| /* | |
| * Copyright 2014 Google Inc. | |
| * | |
| * Use of this source code is governed by a BSD-style license that can be | |
| * found in the LICENSE file. | |
| */ | |
| #include "src/core/SkMatrixPriv.h" | |
| #include "src/gpu/effects/GrBicubicEffect.h" | |
| #include "include/gpu/GrTexture.h" | |
| #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h" | |
| #include "src/gpu/glsl/GrGLSLProgramDataManager.h" | |
| #include "src/gpu/glsl/GrGLSLUniformHandler.h" | |
| class GrGLBicubicEffect : public GrGLSLFragmentProcessor { | |
| public: | |
| void emitCode(EmitArgs&) override; | |
| static inline void GenKey(const GrProcessor& effect, const GrShaderCaps&, | |
| GrProcessorKeyBuilder* b) { | |
| const GrBicubicEffect& bicubicEffect = effect.cast<GrBicubicEffect>(); | |
| b->add32(GrTextureDomain::GLDomain::DomainKey(bicubicEffect.domain())); | |
| uint32_t bidir = bicubicEffect.direction() == GrBicubicEffect::Direction::kXY ? 1 : 0; | |
| b->add32(bidir | (bicubicEffect.alphaType() << 1)); | |
| } | |
| protected: | |
| void onSetData(const GrGLSLProgramDataManager&, const GrFragmentProcessor&) override; | |
| private: | |
| typedef GrGLSLProgramDataManager::UniformHandle UniformHandle; | |
| UniformHandle fDimensions; | |
| GrTextureDomain::GLDomain fDomain; | |
| typedef GrGLSLFragmentProcessor INHERITED; | |
| }; | |
| void GrGLBicubicEffect::emitCode(EmitArgs& args) { | |
| const GrBicubicEffect& bicubicEffect = args.fFp.cast<GrBicubicEffect>(); | |
| GrGLSLUniformHandler* uniformHandler = args.fUniformHandler; | |
| fDimensions = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf4_GrSLType, "Dimensions"); | |
| const char* dims = uniformHandler->getUniformCStr(fDimensions); | |
| GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder; | |
| SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0].fVaryingPoint); | |
| /* | |
| * Filter weights come from Don Mitchell & Arun Netravali's 'Reconstruction Filters in Computer | |
| * Graphics', ACM SIGGRAPH Computer Graphics 22, 4 (Aug. 1988). | |
| * ACM DL: http://dl.acm.org/citation.cfm?id=378514 | |
| * Free : http://www.cs.utexas.edu/users/fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf | |
| * | |
| * The authors define a family of cubic filters with two free parameters (B and C): | |
| * | |
| * { (12 - 9B - 6C)|x|^3 + (-18 + 12B + 6C)|x|^2 + (6 - 2B) if |x| < 1 | |
| * k(x) = 1/6 { (-B - 6C)|x|^3 + (6B + 30C)|x|^2 + (-12B - 48C)|x| + (8B + 24C) if 1 <= |x| < 2 | |
| * { 0 otherwise | |
| * | |
| * Various well-known cubic splines can be generated, and the authors select (1/3, 1/3) as their | |
| * favorite overall spline - this is now commonly known as the Mitchell filter, and is the | |
| * source of the specific weights below. | |
| * | |
| * This is GLSL, so the matrix is column-major (transposed from standard matrix notation). | |
| */ | |
| fragBuilder->codeAppend("half4x4 kMitchellCoefficients = half4x4(" | |
| " 1.0 / 18.0, 16.0 / 18.0, 1.0 / 18.0, 0.0 / 18.0," | |
| "-9.0 / 18.0, 0.0 / 18.0, 9.0 / 18.0, 0.0 / 18.0," | |
| "15.0 / 18.0, -36.0 / 18.0, 27.0 / 18.0, -6.0 / 18.0," | |
| "-7.0 / 18.0, 21.0 / 18.0, -21.0 / 18.0, 7.0 / 18.0);"); | |
| fragBuilder->codeAppendf("float2 coord = %s - %s.xy * float2(0.5);", coords2D.c_str(), dims); | |
| // We unnormalize the coord in order to determine our fractional offset (f) within the texel | |
| // We then snap coord to a texel center and renormalize. The snap prevents cases where the | |
| // starting coords are near a texel boundary and accumulations of dims would cause us to skip/ | |
| // double hit a texel. | |
| fragBuilder->codeAppendf("half2 f = half2(fract(coord * %s.zw));", dims); | |
