| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "include/utils/SkShadowUtils.h" |
| |
| #include "include/core/SkCanvas.h" |
| #include "include/core/SkColorFilter.h" |
| #include "include/core/SkMaskFilter.h" |
| #include "include/core/SkPath.h" |
| #include "include/core/SkString.h" |
| #include "include/core/SkVertices.h" |
| #include "include/private/SkColorData.h" |
| #include "include/private/SkIDChangeListener.h" |
| #include "include/private/SkTPin.h" |
| #include "include/utils/SkRandom.h" |
| #include "src/core/SkBlurMask.h" |
| #include "src/core/SkColorFilterBase.h" |
| #include "src/core/SkColorFilterPriv.h" |
| #include "src/core/SkDevice.h" |
| #include "src/core/SkDrawShadowInfo.h" |
| #include "src/core/SkEffectPriv.h" |
| #include "src/core/SkPathPriv.h" |
| #include "src/core/SkRasterPipeline.h" |
| #include "src/core/SkResourceCache.h" |
| #include "src/core/SkRuntimeEffectPriv.h" |
| #include "src/core/SkTLazy.h" |
| #include "src/core/SkVM.h" |
| #include "src/core/SkVerticesPriv.h" |
| #include "src/utils/SkShadowTessellator.h" |
| #include <new> |
| #if SK_SUPPORT_GPU |
| #include "src/gpu/effects/GrSkSLFP.h" |
| #include "src/gpu/geometry/GrStyledShape.h" |
| #endif |
| |
| /** |
| * Gaussian color filter -- produces a Gaussian ramp based on the color's B value, |
| * then blends with the color's G value. |
| * Final result is black with alpha of Gaussian(B)*G. |
| * The assumption is that the original color's alpha is 1. |
| */ |
| class SkGaussianColorFilter : public SkColorFilterBase { |
| public: |
| SkGaussianColorFilter() : INHERITED() {} |
| |
| #if SK_SUPPORT_GPU |
| GrFPResult asFragmentProcessor(std::unique_ptr<GrFragmentProcessor> inputFP, |
| GrRecordingContext*, const GrColorInfo&) const override; |
| #endif |
| |
| protected: |
| void flatten(SkWriteBuffer&) const override {} |
| bool onAppendStages(const SkStageRec& rec, bool shaderIsOpaque) const override { |
| rec.fPipeline->append(SkRasterPipeline::gauss_a_to_rgba); |
| return true; |
| } |
| |
| skvm::Color onProgram(skvm::Builder* p, skvm::Color c, const SkColorInfo& dst, skvm::Uniforms*, |
| SkArenaAlloc*) const override { |
| // x = 1 - x; |
| // exp(-x * x * 4) - 0.018f; |
| // ... now approximate with quartic |
| // |
| skvm::F32 x = p->splat(-2.26661229133605957031f); |
| x = c.a * x + 2.89795351028442382812f; |
| x = c.a * x + 0.21345567703247070312f; |
| x = c.a * x + 0.15489584207534790039f; |
| x = c.a * x + 0.00030726194381713867f; |
| return {x, x, x, x}; |
| } |
| |
| private: |
| SK_FLATTENABLE_HOOKS(SkGaussianColorFilter) |
| |
| using INHERITED = SkColorFilterBase; |
| }; |
| |
| sk_sp<SkFlattenable> SkGaussianColorFilter::CreateProc(SkReadBuffer&) { |
| return SkColorFilterPriv::MakeGaussian(); |
| } |
| |
| #if SK_SUPPORT_GPU |
| |
| GrFPResult SkGaussianColorFilter::asFragmentProcessor(std::unique_ptr<GrFragmentProcessor> inputFP, |
| GrRecordingContext*, |
| const GrColorInfo&) const { |
| static auto effect = SkMakeRuntimeEffect(SkRuntimeEffect::MakeForColorFilter, R"( |
| half4 main(half4 inColor) { |
| half factor = 1 - inColor.a; |
| factor = exp(-factor * factor * 4) - 0.018; |
| return half4(factor); |
| } |
| )"); |
| return GrFPSuccess(GrSkSLFP::Make(effect, "gaussian_fp", std::move(inputFP))); |
| } |
| #endif |
| |
| sk_sp<SkColorFilter> SkColorFilterPriv::MakeGaussian() { |
| return sk_sp<SkColorFilter>(new SkGaussianColorFilter); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| namespace { |
| |
| uint64_t resource_cache_shared_id() { |
| return 0x2020776f64616873llu; // 'shadow ' |
| } |
| |
| /** Factory for an ambient shadow mesh with particular shadow properties. */ |
| struct AmbientVerticesFactory { |
| SkScalar fOccluderHeight = SK_ScalarNaN; // NaN so that isCompatible will fail until init'ed. |
| bool fTransparent; |
| SkVector fOffset; |
| |
| bool isCompatible(const AmbientVerticesFactory& that, SkVector* translate) const { |
