| /* |
| * 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 "SkShadowUtils.h" |
| #include "SkCanvas.h" |
| #include "SkColorFilter.h" |
| #include "SkColorPriv.h" |
| #include "SkDevice.h" |
| #include "SkDrawShadowRec.h" |
| #include "SkPath.h" |
| #include "SkPM4f.h" |
| #include "SkRandom.h" |
| #include "SkRasterPipeline.h" |
| #include "SkResourceCache.h" |
| #include "SkShadowTessellator.h" |
| #include "SkString.h" |
| #include "SkTLazy.h" |
| #include "SkVertices.h" |
| #if SK_SUPPORT_GPU |
| #include "GrShape.h" |
| #include "effects/GrBlurredEdgeFragmentProcessor.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 SK_API SkGaussianColorFilter : public SkColorFilter { |
| public: |
| static sk_sp<SkColorFilter> Make() { |
| return sk_sp<SkColorFilter>(new SkGaussianColorFilter); |
| } |
| |
| void filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const override; |
| void filterSpan4f(const SkPM4f src[], int count, SkPM4f result[]) const override; |
| |
| #if SK_SUPPORT_GPU |
| sk_sp<GrFragmentProcessor> asFragmentProcessor(GrContext*, SkColorSpace*) const override; |
| #endif |
| |
| SK_TO_STRING_OVERRIDE() |
| SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkGaussianColorFilter) |
| |
| protected: |
| void flatten(SkWriteBuffer&) const override {} |
| void onAppendStages(SkRasterPipeline* pipeline, SkColorSpace* dstCS, SkArenaAlloc* alloc, |
| bool shaderIsOpaque) const override { |
| pipeline->append(SkRasterPipeline::gauss_a_to_rgba); |
| } |
| private: |
| SkGaussianColorFilter() : INHERITED() {} |
| |
| typedef SkColorFilter INHERITED; |
| }; |
| |
| static inline float eval_gaussian(float x) { |
| // x = 1 - x; |
| // return sk_float_exp(-x * x * 4) - 0.018f; |
| |
| return 0.00030726194381713867f + |
| x*(0.15489584207534790039f + |
| x*(0.21345567703247070312f + |
| (2.89795351028442382812f - 2.26661229133605957031f*x)*x)); |
| } |
| |
| static void build_table() { |
| SkDebugf("const uint8_t gByteExpU8Table[256] = {"); |
| for (int i = 0; i <= 255; ++i) { |
| if (!(i % 8)) { |
| SkDebugf("\n"); |
| } |
| int v = (int)(eval_gaussian(i / 255.f) * 256); |
| SkDebugf(" 0x%02X,", v); |
| } |
| SkDebugf("\n};\n"); |
| } |
| |
| const uint8_t gByteExpU8Table[256] = { |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, |
| 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, 0x02, |
| 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04, 0x04, |
| 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x07, |
| 0x07, 0x07, 0x08, 0x08, 0x08, 0x09, 0x09, 0x09, |
| 0x0A, 0x0A, 0x0B, 0x0B, 0x0B, 0x0C, 0x0C, 0x0D, |
| 0x0D, 0x0E, 0x0E, 0x0F, 0x0F, 0x10, 0x10, 0x11, |
| 0x11, 0x12, 0x12, 0x13, 0x14, 0x14, 0x15, 0x15, |
| 0x16, 0x17, 0x17, 0x18, 0x19, 0x19, 0x1A, 0x1B, |
| 0x1C, 0x1C, 0x1D, 0x1E, 0x1F, 0x1F, 0x20, 0x21, |
| 0x22, 0x23, 0x24, 0x24, 0x25, 0x26, 0x27, 0x28, |
| 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, |
| 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x38, 0x39, |
| 0x3A, 0x3B, 0x3C, 0x3D, 0x3F, 0x40, 0x41, 0x42, |
| 0x44, 0x45, 0x46, 0x48, 0x49, 0x4A, 0x4C, 0x4D, |
| 0x4E, 0x50, 0x51, 0x53, 0x54, 0x55, 0x57, 0x58, |