| fragBuilder->codeAppendf("coord = coord + (half2(0.5) - f) * %s.xy;", dims); | |
| if (bicubicEffect.direction() == GrBicubicEffect::Direction::kXY) { | |
| fragBuilder->codeAppend( | |
| "half4 wx = kMitchellCoefficients * half4(1.0, f.x, f.x * f.x, f.x * f.x * f.x);"); | |
| fragBuilder->codeAppend( | |
| "half4 wy = kMitchellCoefficients * half4(1.0, f.y, f.y * f.y, f.y * f.y * f.y);"); | |
| fragBuilder->codeAppend("half4 rowColors[4];"); | |
| for (int y = 0; y < 4; ++y) { | |
| for (int x = 0; x < 4; ++x) { | |
| SkString coord; | |
| coord.printf("coord + %s.xy * float2(%d, %d)", dims, x - 1, y - 1); | |
| SkString sampleVar; | |
| sampleVar.printf("rowColors[%d]", x); | |
| fDomain.sampleTexture(fragBuilder, | |
| args.fUniformHandler, | |
| args.fShaderCaps, | |
| bicubicEffect.domain(), | |
| sampleVar.c_str(), | |
| coord, | |
| args.fTexSamplers[0]); | |
| } | |
| fragBuilder->codeAppendf( | |
| "half4 s%d = wx.x * rowColors[0] + wx.y * rowColors[1] + wx.z * rowColors[2] + " | |
| "wx.w * rowColors[3];", | |
| y); | |
| } | |
| fragBuilder->codeAppend( | |
| "half4 bicubicColor = wy.x * s0 + wy.y * s1 + wy.z * s2 + wy.w * s3;"); | |
| } else { | |
| // One of the dims.xy values will be zero. So v here selects the nonzero value of f. | |
| fragBuilder->codeAppend("half v = f.x + f.y;"); | |
| fragBuilder->codeAppend("half v2 = v * v;"); | |
| fragBuilder->codeAppend("half4 w = kMitchellCoefficients * half4(1.0, v, v2, v2 * v);"); | |
| fragBuilder->codeAppend("half4 c[4];"); | |
| for (int i = 0; i < 4; ++i) { | |
| SkString coord; | |
| coord.printf("coord + %s.xy * half(%d)", dims, i - 1); | |
| SkString samplerVar; | |
| samplerVar.printf("c[%d]", i); | |
| // With added complexity we could apply the domain once in X or Y depending on | |
| // direction rather than for each of the four lookups, but then we might not be | |
| // be able to share code for Direction::kX and ::kY. | |
| fDomain.sampleTexture(fragBuilder, | |
| args.fUniformHandler, | |
| args.fShaderCaps, | |
| bicubicEffect.domain(), | |
| samplerVar.c_str(), | |
| coord, | |
| args.fTexSamplers[0]); | |
| } | |
| fragBuilder->codeAppend( | |
| "half4 bicubicColor = c[0] * w.x + c[1] * w.y + c[2] * w.z + c[3] * w.w;"); | |
| } | |
| // Bicubic can send colors out of range, so clamp to get them back in (source) gamut. | |
| // The kind of clamp we have to do depends on the alpha type. | |
| if (kPremul_SkAlphaType == bicubicEffect.alphaType()) { | |
| fragBuilder->codeAppend("bicubicColor.a = saturate(bicubicColor.a);"); | |
| fragBuilder->codeAppend( | |
| "bicubicColor.rgb = max(half3(0.0), min(bicubicColor.rgb, bicubicColor.aaa));"); | |
| } else { | |
| fragBuilder->codeAppend("bicubicColor = saturate(bicubicColor);"); | |
| } | |
| fragBuilder->codeAppendf("%s = bicubicColor * %s;", args.fOutputColor, args.fInputColor); | |
| } | |
| void GrGLBicubicEffect::onSetData(const GrGLSLProgramDataManager& pdman, | |
| const GrFragmentProcessor& processor) { | |
| const GrBicubicEffect& bicubicEffect = processor.cast<GrBicubicEffect>(); | |
| const auto& view = processor.textureSampler(0).view(); | |
| SkISize textureDims = view.proxy()->backingStoreDimensions(); | |
| float dims[4] = {0, 0, 0, 0}; | |
| if (bicubicEffect.direction() != GrBicubicEffect::Direction::kY) { | |
| dims[0] = 1.0f / textureDims.width(); | |
| dims[2] = textureDims.width(); | |
| } | |
| if (bicubicEffect.direction() != GrBicubicEffect::Direction::kX) { | |
| dims[1] = 1.0f / textureDims.height(); | |
| dims[3] = textureDims.height(); | |
| } | |
| pdman.set4fv(fDimensions, 1, dims); | |
