrgbaSource,a_errormetric); m_pencodingbitsA8 = (Block4x4EncodingBits_A8 *)a_paucEncodingBits; m_pencodingbitsRGB8 = (Block4x4EncodingBits_RGB8 *)(a_paucEncodingBits + sizeof(Block4x4EncodingBits_A8)); } // ---------------------------------------------------------------------------------------------------- // 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_RGBA8::InitFromEncodingBits(Block4x4 *a_pblockParent, unsigned char *a_paucEncodingBits, ColorFloatRGBA *a_pafrgbaSource, ErrorMetric a_errormetric) { m_pencodingbitsA8 = (Block4x4EncodingBits_A8 *)a_paucEncodingBits; m_pencodingbitsRGB8 = (Block4x4EncodingBits_RGB8 *)(a_paucEncodingBits + sizeof(Block4x4EncodingBits_A8)); // init RGB portion Block4x4Encoding_RGB8::InitFromEncodingBits(a_pblockParent, (unsigned char *) m_pencodingbitsRGB8, a_pafrgbaSource, a_errormetric); // init A8 portion // has to be done after InitFromEncodingBits() { m_fBase = m_pencodingbitsA8->data.base / 255.0f; m_fMultiplier = (float)m_pencodingbitsA8->data.multiplier; m_uiModifierTableIndex = m_pencodingbitsA8->data.table; unsigned long long int ulliSelectorBits = 0; ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors0 << 40; ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors1 << 32; ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors2 << 24; ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors3 << 16; ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors4 << 8; ulliSelectorBits |= (unsigned long long int)m_pencodingbitsA8->data.selectors5; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { unsigned int uiShift = 45 - (3 * uiPixel); m_auiAlphaSelectors[uiPixel] = (ulliSelectorBits >> uiShift) & (ALPHA_SELECTORS - 1); } // decode the alphas // calc alpha error m_fError = 0.0f; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { m_afDecodedAlphas[uiPixel] = DecodePixelAlpha(m_fBase, m_fMultiplier, m_uiModifierTableIndex, m_auiAlphaSelectors[uiPixel]); float fDeltaAlpha = m_afDecodedAlphas[uiPixel] - m_pafrgbaSource[uiPixel].fA; m_fError += fDeltaAlpha * fDeltaAlpha; } } // redo error calc to include alpha 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 // // similar to Block4x4Encoding_RGB8_Base::Encode_RGB8(), but with alpha added // void Block4x4Encoding_RGBA8::PerformIteration(float a_fEffort) { assert(!m_boolDone); if (m_uiEncodingIterations == 0) { if (a_fEffort < 24.9f) { CalculateA8(0.0f); } else if (a_fEffort < 49.9f) { CalculateA8(1.0f); } else { CalculateA8(2.0f); } } Block4x4Encoding_RGB8::PerformIteration(a_fEffort); } // ---------------------------------------------------------------------------------------------------- // find the best combination of base alpga, multiplier and selectors // // a_fRadius limits the range of base alpha to try // void Block4x4Encoding_RGBA8::CalculateA8(float a_fRadius) { // find min/max alpha float fMinAlpha = 1.0f; float fMaxAlpha = 0.0f; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { float fAlpha = m_pafrgbaSource[uiPixel].fA; // ignore border pixels if (isnan(fAlpha)) { continue; } if (fAlpha < fMinAlpha) { fMinAlpha = fAlpha; } if (fAlpha > fMaxAlpha) { fMaxAlpha = fAlpha; } } assert(fMinAlpha <= fMaxAlpha); float fAlphaRange = fMaxAlpha - fMinAlpha; // try each modifier table entry m_fError = FLT_MAX; // artificially high value for (unsigned int uiTableEntry = 0; uiTableEntry < MODIFIER_TABLE_ENTRYS; uiTableEntry++) { static const unsigned int MIN_VALUE_SELECTOR = 3; static const unsigned int MAX_VALUE_SELECTOR = 7; float fTableEntryCenter = -s_aafModifierTable[uiTableEntry][MIN_VALUE_SELECTOR]; float fTableEntryRange = s_aafModifierTable[uiTableEntry][MAX_VALUE_SELECTOR] - s_aafModifierTable[uiTableEntry][MIN_VALUE_SELECTOR]; float fCenterRatio = fTableEntryCenter / fTableEntryRange; float fCenter = fMinAlpha + fCenterRatio*fAlphaRange; fCenter = roundf(255.0f * fCenter) / 255.0f; float fMinBase = fCenter - (a_fRadius / 255.0f); if (fMinBase < 0.0f) { fMinBase = 0.0f; } float fMaxBase = fCenter + (a_fRadius / 255.0f); if (fMaxBase > 1.0f) { fMaxBase = 1.0f; } for (float fBase = fMinBase; fBase <= fMaxBase; fBase += (0.999999f / 255.0f)) { float fRangeMultiplier = roundf(fAlphaRange / fTableEntryRange); float fMinMultiplier = fRangeMultiplier - a_fRadius; if (fMinMultiplier < 1.0f) { fMinMultiplier = 1.0f; } else if (fMinMultiplier > 15.0f) { fMinMultiplier = 15.0f; } float fMaxMultiplier = fRangeMultiplier + a_fRadius; 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 afBestAlphaError[PIXELS]; float afBestDecodedAlphas[PIXELS]; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { float fBestPixelAlphaError = FLT_MAX; for (unsigned int uiSelector = 0; uiSelector < ALPHA_SELECTORS; uiSelector++) { float fDecodedAlpha = DecodePixelAlpha(fBase, fMultiplier, uiTableEntry, uiSelector); // border pixels (NAN) should have zero error float fPixelDeltaAlpha = isnan(m_pafrgbaSource[uiPixel].fA) ? 