/*
|
* 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 "SkBlurMask.h"
|
#include "SkCanvas.h"
|
#include "SkColorFilter.h"
|
#include "SkColorData.h"
|
#include "SkDevice.h"
|
#include "SkDrawShadowInfo.h"
|
#include "SkMaskFilter.h"
|
#include "SkPath.h"
|
#include "SkPathPriv.h"
|
#include "SkRandom.h"
|
#include "SkRasterPipeline.h"
|
#include "SkResourceCache.h"
|
#include "SkShadowTessellator.h"
|
#include "SkString.h"
|
#include "SkTLazy.h"
|
#include "SkVertices.h"
|
#include <new>
|
#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 SkGaussianColorFilter : public SkColorFilter {
|
public:
|
static sk_sp<SkColorFilter> Make() {
|
return sk_sp<SkColorFilter>(new SkGaussianColorFilter);
|
}
|
|
#if SK_SUPPORT_GPU
|
std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(
|
GrRecordingContext*, const GrColorSpaceInfo&) const override;
|
#endif
|
|
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:
|
SK_FLATTENABLE_HOOKS(SkGaussianColorFilter)
|
|
SkGaussianColorFilter() : INHERITED() {}
|
|
typedef SkColorFilter INHERITED;
|
};
|
|
sk_sp<SkFlattenable> SkGaussianColorFilter::CreateProc(SkReadBuffer&) {
|
return Make();
|
}
|
|
#if SK_SUPPORT_GPU
|
|
std::unique_ptr<GrFragmentProcessor> SkGaussianColorFilter::asFragmentProcessor(
|
GrRecordingContext*, const GrColorSpaceInfo&) const {
|
return GrBlurredEdgeFragmentProcessor::Make(GrBlurredEdgeFragmentProcessor::Mode::kGaussian);
|
}
|
#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;
|
}
|
SK_ABORT("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 { SK_ABORT("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;
|
|
// When the SkPathRef genID changes, invalidate a corresponding GrResource described by key.
|
class ShadowInvalidator : public SkPathRef::GenIDChangeListener {
|
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 onChange() 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(
|
SkColorFilter::MakeModeFilter(color, SkBlendMode::kModulate)->makeComposed(
|
SkGaussianColorFilter::Make()));
|
|
drawProc(vertices.get(), SkBlendMode::kModulate, paint,
|
context.fTranslate.fX, context.fTranslate.fY, path.viewMatrix().hasPerspective());
|
|
return true;
|
}
|
}
|
|
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;
|
}
|
|
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 = SkTMax(SkTMax(spotR, spotG), spotB);
|
int min = SkTMin(SkTMin(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);
|
}
|
|
// 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,
|
SkColor ambientColor, SkColor spotColor,
|
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.fAmbientColor = ambientColor;
|
rec.fSpotColor = spotColor;
|
rec.fFlags = flags;
|
|
canvas->private_draw_shadow_rec(path, rec);
|
}
|
|
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->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.
|
SkAutoDeviceCTMRestore adr(
|
this,
|
hasPerspective ? SkMatrix::I()
|
: SkMatrix::Concat(this->ctm(), SkMatrix::MakeTrans(tx, ty)));
|
this->drawVertices(vertices, nullptr, 0, mode, paint);
|
}
|
};
|
|
if (!validate_rec(rec)) {
|
return;
|
}
|
|
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();
|
|
SkPoint3 zPlaneParams = rec.fZPlaneParams;
|
SkPoint3 devLightPos = map(viewMatrix, rec.fLightPos);
|
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(
|
SkColorFilter::MakeModeFilter(rec.fAmbientColor,
|
SkBlendMode::kModulate)->makeComposed(
|
SkGaussianColorFilter::Make()));
|
this->drawVertices(vertices.get(), nullptr, 0, 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);
|
|
// 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);
|
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(
|
SkColorFilter::MakeModeFilter(rec.fSpotColor,
|
SkBlendMode::kModulate)->makeComposed(
|
SkGaussianColorFilter::Make()));
|
this->drawVertices(vertices.get(), nullptr, 0, 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;
|
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 (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;
|
}
|
#endif
|
if (!draw_shadow(factory, drawVertsProc, shadowedPath, color)) {
|
// draw with blur
|
SkMatrix shadowMatrix;
|
if (!SkDrawShadowMetrics::GetSpotShadowTransform(devLightPos, lightRadius,
|
viewMatrix, zPlaneParams,
|
path.getBounds(),
|
&shadowMatrix, &radius)) {
|
return;
|
}
|
SkAutoDeviceCTMRestore 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);
|
}
|
}
|
}
|
}
|
