| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkColorSpaceXform_A2B.h" |
| |
| #include "SkColorPriv.h" |
| #include "SkColorSpace_A2B.h" |
| #include "SkColorSpace_XYZ.h" |
| #include "SkColorSpacePriv.h" |
| #include "SkColorSpaceXformPriv.h" |
| #include "SkMakeUnique.h" |
| #include "SkNx.h" |
| #include "SkSRGB.h" |
| #include "SkTypes.h" |
| |
| bool SkColorSpaceXform_A2B::onApply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, |
| const void* src, int count, SkAlphaType alphaType) const { |
| SkRasterPipeline pipeline; |
| switch (srcFormat) { |
| case kBGRA_8888_ColorFormat: |
| pipeline.append(SkRasterPipeline::load_8888, &src); |
| pipeline.append(SkRasterPipeline::swap_rb); |
| break; |
| case kRGBA_8888_ColorFormat: |
| pipeline.append(SkRasterPipeline::load_8888, &src); |
| break; |
| case kRGBA_U16_BE_ColorFormat: |
| pipeline.append(SkRasterPipeline::load_u16_be, &src); |
| break; |
| case kRGB_U16_BE_ColorFormat: |
| pipeline.append(SkRasterPipeline::load_rgb_u16_be, &src); |
| break; |
| default: |
| SkCSXformPrintf("F16/F32 source color format not supported\n"); |
| return false; |
| } |
| |
| pipeline.extend(fElementsPipeline); |
| |
| if (kPremul_SkAlphaType == alphaType) { |
| pipeline.append(SkRasterPipeline::premul); |
| } |
| |
| switch (dstFormat) { |
| case kBGRA_8888_ColorFormat: |
| pipeline.append(SkRasterPipeline::swap_rb); |
| pipeline.append(SkRasterPipeline::store_8888, &dst); |
| break; |
| case kRGBA_8888_ColorFormat: |
| pipeline.append(SkRasterPipeline::store_8888, &dst); |
| break; |
| case kRGBA_F16_ColorFormat: |
| if (!fLinearDstGamma) { |
| return false; |
| } |
| pipeline.append(SkRasterPipeline::store_f16, &dst); |
| break; |
| case kRGBA_F32_ColorFormat: |
| if (!fLinearDstGamma) { |
| return false; |
| } |
| pipeline.append(SkRasterPipeline::store_f32, &dst); |
| break; |
| default: |
| return false; |
| } |
| pipeline.run(0,count); |
| |
| return true; |
| } |
| |
| static inline bool gamma_to_parametric(SkColorSpaceTransferFn* coeffs, const SkGammas& gammas, |
| int channel) { |
| switch (gammas.type(channel)) { |
| case SkGammas::Type::kNamed_Type: |
| return named_to_parametric(coeffs, gammas.data(channel).fNamed); |
| case SkGammas::Type::kValue_Type: |
| value_to_parametric(coeffs, gammas.data(channel).fValue); |
| return true; |
| case SkGammas::Type::kParam_Type: |
| *coeffs = gammas.params(channel); |
| return true; |
| default: |
| return false; |
| } |
| } |
| static inline SkColorSpaceTransferFn invert_parametric(const SkColorSpaceTransferFn& fn) { |
| // Original equation is: y = (ax + b)^g + e for x >= d |
| // y = cx + f otherwise |
| // |
| // so 1st inverse is: (y - e)^(1/g) = ax + b |
| // x = ((y - e)^(1/g) - b) / a |
| // |
| // which can be re-written as: x = (1/a)(y - e)^(1/g) - b/a |
| // x = ((1/a)^g)^(1/g) * (y - e)^(1/g) - b/a |
| // x = ([(1/a)^g]y + [-((1/a)^g)e]) ^ [1/g] + [-b/a] |
| // |
| // and 2nd inverse is: x = (y - f) / c |
| // which can be re-written as: x = [1/c]y + [-f/c] |
| // |
| // and now both can be expressed in terms of the same parametric form as the |
| // original - parameters are enclosed in square brackets. |
| |
| // find inverse for linear segment (if possible) |
| float c, f; |
| if (0.f == fn.fC) { |
| // otherwise assume it should be 0 as it is the lower segment |
| // as y = f is a constant function |
| c = 0.f; |
| f = 0.f; |
| } else { |
| c = 1.f / fn.fC; |
| f = -fn.fF / fn.fC; |
| } |
| // find inverse for the other segment (if possible) |
| float g, a, b, e; |
| if (0.f == fn.fA || 0.f == fn.fG) { |
| // otherwise assume it should be 1 as it is the top segment |
| // as you can't invert the constant functions y = b^g + c, or y = 1 + c |
| g = 1.f; |
| a = 0.f; |
| b = 0.f; |
| e = 1.f; |
| } else { |
| g = 1.f / fn.fG; |