| 0x5A, 0x5B, 0x5D, 0x5E, 0x60, 0x61, 0x63, 0x64, |
| 0x66, 0x68, 0x69, 0x6B, 0x6C, 0x6E, 0x70, 0x71, |
| 0x73, 0x75, 0x76, 0x78, 0x79, 0x7B, 0x7D, 0x7F, |
| 0x80, 0x82, 0x84, 0x85, 0x87, 0x89, 0x8A, 0x8C, |
| 0x8E, 0x90, 0x91, 0x93, 0x95, 0x96, 0x98, 0x9A, |
| 0x9C, 0x9D, 0x9F, 0xA1, 0xA2, 0xA4, 0xA6, 0xA8, |
| 0xA9, 0xAB, 0xAD, 0xAE, 0xB0, 0xB2, 0xB3, 0xB5, |
| 0xB7, 0xB8, 0xBA, 0xBC, 0xBD, 0xBF, 0xC0, 0xC2, |
| 0xC3, 0xC5, 0xC7, 0xC8, 0xCA, 0xCB, 0xCD, 0xCE, |
| 0xCF, 0xD1, 0xD2, 0xD4, 0xD5, 0xD6, 0xD8, 0xD9, |
| 0xDA, 0xDC, 0xDD, 0xDE, 0xDF, 0xE1, 0xE2, 0xE3, |
| 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, |
| 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF0, 0xF1, 0xF2, |
| 0xF3, 0xF3, 0xF4, 0xF5, 0xF5, 0xF6, 0xF6, 0xF7, |
| 0xF7, 0xF8, 0xF8, 0xF9, 0xF9, 0xF9, 0xFA, 0xFA, |
| 0xFA, 0xFA, 0xFA, 0xFB, 0xFB, 0xFB, 0xFB, 0xFB, |
| }; |
| |
| void SkGaussianColorFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const { |
| // to re-build the table, call build_table() which will dump it out using SkDebugf. |
| if (false) { |
| build_table(); |
| } |
| for (int i = 0; i < count; ++i) { |
| SkPMColor c = src[i]; |
| uint8_t a = gByteExpU8Table[SkGetPackedA32(c)]; |
| dst[i] = SkPackARGB32(a, a, a, a); |
| } |
| } |
| |
| void SkGaussianColorFilter::filterSpan4f(const SkPM4f src[], int count, SkPM4f dst[]) const { |
| for (int i = 0; i < count; ++i) { |
| float v = eval_gaussian(src[i].a()); |
| dst[i] = SkPM4f::FromPremulRGBA(v, v, v, v); |
| } |
| } |
| |
| sk_sp<SkFlattenable> SkGaussianColorFilter::CreateProc(SkReadBuffer&) { |
| return Make(); |
| } |
| |
| #ifndef SK_IGNORE_TO_STRING |
| void SkGaussianColorFilter::toString(SkString* str) const { |
| str->append("SkGaussianColorFilter "); |
| } |
| #endif |
| |
| #if SK_SUPPORT_GPU |
| |
| sk_sp<GrFragmentProcessor> SkGaussianColorFilter::asFragmentProcessor(GrContext*, |
| SkColorSpace*) const { |
| return GrBlurredEdgeFP::Make(GrBlurredEdgeFP::kGaussian_Mode); |
| } |
| #endif |
| |
| /////////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| 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 |
| }; |
| |
| 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; |
| } |
| SkFAIL("Uninitialized occluder type?"); |
| return false; |
| } |
| |
| sk_sp<SkVertices> makeVertices(const SkPath& path, const SkMatrix& ctm, |
| SkVector* translate) const { |
| bool transparent = OccluderType::kTransparent == fOccluderType; |
| SkPoint3 zParams = SkPoint3::Make(0, 0, fOccluderHeight); |
| if (ctm.hasPerspective() || OccluderType::kOpaquePartialUmbra == fOccluderType) { |
| translate->set(0, 0); |
| return SkShadowTessellator::MakeSpot(path, ctm, zParams, |
| fDevLightPos, fLightRadius, transparent); |
| } 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); |
| } |
| } |
| }; |
| |
| /** |
| * 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 { SkFAIL("Should never be called"); } |
| bool isRRect(SkRRect* rrect) { return false; } |
| #endif |
| |
| private: |
| const SkPath* fPath; |
| const SkMatrix* fViewMatrix; |
| #if SK_SUPPORT_GPU |
| GrShape fShapeForKey; |
| #endif |
| }; |
| |
| // This creates a domain of keys in SkResourceCache used by this file. |