| if (fOccluderHeight != that.fOccluderHeight || fTransparent != that.fTransparent) { |
| return false; |
| } |
| *translate = that.fOffset; |
| return true; |
| } |
| |
| sk_sp<SkVertices> makeVertices(const SkPath& path, const SkMatrix& ctm, |
| SkVector* translate) const { |
| SkPoint3 zParams = SkPoint3::Make(0, 0, fOccluderHeight); |
| // pick a canonical place to generate shadow |
| SkMatrix noTrans(ctm); |
| if (!ctm.hasPerspective()) { |
| noTrans[SkMatrix::kMTransX] = 0; |
| noTrans[SkMatrix::kMTransY] = 0; |
| } |
| *translate = fOffset; |
| return SkShadowTessellator::MakeAmbient(path, noTrans, zParams, fTransparent); |
| } |
| }; |
| |
| /** Factory for an spot shadow mesh with particular shadow properties. */ |
| struct SpotVerticesFactory { |
| enum class OccluderType { |
| // The umbra cannot be dropped out because either the occluder is not opaque, |
| // or the center of the umbra is visible. |
| kTransparent, |
| // The umbra can be dropped where it is occluded. |
| kOpaquePartialUmbra, |
| // It is known that the entire umbra is occluded. |
| kOpaqueNoUmbra, |
| // The light is directional |
| kDirectional |
| }; |
| |
| SkVector fOffset; |
| SkPoint fLocalCenter; |
| SkScalar fOccluderHeight = SK_ScalarNaN; // NaN so that isCompatible will fail until init'ed. |
| SkPoint3 fDevLightPos; |
| SkScalar fLightRadius; |
| OccluderType fOccluderType; |
| |
| bool isCompatible(const SpotVerticesFactory& that, SkVector* translate) const { |
| if (fOccluderHeight != that.fOccluderHeight || fDevLightPos.fZ != that.fDevLightPos.fZ || |
| fLightRadius != that.fLightRadius || fOccluderType != that.fOccluderType) { |
| return false; |
| } |
| switch (fOccluderType) { |
| case OccluderType::kTransparent: |
| case OccluderType::kOpaqueNoUmbra: |
| // 'this' and 'that' will either both have no umbra removed or both have all the |
| // umbra removed. |
| *translate = that.fOffset; |
| return true; |
| case OccluderType::kOpaquePartialUmbra: |
| // In this case we partially remove the umbra differently for 'this' and 'that' |
| // if the offsets don't match. |
| if (fOffset == that.fOffset) { |
| translate->set(0, 0); |
| return true; |
| } |
| return false; |
| case OccluderType::kDirectional: |
| *translate = that.fOffset - fOffset; |
| return true; |
| } |
| SK_ABORT("Uninitialized occluder type?"); |
| } |
| |
| sk_sp<SkVertices> makeVertices(const SkPath& path, const SkMatrix& ctm, |
| SkVector* translate) const { |
| bool transparent = OccluderType::kTransparent == fOccluderType; |
| bool directional = OccluderType::kDirectional == fOccluderType; |
| SkPoint3 zParams = SkPoint3::Make(0, 0, fOccluderHeight); |
| if (directional) { |
| translate->set(0, 0); |
| return SkShadowTessellator::MakeSpot(path, ctm, zParams, fDevLightPos, fLightRadius, |
| transparent, true); |
| } else if (ctm.hasPerspective() || OccluderType::kOpaquePartialUmbra == fOccluderType) { |
| translate->set(0, 0); |
| return SkShadowTessellator::MakeSpot(path, ctm, zParams, fDevLightPos, fLightRadius, |
| transparent, false); |
| } else { |
| // pick a canonical place to generate shadow, with light centered over path |
| SkMatrix noTrans(ctm); |
| noTrans[SkMatrix::kMTransX] = 0; |
| noTrans[SkMatrix::kMTransY] = 0; |
| SkPoint devCenter(fLocalCenter); |
| noTrans.mapPoints(&devCenter, 1); |
| SkPoint3 centerLightPos = SkPoint3::Make(devCenter.fX, devCenter.fY, fDevLightPos.fZ); |
| *translate = fOffset; |
| return SkShadowTessellator::MakeSpot(path, noTrans, zParams, |
| centerLightPos, fLightRadius, transparent, false); |
| } |
| } |
| }; |
| |
| /** |
| * This manages a set of tessellations for a given shape in the cache. Because SkResourceCache |
| * records are immutable this is not itself a Rec. When we need to update it we return this on |
| * the FindVisitor and let the cache destroy the Rec. We'll update the tessellations and then add |