| a = powf(1.f / fn.fA, fn.fG); |
| b = -a * fn.fE; |
| e = -fn.fB / fn.fA; |
| } |
| const float d = fn.fC * fn.fD + fn.fF; |
| return {g, a, b, c, d, e, f}; |
| } |
| |
| SkColorSpaceXform_A2B::SkColorSpaceXform_A2B(SkColorSpace_A2B* srcSpace, |
| SkColorSpace_XYZ* dstSpace) |
| : fLinearDstGamma(kLinear_SkGammaNamed == dstSpace->gammaNamed()) { |
| #if (SkCSXformPrintfDefined) |
| static const char* debugGammaNamed[4] = { |
| "Linear", "SRGB", "2.2", "NonStandard" |
| }; |
| static const char* debugGammas[5] = { |
| "None", "Named", "Value", "Table", "Param" |
| }; |
| #endif |
| int currentChannels; |
| switch (srcSpace->iccType()) { |
| case SkColorSpace_Base::kRGB_ICCTypeFlag: |
| currentChannels = 3; |
| break; |
| case SkColorSpace_Base::kCMYK_ICCTypeFlag: |
| currentChannels = 4; |
| // CMYK images from JPEGs (the only format that supports it) are actually |
| // inverted CMYK, so we need to invert every channel. |
| // TransferFn is y = -x + 1 for x < 1.f, otherwise 0x + 0, ie y = 1 - x for x in [0,1] |
| this->addTransferFns({1.f, 0.f, 0.f, -1.f, 1.f, 0.f, 1.f}, 4); |
| break; |
| default: |
| currentChannels = 0; |
| SkASSERT(false); |
| } |
| // add in all input color space -> PCS xforms |
| for (int i = 0; i < srcSpace->count(); ++i) { |
| const SkColorSpace_A2B::Element& e = srcSpace->element(i); |
| SkASSERT(e.inputChannels() == currentChannels); |
| currentChannels = e.outputChannels(); |
| switch (e.type()) { |
| case SkColorSpace_A2B::Element::Type::kGammaNamed: |
| if (kLinear_SkGammaNamed == e.gammaNamed()) { |
| break; |
| } |
| |
| // take the fast path for 3-channel named gammas |
| if (3 == currentChannels) { |
| if (k2Dot2Curve_SkGammaNamed == e.gammaNamed()) { |
| SkCSXformPrintf("fast path from 2.2\n"); |
| fElementsPipeline.append(SkRasterPipeline::from_2dot2); |
| break; |
| } else if (kSRGB_SkGammaNamed == e.gammaNamed()) { |
| SkCSXformPrintf("fast path from sRGB\n"); |
| // Images should always start the pipeline as unpremul |
| fElementsPipeline.append_from_srgb(kUnpremul_SkAlphaType); |
| break; |
| } |
| } |
| |
| SkCSXformPrintf("Gamma stage added: %s\n", debugGammaNamed[(int)e.gammaNamed()]); |
| SkColorSpaceTransferFn fn; |
| SkAssertResult(named_to_parametric(&fn, e.gammaNamed())); |
| this->addTransferFns(fn, currentChannels); |
| break; |
| case SkColorSpace_A2B::Element::Type::kGammas: { |
| const SkGammas& gammas = e.gammas(); |
| SkCSXformPrintf("Gamma stage added:"); |
| for (int channel = 0; channel < gammas.channels(); ++channel) { |
| SkCSXformPrintf(" %s", debugGammas[(int)gammas.type(channel)]); |
| } |
| SkCSXformPrintf("\n"); |
| bool gammaNeedsRef = false; |
| for (int channel = 0; channel < gammas.channels(); ++channel) { |
| if (SkGammas::Type::kTable_Type == gammas.type(channel)) { |
| SkTableTransferFn table = { |
| gammas.table(channel), |
| gammas.data(channel).fTable.fSize, |
| }; |
| |
| this->addTableFn(table, channel); |
| gammaNeedsRef = true; |
| } else { |
| SkColorSpaceTransferFn fn; |
| SkAssertResult(gamma_to_parametric(&fn, gammas, channel)); |
| this->addTransferFn(fn, channel); |
| } |
| } |
| if (gammaNeedsRef) { |
| fGammaRefs.push_back(sk_ref_sp(&gammas)); |
| } |
| break; |
| } |
| case SkColorSpace_A2B::Element::Type::kCLUT: |
| SkCSXformPrintf("CLUT (%d -> %d) stage added\n", e.colorLUT().inputChannels(), |
| e.colorLUT().outputChannels()); |
| fCLUTs.push_back(sk_ref_sp(&e.colorLUT())); |
| fElementsPipeline.append(SkRasterPipeline::color_lookup_table, |
| fCLUTs.back().get()); |
| break; |
| case SkColorSpace_A2B::Element::Type::kMatrix: |
| if (!e.matrix().isIdentity()) { |
| SkCSXformPrintf("Matrix stage added\n"); |
| addMatrix(e.matrix()); |
| } |
| break; |
| } |
| } |
| |
| // Lab PCS -> XYZ PCS |
| if (SkColorSpace_A2B::PCS::kLAB == srcSpace->pcs()) { |