0.0f : fDecodedAlpha - m_pafrgbaSource[uiPixel].fA; float fPixelAlphaError = fPixelDeltaAlpha * fPixelDeltaAlpha; if (fPixelAlphaError < fBestPixelAlphaError) { fBestPixelAlphaError = fPixelAlphaError; auiBestSelectors[uiPixel] = uiSelector; afBestAlphaError[uiPixel] = fBestPixelAlphaError; afBestDecodedAlphas[uiPixel] = fDecodedAlpha; } } } float fBlockError = 0.0f; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { fBlockError += afBestAlphaError[uiPixel]; } if (fBlockError < m_fError) { m_fError = fBlockError; m_fBase = fBase; m_fMultiplier = fMultiplier; m_uiModifierTableIndex = uiTableEntry; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { m_auiAlphaSelectors[uiPixel] = auiBestSelectors[uiPixel]; m_afDecodedAlphas[uiPixel] = afBestDecodedAlphas[uiPixel]; } } } } } } // ---------------------------------------------------------------------------------------------------- // set the encoding bits based on encoding state // void Block4x4Encoding_RGBA8::SetEncodingBits(void) { // set the RGB8 portion Block4x4Encoding_RGB8::SetEncodingBits(); // set the A8 portion { m_pencodingbitsA8->data.base = (unsigned char)roundf(255.0f * m_fBase); m_pencodingbitsA8->data.table = m_uiModifierTableIndex; m_pencodingbitsA8->data.multiplier = (unsigned char)roundf(m_fMultiplier); 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_auiAlphaSelectors[uiPixel]) << uiShift; } m_pencodingbitsA8->data.selectors0 = ulliSelectorBits >> 40; m_pencodingbitsA8->data.selectors1 = ulliSelectorBits >> 32; m_pencodingbitsA8->data.selectors2 = ulliSelectorBits >> 24; m_pencodingbitsA8->data.selectors3 = ulliSelectorBits >> 16; m_pencodingbitsA8->data.selectors4 = ulliSelectorBits >> 8; m_pencodingbitsA8->data.selectors5 = ulliSelectorBits; } } // #################################################################################################### // Block4x4Encoding_RGBA8_Opaque // #################################################################################################### // ---------------------------------------------------------------------------------------------------- // 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_RGBA8_Opaque::PerformIteration(float a_fEffort) { assert(!m_boolDone); if (m_uiEncodingIterations == 0) { m_fError = 0.0f; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { m_afDecodedAlphas[uiPixel] = 1.0f; } } Block4x4Encoding_RGB8::PerformIteration(a_fEffort); } // ---------------------------------------------------------------------------------------------------- // set the encoding bits based on encoding state // void Block4x4Encoding_RGBA8_Opaque::SetEncodingBits(void) { // set the RGB8 portion Block4x4Encoding_RGB8::SetEncodingBits(); // set the A8 portion m_pencodingbitsA8->data.base = 255; m_pencodingbitsA8->data.table = 15; m_pencodingbitsA8->data.multiplier = 15; m_pencodingbitsA8->data.selectors0 = 0xFF; m_pencodingbitsA8->data.selectors1 = 0xFF; m_pencodingbitsA8->data.selectors2 = 0xFF; m_pencodingbitsA8->data.selectors3 = 0xFF; m_pencodingbitsA8->data.selectors4 = 0xFF; m_pencodingbitsA8->data.selectors5 = 0xFF; } // #################################################################################################### // Block4x4Encoding_RGBA8_Transparent // #################################################################################################### // ---------------------------------------------------------------------------------------------------- // 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_RGBA8_Transparent::PerformIteration(float ) { assert(!m_boolDone); assert(m_uiEncodingIterations == 0); m_mode = MODE_ETC1; m_boolDiff = true; m_boolFlip = false; for (unsigned int uiPixel = 0; uiPixel < PIXELS; uiPixel++) { m_afrgbaDecodedColors[uiPixel] = ColorFloatRGBA(); m_afDecodedAlphas[uiPixel] = 0.0f; } m_fError = 0.0f; m_boolDone = true; m_uiEncodingIterations++; } // ---------------------------------------------------------------------------------------------------- // set the encoding bits based on encoding state // void Block4x4Encoding_RGBA8_Transparent::SetEncodingBits(void) { Block4x4Encoding_RGB8::SetEncodingBits(); // set the A8 portion m_pencodingbitsA8->data.base = 0; m_pencodingbitsA8->data.table = 0; m_pencodingbitsA8->data.multiplier = 1; m_pencodingbitsA8->data.selectors0 = 0; m_pencodingbitsA8->data.selectors1 = 0; m_pencodingbitsA8->data.selectors2 = 0; m_pencodingbitsA8->data.selectors3 = 0; m_pencodingbitsA8->data.selectors4 = 0; m_pencodingbitsA8->data.selectors5 = 0; } // ---------------------------------------------------------------------------------------------------- // }