| fDomain.setData(pdman, bicubicEffect.domain(), view, | |
| processor.textureSampler(0).samplerState()); | |
| } | |
| GrBicubicEffect::GrBicubicEffect(sk_sp<GrSurfaceProxy> proxy, const SkMatrix& matrix, | |
| const SkRect& domain, const GrSamplerState::WrapMode wrapModes[2], | |
| GrTextureDomain::Mode modeX, GrTextureDomain::Mode modeY, | |
| Direction direction, SkAlphaType alphaType) | |
| : INHERITED{kGrBicubicEffect_ClassID, | |
| ModulateForSamplerOptFlags( | |
| alphaType, GrTextureDomain::IsDecalSampled(wrapModes, modeX, modeY))} | |
| , fCoordTransform(matrix, proxy.get()) | |
| , fDomain(proxy.get(), domain, modeX, modeY) | |
| , fTextureSampler(std::move(proxy), | |
| GrSamplerState(wrapModes, GrSamplerState::Filter::kNearest)) | |
| , fAlphaType(alphaType) | |
| , fDirection(direction) { | |
| this->addCoordTransform(&fCoordTransform); | |
| this->setTextureSamplerCnt(1); | |
| } | |
| GrBicubicEffect::GrBicubicEffect(const GrBicubicEffect& that) | |
| : INHERITED(kGrBicubicEffect_ClassID, that.optimizationFlags()) | |
| , fCoordTransform(that.fCoordTransform) | |
| , fDomain(that.fDomain) | |
| , fTextureSampler(that.fTextureSampler) | |
| , fAlphaType(that.fAlphaType) | |
| , fDirection(that.fDirection) { | |
| this->addCoordTransform(&fCoordTransform); | |
| this->setTextureSamplerCnt(1); | |
| } | |
| void GrBicubicEffect::onGetGLSLProcessorKey(const GrShaderCaps& caps, | |
| GrProcessorKeyBuilder* b) const { | |
| GrGLBicubicEffect::GenKey(*this, caps, b); | |
| } | |
| GrGLSLFragmentProcessor* GrBicubicEffect::onCreateGLSLInstance() const { | |
| return new GrGLBicubicEffect; | |
| } | |
| bool GrBicubicEffect::onIsEqual(const GrFragmentProcessor& sBase) const { | |
| const GrBicubicEffect& s = sBase.cast<GrBicubicEffect>(); | |
| return fDomain == s.fDomain && fDirection == s.fDirection && fAlphaType == s.fAlphaType; | |
| } | |
| GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrBicubicEffect); | |
| #if GR_TEST_UTILS | |
| std::unique_ptr<GrFragmentProcessor> GrBicubicEffect::TestCreate(GrProcessorTestData* d) { | |
| int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx | |
| : GrProcessorUnitTest::kAlphaTextureIdx; | |
| static const GrSamplerState::WrapMode kClampClamp[] = {GrSamplerState::WrapMode::kClamp, | |
| GrSamplerState::WrapMode::kClamp}; | |
| SkAlphaType alphaType = d->fRandom->nextBool() ? kPremul_SkAlphaType : kUnpremul_SkAlphaType; | |
| Direction direction = Direction::kX; | |
| switch (d->fRandom->nextULessThan(3)) { | |
| case 0: | |
| direction = Direction::kX; | |
| break; | |
| case 1: | |
| direction = Direction::kY; | |
| break; | |
| case 2: | |
| direction = Direction::kXY; | |
| break; | |
| } | |
| return GrBicubicEffect::Make(d->textureProxy(texIdx), SkMatrix::I(), kClampClamp, direction, | |
| alphaType); | |
| } | |
| #endif | |
| ////////////////////////////////////////////////////////////////////////////// | |
| bool GrBicubicEffect::ShouldUseBicubic(const SkMatrix& matrix, GrSamplerState::Filter* filterMode) { | |
| switch (SkMatrixPriv::AdjustHighQualityFilterLevel(matrix)) { | |
| case kNone_SkFilterQuality: | |
| *filterMode = GrSamplerState::Filter::kNearest; | |
| break; | |
| case kLow_SkFilterQuality: | |
| *filterMode = GrSamplerState::Filter::kBilerp; | |
| break; | |
| case kMedium_SkFilterQuality: | |
| *filterMode = GrSamplerState::Filter::kMipMap; | |
| break; | |
| case kHigh_SkFilterQuality: | |
| // When we use the bicubic filtering effect each sample is read from the texture using | |
| // nearest neighbor sampling. | |
| *filterMode = GrSamplerState::Filter::kNearest; | |
| return true; | |
| } | |
| return false; | |
| } |