| SkCSXformPrintf("Lab -> XYZ element added\n"); |
| fElementsPipeline.append(SkRasterPipeline::lab_to_xyz); |
| } |
| |
| // we should now be in XYZ PCS |
| SkASSERT(3 == currentChannels); |
| |
| // and XYZ PCS -> output color space xforms |
| if (!dstSpace->fromXYZD50()->isIdentity()) { |
| addMatrix(*dstSpace->fromXYZD50()); |
| } |
| |
| switch (dstSpace->gammaNamed()) { |
| case kLinear_SkGammaNamed: |
| // do nothing |
| break; |
| case k2Dot2Curve_SkGammaNamed: |
| fElementsPipeline.append(SkRasterPipeline::to_2dot2); |
| break; |
| case kSRGB_SkGammaNamed: |
| fElementsPipeline.append(SkRasterPipeline::to_srgb); |
| break; |
| case kNonStandard_SkGammaNamed: { |
| for (int channel = 0; channel < 3; ++channel) { |
| const SkGammas& gammas = *dstSpace->gammas(); |
| if (SkGammas::Type::kTable_Type == gammas.type(channel)) { |
| static constexpr int kInvTableSize = 256; |
| std::vector<float> storage(kInvTableSize); |
| invert_table_gamma(storage.data(), nullptr, storage.size(), |
| gammas.table(channel), |
| gammas.data(channel).fTable.fSize); |
| SkTableTransferFn table = { |
| storage.data(), |
| (int) storage.size(), |
| }; |
| fTableStorage.push_front(std::move(storage)); |
| |
| this->addTableFn(table, channel); |
| } else { |
| SkColorSpaceTransferFn fn; |
| SkAssertResult(gamma_to_parametric(&fn, gammas, channel)); |
| this->addTransferFn(invert_parametric(fn), channel); |
| } |
| } |
| } |
| break; |
| } |
| } |
| |
| void SkColorSpaceXform_A2B::addTransferFns(const SkColorSpaceTransferFn& fn, int channelCount) { |
| for (int i = 0; i < channelCount; ++i) { |
| this->addTransferFn(fn, i); |
| } |
| } |
| |
| void SkColorSpaceXform_A2B::addTransferFn(const SkColorSpaceTransferFn& fn, int channelIndex) { |
| fTransferFns.push_front(fn); |
| switch (channelIndex) { |
| case 0: |
| fElementsPipeline.append(SkRasterPipeline::parametric_r, &fTransferFns.front()); |
| break; |
| case 1: |
| fElementsPipeline.append(SkRasterPipeline::parametric_g, &fTransferFns.front()); |
| break; |
| case 2: |
| fElementsPipeline.append(SkRasterPipeline::parametric_b, &fTransferFns.front()); |
| break; |
| case 3: |
| fElementsPipeline.append(SkRasterPipeline::parametric_a, &fTransferFns.front()); |
| break; |
| default: |
| SkASSERT(false); |
| } |
| } |
| |
| void SkColorSpaceXform_A2B::addTableFn(const SkTableTransferFn& fn, int channelIndex) { |
| fTableTransferFns.push_front(fn); |
| switch (channelIndex) { |
| case 0: |
| fElementsPipeline.append(SkRasterPipeline::table_r, &fTableTransferFns.front()); |
| break; |
| case 1: |
| fElementsPipeline.append(SkRasterPipeline::table_g, &fTableTransferFns.front()); |
| break; |
| case 2: |
| fElementsPipeline.append(SkRasterPipeline::table_b, &fTableTransferFns.front()); |
| break; |
| case 3: |
| fElementsPipeline.append(SkRasterPipeline::table_a, &fTableTransferFns.front()); |
| break; |
| default: |
| SkASSERT(false); |
| } |
| } |
| |
| void SkColorSpaceXform_A2B::addMatrix(const SkMatrix44& matrix) { |
| fMatrices.push_front(std::vector<float>(12)); |
| auto& m = fMatrices.front(); |
| m[ 0] = matrix.get(0, 0); |
| m[ 1] = matrix.get(1, 0); |
| m[ 2] = matrix.get(2, 0); |
| m[ 3] = matrix.get(0, 1); |
| m[ 4] = matrix.get(1, 1); |
| m[ 5] = matrix.get(2, 1); |
| m[ 6] = matrix.get(0, 2); |
| m[ 7] = matrix.get(1, 2); |
| m[ 8] = matrix.get(2, 2); |
| m[ 9] = matrix.get(0, 3); |
| m[10] = matrix.get(1, 3); |
| m[11] = matrix.get(2, 3); |
| SkASSERT(matrix.get(3, 0) == 0.f); |
| SkASSERT(matrix.get(3, 1) == 0.f); |
| SkASSERT(matrix.get(3, 2) == 0.f); |
| SkASSERT(matrix.get(3, 3) == 1.f); |
| fElementsPipeline.append(SkRasterPipeline::matrix_3x4, m.data()); |
| fElementsPipeline.append(SkRasterPipeline::clamp_0); |
| fElementsPipeline.append(SkRasterPipeline::clamp_1); |
| } |