| static void* kNamespace; |
| |
| /** |
| * 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> |
| void draw_shadow(const FACTORY& factory, |
| std::function<void(const SkVertices*, SkBlendMode, const SkPaint&, |
| SkScalar tx, SkScalar ty)> 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; |
| } |
| auto rec = new CachedTessellationsRec(*key, std::move(tessellations)); |
| SkResourceCache::Add(rec); |
| } else { |
| vertices = factory.makeVertices(path.path(), path.viewMatrix(), |
| &context.fTranslate); |
| if (!vertices) { |
| return; |
| } |
| } |
| } |
| |
| SkPaint paint; |
| // Run the vertex color through a GaussianColorFilter and then modulate the grayscale result of |
| // that against our 'color' param. |
| paint.setColorFilter(SkColorFilter::MakeComposeFilter( |
| SkColorFilter::MakeModeFilter(color, SkBlendMode::kModulate), |
| SkGaussianColorFilter::Make())); |
| |
| drawProc(vertices.get(), SkBlendMode::kModulate, paint, |
| context.fTranslate.fX, context.fTranslate.fY); |
| } |
| } |
| |
| static bool tilted(const SkPoint3& zPlaneParams) { |
| return !SkScalarNearlyZero(zPlaneParams.fX) || !SkScalarNearlyZero(zPlaneParams.fY); |
| } |
| |
| static SkPoint3 map(const SkMatrix& m, const SkPoint3& pt) { |
| SkPoint3 result; |
| m.mapXY(pt.fX, pt.fY, (SkPoint*)&result.fX); |
| result.fZ = pt.fZ; |
| return result; |
| } |
| |
| static SkColor compute_render_color(SkColor color, float alpha) { |
| return SkColorSetARGB(alpha*SkColorGetA(color), SkColorGetR(color), |
| SkColorGetG(color), SkColorGetB(color)); |
| } |
| |
| // 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& devLightPos, SkScalar lightRadius, |
| SkScalar ambientAlpha, SkScalar spotAlpha, SkColor color, |
| uint32_t flags) { |
| SkMatrix inverse; |
| if (!canvas->getTotalMatrix().invert(&inverse)) { |
| return; |
| } |
| SkPoint pt = inverse.mapXY(devLightPos.fX, devLightPos.fY); |
| |
| SkDrawShadowRec rec; |
| rec.fZPlaneParams = zPlaneParams; |
| rec.fLightPos = { pt.fX, pt.fY, devLightPos.fZ }; |
| rec.fLightRadius = lightRadius; |
| rec.fAmbientAlpha = SkScalarToFloat(ambientAlpha); |
| rec.fSpotAlpha = SkScalarToFloat(spotAlpha); |
| rec.fColor = color; |
| rec.fFlags = flags; |
| |
| canvas->private_draw_shadow_rec(path, rec); |
| } |
| |
| void SkBaseDevice::drawShadow(const SkPath& path, const SkDrawShadowRec& rec) { |
| auto drawVertsProc = [this](const SkVertices* vertices, SkBlendMode mode, const SkPaint& paint, |
| SkScalar tx, SkScalar ty) { |
| SkAutoDeviceCTMRestore adr(this, SkMatrix::Concat(this->ctm(), |
| SkMatrix::MakeTrans(tx, ty))); |
| this->drawVertices(vertices, mode, paint); |
| }; |
| |
| SkMatrix viewMatrix = this->ctm(); |
| SkAutoDeviceCTMRestore adr(this, SkMatrix::I()); |
| |
| ShadowedPath shadowedPath(&path, &viewMatrix); |
| |
| bool tiltZPlane = tilted(rec.fZPlaneParams); |
| bool transparent = SkToBool(rec.fFlags & SkShadowFlags::kTransparentOccluder_ShadowFlag); |
| bool uncached = tiltZPlane || path.isVolatile(); |
| |
| SkColor color = rec.fColor; |
| SkPoint3 zPlaneParams = rec.fZPlaneParams; |
| SkPoint3 devLightPos = map(viewMatrix, rec.fLightPos); |