| * a new Rec with an adjusted size for any deletions/additions. |
| */ |
| class CachedTessellations : public SkRefCnt { |
| public: |
| size_t size() const { return fAmbientSet.size() + fSpotSet.size(); } |
| |
| sk_sp<SkVertices> find(const AmbientVerticesFactory& ambient, const SkMatrix& matrix, |
| SkVector* translate) const { |
| return fAmbientSet.find(ambient, matrix, translate); |
| } |
| |
| sk_sp<SkVertices> add(const SkPath& devPath, const AmbientVerticesFactory& ambient, |
| const SkMatrix& matrix, SkVector* translate) { |
| return fAmbientSet.add(devPath, ambient, matrix, translate); |
| } |
| |
| sk_sp<SkVertices> find(const SpotVerticesFactory& spot, const SkMatrix& matrix, |
| SkVector* translate) const { |
| return fSpotSet.find(spot, matrix, translate); |
| } |
| |
| sk_sp<SkVertices> add(const SkPath& devPath, const SpotVerticesFactory& spot, |
| const SkMatrix& matrix, SkVector* translate) { |
| return fSpotSet.add(devPath, spot, matrix, translate); |
| } |
| |
| private: |
| template <typename FACTORY, int MAX_ENTRIES> |
| class Set { |
| public: |
| size_t size() const { return fSize; } |
| |
| sk_sp<SkVertices> find(const FACTORY& factory, const SkMatrix& matrix, |
| SkVector* translate) const { |
| for (int i = 0; i < MAX_ENTRIES; ++i) { |
| if (fEntries[i].fFactory.isCompatible(factory, translate)) { |
| const SkMatrix& m = fEntries[i].fMatrix; |
| if (matrix.hasPerspective() || m.hasPerspective()) { |
| if (matrix != fEntries[i].fMatrix) { |
| continue; |
| } |
| } else if (matrix.getScaleX() != m.getScaleX() || |
| matrix.getSkewX() != m.getSkewX() || |
| matrix.getScaleY() != m.getScaleY() || |
| matrix.getSkewY() != m.getSkewY()) { |
| continue; |
| } |
| return fEntries[i].fVertices; |
| } |
| } |
| return nullptr; |
| } |
| |
| sk_sp<SkVertices> add(const SkPath& path, const FACTORY& factory, const SkMatrix& matrix, |
| SkVector* translate) { |
| sk_sp<SkVertices> vertices = factory.makeVertices(path, matrix, translate); |
| if (!vertices) { |
| return nullptr; |
| } |
| int i; |
| if (fCount < MAX_ENTRIES) { |
| i = fCount++; |
| } else { |
| i = fRandom.nextULessThan(MAX_ENTRIES); |
| fSize -= fEntries[i].fVertices->approximateSize(); |
| } |
| fEntries[i].fFactory = factory; |
| fEntries[i].fVertices = vertices; |
| fEntries[i].fMatrix = matrix; |
| fSize += vertices->approximateSize(); |
| return vertices; |
| } |
| |
| private: |
| struct Entry { |
| FACTORY fFactory; |
| sk_sp<SkVertices> fVertices; |
| SkMatrix fMatrix; |
| }; |
| Entry fEntries[MAX_ENTRIES]; |
| int fCount = 0; |
| size_t fSize = 0; |
| SkRandom fRandom; |
| }; |
| |
| Set<AmbientVerticesFactory, 4> fAmbientSet; |
| Set<SpotVerticesFactory, 4> fSpotSet; |
| }; |
| |
| /** |
| * A record of shadow vertices stored in SkResourceCache of CachedTessellations for a particular |
| * path. The key represents the path's geometry and not any shadow params. |
| */ |
| class CachedTessellationsRec : public SkResourceCache::Rec { |
| public: |
| CachedTessellationsRec(const SkResourceCache::Key& key, |
| sk_sp<CachedTessellations> tessellations) |
| : fTessellations(std::move(tessellations)) { |
| fKey.reset(new uint8_t[key.size()]); |
| memcpy(fKey.get(), &key, key.size()); |
| } |
| |
| const Key& getKey() const override { |
| return *reinterpret_cast<SkResourceCache::Key*>(fKey.get()); |
| } |
| |
| size_t bytesUsed() const override { return fTessellations->size(); } |
| |
| const char* getCategory() const override { return "tessellated shadow masks"; } |
| |
| sk_sp<CachedTessellations> refTessellations() const { return fTessellations; } |
| |
| template <typename FACTORY> |
| sk_sp<SkVertices> find(const FACTORY& factory, const SkMatrix& matrix, |
| SkVector* translate) const { |
| return fTessellations->find(factory, matrix, translate); |
| } |
| |
| private: |
| std::unique_ptr<uint8_t[]> fKey; |
| sk_sp<CachedTessellations> fTessellations; |
