/*
* 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 "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(
GrContext*, 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(
GrContext*, 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;
/**
* 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)> 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));
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);
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) {
if (vertices->vertexCount()) {
SkAutoDeviceCTMRestore adr(this, 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);
}
}
}
}