| float lightRadius = rec.fLightRadius; |
| |
| float ambientAlpha = rec.fAmbientAlpha; |
| if (ambientAlpha > 0) { |
| ambientAlpha = SkTMin(ambientAlpha, 1.f); |
| if (uncached) { |
| sk_sp<SkVertices> vertices = SkShadowTessellator::MakeAmbient(path, viewMatrix, |
| zPlaneParams, |
| transparent); |
| SkColor renderColor = compute_render_color(color, ambientAlpha); |
| SkPaint paint; |
| // Run the vertex color through a GaussianColorFilter and then modulate the grayscale |
| // result of that against our 'color' param. |
| paint.setColorFilter(SkColorFilter::MakeComposeFilter( |
| SkColorFilter::MakeModeFilter(renderColor, SkBlendMode::kModulate), |
| SkGaussianColorFilter::Make())); |
| this->drawVertices(vertices.get(), SkBlendMode::kModulate, paint); |
| } else { |
| 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(); |
| } |
| |
| SkColor renderColor = compute_render_color(color, ambientAlpha); |
| draw_shadow(factory, drawVertsProc, shadowedPath, renderColor); |
| } |
| } |
| |
| float spotAlpha = rec.fSpotAlpha; |
| if (spotAlpha > 0) { |
| spotAlpha = SkTMin(spotAlpha, 1.f); |
| if (uncached) { |
| sk_sp<SkVertices> vertices = SkShadowTessellator::MakeSpot(path, viewMatrix, |
| zPlaneParams, |
| devLightPos, lightRadius, |
| transparent); |
| SkColor renderColor = compute_render_color(color, spotAlpha); |
| SkPaint paint; |
| // Run the vertex color through a GaussianColorFilter and then modulate the grayscale |
| // result of that against our 'color' param. |
| paint.setColorFilter(SkColorFilter::MakeComposeFilter( |
| SkColorFilter::MakeModeFilter(renderColor, SkBlendMode::kModulate), |
| SkGaussianColorFilter::Make())); |
| this->drawVertices(vertices.get(), SkBlendMode::kModulate, paint); |
| } else { |
| SpotVerticesFactory factory; |
| SkScalar occluderHeight = zPlaneParams.fZ; |
| float zRatio = SkTPin(occluderHeight / (devLightPos.fZ - occluderHeight), 0.0f, 0.95f); |
| SkScalar radius = lightRadius * zRatio; |
| |
| // Compute the scale and translation for the spot shadow. |
| SkScalar scale = devLightPos.fZ / (devLightPos.fZ - occluderHeight); |
| SkPoint center = SkPoint::Make(path.getBounds().centerX(), path.getBounds().centerY()); |
| factory.fLocalCenter = center; |
| viewMatrix.mapPoints(¢er, 1); |
| factory.fOffset = SkVector::Make(zRatio * (center.fX - devLightPos.fX), |
| zRatio * (center.fY - devLightPos.fY)); |
| factory.fOccluderHeight = occluderHeight; |
| factory.fDevLightPos = devLightPos; |
| factory.fLightRadius = lightRadius; |
| SkRect devBounds; |
| viewMatrix.mapRect(&devBounds, path.getBounds()); |
| 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 { |
| factory.fOccluderType = SpotVerticesFactory::OccluderType::kOpaquePartialUmbra; |
| } |
| // need to add this after we classify the shadow |
| factory.fOffset.fX += viewMatrix.getTranslateX(); |
| factory.fOffset.fY += viewMatrix.getTranslateY(); |
| #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; |
| } |
| #endif |
| SkColor renderColor = compute_render_color(color, spotAlpha); |
| draw_shadow(factory, drawVertsProc, shadowedPath, renderColor); |
| } |
| } |
| } |