| }; |
| |
| /** |
| * Used by FindVisitor to determine whether a cache entry can be reused and if so returns the |
| * vertices and a translation vector. If the CachedTessellations does not contain a suitable |
| * mesh then we inform SkResourceCache to destroy the Rec and we return the CachedTessellations |
| * to the caller. The caller will update it and reinsert it back into the cache. |
| */ |
| template <typename FACTORY> |
| struct FindContext { |
| FindContext(const SkMatrix* viewMatrix, const FACTORY* factory) |
| : fViewMatrix(viewMatrix), fFactory(factory) {} |
| const SkMatrix* const fViewMatrix; |
| // If this is valid after Find is called then we found the vertices and they should be drawn |
| // with fTranslate applied. |
| sk_sp<SkVertices> fVertices; |
| SkVector fTranslate = {0, 0}; |
| |
| // If this is valid after Find then the caller should add the vertices to the tessellation set |
| // and create a new CachedTessellationsRec and insert it into SkResourceCache. |
| sk_sp<CachedTessellations> fTessellationsOnFailure; |
| |
| const FACTORY* fFactory; |
| }; |
| |
| /** |
| * Function called by SkResourceCache when a matching cache key is found. The FACTORY and matrix of |
| * the FindContext are used to determine if the vertices are reusable. If so the vertices and |
| * necessary translation vector are set on the FindContext. |
| */ |
| template <typename FACTORY> |
| bool FindVisitor(const SkResourceCache::Rec& baseRec, void* ctx) { |
| FindContext<FACTORY>* findContext = (FindContext<FACTORY>*)ctx; |
| const CachedTessellationsRec& rec = static_cast<const CachedTessellationsRec&>(baseRec); |
| findContext->fVertices = |
| rec.find(*findContext->fFactory, *findContext->fViewMatrix, &findContext->fTranslate); |
| if (findContext->fVertices) { |
| return true; |
| } |
| // We ref the tessellations and let the cache destroy the Rec. Once the tessellations have been |
| // manipulated we will add a new Rec. |
| findContext->fTessellationsOnFailure = rec.refTessellations(); |
| return false; |
| } |
| |
| class ShadowedPath { |
| public: |
| ShadowedPath(const SkPath* path, const SkMatrix* viewMatrix) |
| : fPath(path) |
| , fViewMatrix(viewMatrix) |
| #if SK_SUPPORT_GPU |
| , fShapeForKey(*path, GrStyle::SimpleFill()) |
| #endif |
| {} |
| |
| const SkPath& path() const { return *fPath; } |
| const SkMatrix& viewMatrix() const { return *fViewMatrix; } |
| #if SK_SUPPORT_GPU |
| /** Negative means the vertices should not be cached for this path. */ |
| int keyBytes() const { return fShapeForKey.unstyledKeySize() * sizeof(uint32_t); } |
| void writeKey(void* key) const { |
| fShapeForKey.writeUnstyledKey(reinterpret_cast<uint32_t*>(key)); |
| } |
| bool isRRect(SkRRect* rrect) { return fShapeForKey.asRRect(rrect, nullptr, nullptr, nullptr); } |
| #else |
| int keyBytes() const { return -1; } |
| void writeKey(void* key) const { SK_ABORT("Should never be called"); } |
| bool isRRect(SkRRect* rrect) { return false; } |
| #endif |
| |
| private: |
| const SkPath* fPath; |
| const SkMatrix* fViewMatrix; |
| #if SK_SUPPORT_GPU |
| GrStyledShape fShapeForKey; |
| #endif |
| }; |
| |
| // This creates a domain of keys in SkResourceCache used by this file. |
| static void* kNamespace; |
| |
| // When the SkPathRef genID changes, invalidate a corresponding GrResource described by key. |
| class ShadowInvalidator : public SkIDChangeListener { |
| public: |
| ShadowInvalidator(const SkResourceCache::Key& key) { |
| fKey.reset(new uint8_t[key.size()]); |
| memcpy(fKey.get(), &key, key.size()); |
| } |
| |
| private: |
| const SkResourceCache::Key& getKey() const { |
| return *reinterpret_cast<SkResourceCache::Key*>(fKey.get()); |
| } |
| |
| // always purge |
| static bool FindVisitor(const SkResourceCache::Rec&, void*) { |
| return false; |
| } |
| |
| void changed() override { |
| SkResourceCache::Find(this->getKey(), ShadowInvalidator::FindVisitor, nullptr); |
| } |
| |
| std::unique_ptr<uint8_t[]> fKey; |
| }; |
| |
| /** |
| * Draws a shadow to 'canvas'. The vertices used to draw the shadow are created by 'factory' unless |
| * they are first found in SkResourceCache. |
| */ |
| template <typename FACTORY> |
| bool draw_shadow(const FACTORY& factory, |
| std::function<void(const SkVertices*, SkBlendMode, const SkPaint&, |
| SkScalar tx, SkScalar ty, bool)> drawProc, ShadowedPath& path, SkColor color) { |
| FindContext<FACTORY> context(&path.viewMatrix(), &factory); |
| |
| SkResourceCache::Key* key = nullptr; |
| SkAutoSTArray<32 * 4, uint8_t> keyStorage; |
| int keyDataBytes = path.keyBytes(); |
| if (keyDataBytes >= 0) { |
| keyStorage.reset(keyDataBytes + sizeof(SkResourceCache::Key)); |
| key = new (keyStorage.begin()) SkResourceCache::Key(); |
| path.writeKey((uint32_t*)(keyStorage.begin() + sizeof(*key))); |
| key->init(&kNamespace, resource_cache_shared_id(), keyDataBytes); |
| SkResourceCache::Find(*key, FindVisitor<FACTORY>, &context); |
| } |
| |
| sk_sp<SkVertices> vertices; |
| bool foundInCache = SkToBool(context.fVertices); |
| if (foundInCache) { |
| vertices = std::move(context.fVertices); |
| } else { |
| // TODO: handle transforming the path as part of the tessellator |
| if (key) { |
| // Update or initialize a tessellation set and add it to the cache. |
| sk_sp<CachedTessellations> tessellations; |
| if (context.fTessellationsOnFailure) { |
| tessellations = std::move(context.fTessellationsOnFailure); |
| } else { |
| tessellations.reset(new CachedTessellations()); |
| } |
| vertices = tessellations->add(path.path(), factory, path.viewMatrix(), |
| &context.fTranslate); |
| if (!vertices) { |
| return false; |
| } |
| auto rec = new CachedTessellationsRec(*key, std::move(tessellations)); |
| SkPathPriv::AddGenIDChangeListener(path.path(), sk_make_sp<ShadowInvalidator>(*key)); |
| SkResourceCache::Add(rec); |
| } else { |
| vertices = factory.makeVertices(path.path(), path.viewMatrix(), |
| &context.fTranslate); |
| if (!vertices) { |
| return false; |
| } |
| } |
| } |
| |
| SkPaint paint; |
| // Run the vertex color through a GaussianColorFilter and then modulate the grayscale result of |
| // that against our 'color' param. |
| paint.setColorFilter( |
| SkColorFilters::Blend(color, SkBlendMode::kModulate)->makeComposed( |
| SkColorFilterPriv::MakeGaussian())); |
| |
| drawProc(vertices.get(), SkBlendMode::kModulate, paint, |
| context.fTranslate.fX, context.fTranslate.fY, path.viewMatrix().hasPerspective()); |
| |
| return true; |
| } |
| } // namespace |
| |
| static bool tilted(const SkPoint3& zPlaneParams) { |
| return !SkScalarNearlyZero(zPlaneParams.fX) || !SkScalarNearlyZero(zPlaneParams.fY); |
| } |
| |
| void SkShadowUtils::ComputeTonalColors(SkColor inAmbientColor, SkColor inSpotColor, |
| SkColor* outAmbientColor, SkColor* outSpotColor) { |
| // For tonal color we only compute color values for the spot shadow. |
| // The ambient shadow is greyscale only. |
| |
| // Ambient |
| *outAmbientColor = SkColorSetARGB(SkColorGetA(inAmbientColor), 0, 0, 0); |
| |
| // Spot |
| int spotR = SkColorGetR(inSpotColor); |
| int spotG = SkColorGetG(inSpotColor); |
| int spotB = SkColorGetB(inSpotColor); |
| int max = std::max(std::max(spotR, spotG), spotB); |
| int min = std::min(std::min(spotR, spotG), spotB); |
| SkScalar luminance = 0.5f*(max + min)/255.f; |
| SkScalar origA = SkColorGetA(inSpotColor)/255.f; |
| |
| // We compute a color alpha value based on the luminance of the color, scaled by an |
| // adjusted alpha value. We want the following properties to match the UX examples |
| // (assuming a = 0.25) and to ensure that we have reasonable results when the color |
| // is black and/or the alpha is 0: |
| // f(0, a) = 0 |
| // f(luminance, 0) = 0 |
| // f(1, 0.25) = .5 |
| // f(0.5, 0.25) = .4 |
| // f(1, 1) = 1 |
| // The following functions match this as closely as possible. |
| SkScalar alphaAdjust = (2.6f + (-2.66667f + 1.06667f*origA)*origA)*origA; |
| SkScalar colorAlpha = (3.544762f + (-4.891428f + 2.3466f*luminance)*luminance)*luminance; |
| colorAlpha = SkTPin(alphaAdjust*colorAlpha, 0.0f, 1.0f); |
| |
| // Similarly, we set the greyscale alpha based on luminance and alpha so that |
| // f(0, a) = a |
| // f(luminance, 0) = 0 |
| // f(1, 0.25) = 0.15 |
| SkScalar greyscaleAlpha = SkTPin(origA*(1 - 0.4f*luminance), 0.0f, 1.0f); |
| |
| // The final color we want to emulate is generated by rendering a color shadow (C_rgb) using an |
| // alpha computed from the color's luminance (C_a), and then a black shadow with alpha (S_a) |
| // which is an adjusted value of 'a'. Assuming SrcOver, a background color of B_rgb, and |
| // ignoring edge falloff, this becomes |
| // |
| // (C_a - S_a*C_a)*C_rgb + (1 - (S_a + C_a - S_a*C_a))*B_rgb |
| // |
| // Assuming premultiplied alpha, this means we scale the color by (C_a - S_a*C_a) and |
| // set the alpha to (S_a + C_a - S_a*C_a). |
| SkScalar colorScale = colorAlpha*(SK_Scalar1 - greyscaleAlpha); |
| SkScalar tonalAlpha = colorScale + greyscaleAlpha; |
| SkScalar unPremulScale = colorScale / tonalAlpha; |
| *outSpotColor = SkColorSetARGB(tonalAlpha*255.999f, |
| unPremulScale*spotR, |
| unPremulScale*spotG, |
| unPremulScale*spotB); |
| } |
| |
| static bool fill_shadow_rec(const SkPath& path, const SkPoint3& zPlaneParams, |
| const SkPoint3& lightPos, SkScalar lightRadius, |
| SkColor ambientColor, SkColor spotColor, |
| uint32_t flags, const SkMatrix& ctm, SkDrawShadowRec* rec) { |
| SkPoint pt = { lightPos.fX, lightPos.fY }; |
| if (!SkToBool(flags & kDirectionalLight_ShadowFlag)) { |
| // If light position is in device space, need to transform to local space |
| // before applying to SkCanvas. |
| SkMatrix inverse; |
| if (!ctm.invert(&inverse)) { |
| return false; |
| } |
| inverse.mapPoints(&pt, 1); |
| } |
| |
| rec->fZPlaneParams = zPlaneParams; |
| rec->fLightPos = { pt.fX, pt.fY, lightPos.fZ }; |
| rec->fLightRadius = lightRadius; |
| rec->fAmbientColor = ambientColor; |
| rec->fSpotColor = spotColor; |
| rec->fFlags = flags; |
| |
| return true; |
| } |
| |
| // Draw an offset spot shadow and outlining ambient shadow for the given path. |
| void SkShadowUtils::DrawShadow(SkCanvas* canvas, const SkPath& path, const SkPoint3& zPlaneParams, |
| const SkPoint3& lightPos, SkScalar lightRadius, |
| SkColor ambientColor, SkColor spotColor, |
| uint32_t flags) { |
| SkDrawShadowRec rec; |
| if (!fill_shadow_rec(path, zPlaneParams, lightPos, lightRadius, ambientColor, spotColor, |
| flags, canvas->getTotalMatrix(), &rec)) { |
| return; |
| } |
| |
| canvas->private_draw_shadow_rec(path, rec); |
| } |
| |
| bool SkShadowUtils::GetLocalBounds(const SkMatrix& ctm, const SkPath& path, |
| const SkPoint3& zPlaneParams, const SkPoint3& lightPos, |
| SkScalar lightRadius, uint32_t flags, SkRect* bounds) { |
| SkDrawShadowRec rec; |
| if (!fill_shadow_rec(path, zPlaneParams, lightPos, lightRadius, SK_ColorBLACK, SK_ColorBLACK, |
| flags, ctm, &rec)) { |
| return false; |
| } |
| |
| SkDrawShadowMetrics::GetLocalBounds(path, rec, ctm, bounds); |
| |
| return true; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| static bool validate_rec(const SkDrawShadowRec& rec) { |
| return rec.fLightPos.isFinite() && rec.fZPlaneParams.isFinite() && |
| SkScalarIsFinite(rec.fLightRadius); |
| } |
| |
| void SkBaseDevice::drawShadow(const SkPath& path, const SkDrawShadowRec& rec) { |
| auto drawVertsProc = [this](const SkVertices* vertices, SkBlendMode mode, const SkPaint& paint, |
| SkScalar tx, SkScalar ty, bool hasPerspective) { |
| if (vertices->priv().vertexCount()) { |
| // For perspective shadows we've already computed the shadow in world space, |
| // and we can't translate it without changing it. Otherwise we concat the |
| // change in translation from the cached version. |
| SkAutoDeviceTransformRestore adr( |
| this, |
| hasPerspective ? SkMatrix::I() |
| : this->localToDevice() * SkMatrix::Translate(tx, ty)); |
| this->drawVertices(vertices, mode, paint); |
| } |
| }; |
| |
| if (!validate_rec(rec)) { |
| return; |
| } |
| |
| SkMatrix viewMatrix = this->localToDevice(); |
| SkAutoDeviceTransformRestore adr(this, SkMatrix::I()); |
| |
| ShadowedPath shadowedPath(&path, &viewMatrix); |
| |
| bool tiltZPlane = tilted(rec.fZPlaneParams); |
| bool transparent = SkToBool(rec.fFlags & SkShadowFlags::kTransparentOccluder_ShadowFlag); |
| bool directional = SkToBool(rec.fFlags & kDirectionalLight_ShadowFlag); |
| bool uncached = tiltZPlane || path.isVolatile(); |
| |
| SkPoint3 zPlaneParams = rec.fZPlaneParams; |
| SkPoint3 devLightPos = rec.fLightPos; |
| if (directional) { |
| devLightPos.normalize(); |
| } else { |
| viewMatrix.mapPoints((SkPoint*)&devLightPos.fX, 1); |
| } |
| float lightRadius = rec.fLightRadius; |
| |
| if (SkColorGetA(rec.fAmbientColor) > 0) { |
| bool success = false; |
| if (uncached) { |
| sk_sp<SkVertices> vertices = SkShadowTessellator::MakeAmbient(path, viewMatrix, |
| zPlaneParams, |
| transparent); |
| if (vertices) { |
| SkPaint paint; |
| // Run the vertex color through a GaussianColorFilter and then modulate the |
| // grayscale result of that against our 'color' param. |
| paint.setColorFilter( |
| SkColorFilters::Blend(rec.fAmbientColor, |
| SkBlendMode::kModulate)->makeComposed( |
| SkColorFilterPriv::MakeGaussian())); |
| this->drawVertices(vertices.get(), SkBlendMode::kModulate, paint); |
| success = true; |
| } |
| } |
| |
| if (!success) { |
| AmbientVerticesFactory factory; |
| factory.fOccluderHeight = zPlaneParams.fZ; |
| factory.fTransparent = transparent; |
| if (viewMatrix.hasPerspective()) { |
| factory.fOffset.set(0, 0); |
| } else { |
| factory.fOffset.fX = viewMatrix.getTranslateX(); |
| factory.fOffset.fY = viewMatrix.getTranslateY(); |
| } |
| |
| if (!draw_shadow(factory, drawVertsProc, shadowedPath, rec.fAmbientColor)) { |
| // Pretransform the path to avoid transforming the stroke, below. |
| SkPath devSpacePath; |
| path.transform(viewMatrix, &devSpacePath); |
| devSpacePath.setIsVolatile(true); |
| |
| // The tesselator outsets by AmbientBlurRadius (or 'r') to get the outer ring of |
| // the tesselation, and sets the alpha on the path to 1/AmbientRecipAlpha (or 'a'). |
| // |
| // We want to emulate this with a blur. The full blur width (2*blurRadius or 'f') |
| // can be calculated by interpolating: |
| // |
| // original edge outer edge |
| // | |<---------- r ------>| |
| // |<------|--- f -------------->| |
| // | | | |
| // alpha = 1 alpha = a alpha = 0 |
| // |
| // Taking ratios, f/1 = r/a, so f = r/a and blurRadius = f/2. |
| // |
| // We now need to outset the path to place the new edge in the center of the |
| // blur region: |
| // |
| // original new |
| // | |<------|--- r ------>| |
| // |<------|--- f -|------------>| |
| // | |<- o ->|<--- f/2 --->| |
| // |
| // r = o + f/2, so o = r - f/2 |
| // |
| // We outset by using the stroker, so the strokeWidth is o/2. |
| // |
| SkScalar devSpaceOutset = SkDrawShadowMetrics::AmbientBlurRadius(zPlaneParams.fZ); |
| SkScalar oneOverA = SkDrawShadowMetrics::AmbientRecipAlpha(zPlaneParams.fZ); |
| SkScalar blurRadius = 0.5f*devSpaceOutset*oneOverA; |
| SkScalar strokeWidth = 0.5f*(devSpaceOutset - blurRadius); |
| |
| // Now draw with blur |
| SkPaint paint; |
| paint.setColor(rec.fAmbientColor); |
| paint.setStrokeWidth(strokeWidth); |
| paint.setStyle(SkPaint::kStrokeAndFill_Style); |
| SkScalar sigma = SkBlurMask::ConvertRadiusToSigma(blurRadius); |
| bool respectCTM = false; |
| paint.setMaskFilter(SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, sigma, respectCTM)); |
| this->drawPath(devSpacePath, paint); |
| } |
| } |
| } |
| |
| if (SkColorGetA(rec.fSpotColor) > 0) { |
| bool success = false; |
| if (uncached) { |
| sk_sp<SkVertices> vertices = SkShadowTessellator::MakeSpot(path, viewMatrix, |
| zPlaneParams, |
| devLightPos, lightRadius, |
| transparent, |
| directional); |
| if (vertices) { |
| SkPaint paint; |
| // Run the vertex color through a GaussianColorFilter and then modulate the |
| // grayscale result of that against our 'color' param. |
| paint.setColorFilter( |
| SkColorFilters::Blend(rec.fSpotColor, |
| SkBlendMode::kModulate)->makeComposed( |
| SkColorFilterPriv::MakeGaussian())); |
| this->drawVertices(vertices.get(), SkBlendMode::kModulate, paint); |
| success = true; |
| } |
| } |
| |
| if (!success) { |
| SpotVerticesFactory factory; |
| factory.fOccluderHeight = zPlaneParams.fZ; |
| factory.fDevLightPos = devLightPos; |
| factory.fLightRadius = lightRadius; |
| |
| SkPoint center = SkPoint::Make(path.getBounds().centerX(), path.getBounds().centerY()); |
| factory.fLocalCenter = center; |
| viewMatrix.mapPoints(¢er, 1); |
| SkScalar radius, scale; |
| if (SkToBool(rec.fFlags & kDirectionalLight_ShadowFlag)) { |
| SkDrawShadowMetrics::GetDirectionalParams(zPlaneParams.fZ, devLightPos.fX, |
| devLightPos.fY, devLightPos.fZ, |
| lightRadius, &radius, &scale, |
| &factory.fOffset); |
| } else { |
| SkDrawShadowMetrics::GetSpotParams(zPlaneParams.fZ, devLightPos.fX - center.fX, |
| devLightPos.fY - center.fY, devLightPos.fZ, |
| lightRadius, &radius, &scale, &factory.fOffset); |
| } |
| |
| SkRect devBounds; |
| viewMatrix.mapRect(&devBounds, path.getBounds()); |
| if (directional) { |
| factory.fOccluderType = SpotVerticesFactory::OccluderType::kDirectional; |
| } else if (transparent || |
| SkTAbs(factory.fOffset.fX) > 0.5f*devBounds.width() || |
| SkTAbs(factory.fOffset.fY) > 0.5f*devBounds.height()) { |
| // if the translation of the shadow is big enough we're going to end up |
| // filling the entire umbra, so we can treat these as all the same |
| factory.fOccluderType = SpotVerticesFactory::OccluderType::kTransparent; |
| } else if (factory.fOffset.length()*scale + scale < radius) { |
| // if we don't translate more than the blur distance, can assume umbra is covered |
| factory.fOccluderType = SpotVerticesFactory::OccluderType::kOpaqueNoUmbra; |
| } else if (path.isConvex()) { |
| factory.fOccluderType = SpotVerticesFactory::OccluderType::kOpaquePartialUmbra; |
| } else { |
| factory.fOccluderType = SpotVerticesFactory::OccluderType::kTransparent; |
| } |
| // need to add this after we classify the shadow |
| factory.fOffset.fX += viewMatrix.getTranslateX(); |
| factory.fOffset.fY += viewMatrix.getTranslateY(); |
| |
| SkColor color = rec.fSpotColor; |
| #ifdef DEBUG_SHADOW_CHECKS |
| switch (factory.fOccluderType) { |
| case SpotVerticesFactory::OccluderType::kTransparent: |
| color = 0xFFD2B48C; // tan for transparent |
| break; |
| case SpotVerticesFactory::OccluderType::kOpaquePartialUmbra: |
| color = 0xFFFFA500; // orange for opaque |
| break; |
| case SpotVerticesFactory::OccluderType::kOpaqueNoUmbra: |
| color = 0xFFE5E500; // corn yellow for covered |
| break; |
| case SpotVerticesFactory::OccluderType::kDirectional: |
| color = 0xFF550000; // dark red for directional |
| break; |
| } |
| #endif |
| if (!draw_shadow(factory, drawVertsProc, shadowedPath, color)) { |
| // draw with blur |
| SkMatrix shadowMatrix; |
| if (!SkDrawShadowMetrics::GetSpotShadowTransform(devLightPos, lightRadius, |
| viewMatrix, zPlaneParams, |
| path.getBounds(), directional, |
| &shadowMatrix, &radius)) { |
| return; |
| } |
| SkAutoDeviceTransformRestore adr(this, shadowMatrix); |
| |
| SkPaint paint; |
| paint.setColor(rec.fSpotColor); |
| SkScalar sigma = SkBlurMask::ConvertRadiusToSigma(radius); |
| bool respectCTM = false; |
| paint.setMaskFilter(SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, sigma, respectCTM)); |
| this->drawPath(path, paint); |
| } |
| } |
| } |
| } |