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* Copyright 2012 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef SkGradientShaderPriv_DEFINED
#define SkGradientShaderPriv_DEFINED
#include "include/core/SkBitmap.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/effects/SkGradientShader.h"
#include "include/private/SkColorData.h"
#include "include/private/base/SkAssert.h"
#include "include/private/base/SkTArray.h"
#include "include/private/base/SkTemplates.h"
#include "src/shaders/SkShaderBase.h"
#include <cstddef>
#include <cstdint>
class SkArenaAlloc;
class SkRasterPipeline;
class SkReadBuffer;
class SkShader;
class SkWriteBuffer;
enum class SkTileMode;
struct SkStageRec;
class SkGradientBaseShader : public SkShaderBase {
using Interpolation = SkGradientShader::Interpolation;
struct Descriptor {
Descriptor(const SkColor4f colors[],
sk_sp<SkColorSpace> colorSpace,
const SkScalar positions[],
int colorCount,
SkTileMode mode,
const Interpolation& interpolation);
const SkColor4f* fColors;
sk_sp<SkColorSpace> fColorSpace;
const SkScalar* fPositions;
int fColorCount; // length of fColors (and fPositions, if not nullptr)
SkTileMode fTileMode;
Interpolation fInterpolation;
class DescriptorScope : public Descriptor {
DescriptorScope() {}
bool unflatten(SkReadBuffer&, SkMatrix* legacyLocalMatrix);
skia_private::STArray<16, SkColor4f> fColorStorage;
skia_private::STArray<16, SkScalar> fPositionStorage;
SkGradientBaseShader(const Descriptor& desc, const SkMatrix& ptsToUnit);
~SkGradientBaseShader() override;
ShaderType type() const final { return ShaderType::kGradientBase; }
bool isOpaque() const override;
bool interpolateInPremul() const {
return fInterpolation.fInPremul == SkGradientShader::Interpolation::InPremul::kYes;
const SkMatrix& getGradientMatrix() const { return fPtsToUnit; }
int getColorCount() const { return fColorCount; }
const float* getPositions() const { return fPositions; }
const Interpolation& getInterpolation() const { return fInterpolation; }
static bool ValidGradient(const SkColor4f colors[],
int count,
SkTileMode tileMode,
const Interpolation& interpolation);
static sk_sp<SkShader> MakeDegenerateGradient(const SkColor4f colors[],
const SkScalar pos[],
int colorCount,
sk_sp<SkColorSpace> colorSpace,
SkTileMode mode);
// The default SkScalarNearlyZero threshold of .0024 is too big and causes regressions for svg
// gradients defined in the wild.
static constexpr SkScalar kDegenerateThreshold = SK_Scalar1 / (1 << 15);
void flatten(SkWriteBuffer&) const override;
void commonAsAGradient(GradientInfo*) const;
bool onAsLuminanceColor(SkColor4f*) const override;
bool appendStages(const SkStageRec&, const SkShaders::MatrixRec&) const override;
virtual void appendGradientStages(SkArenaAlloc* alloc,
SkRasterPipeline* tPipeline,
SkRasterPipeline* postPipeline) const = 0;
const SkMatrix fPtsToUnit;
SkTileMode fTileMode;
static void AppendGradientFillStages(SkRasterPipeline* p,
SkArenaAlloc* alloc,
const SkPMColor4f* colors,
const SkScalar* positions,
int count);
static void AppendInterpolatedToDstStages(SkRasterPipeline* p,
SkArenaAlloc* alloc,
bool colorsAreOpaque,
const Interpolation& interpolation,
const SkColorSpace* intermediateColorSpace,
const SkColorSpace* dstColorSpace);
SkScalar getPos(int i) const {
SkASSERT(i < fColorCount);
return fPositions ? fPositions[i] : SkIntToScalar(i) / (fColorCount - 1);
SkColor getLegacyColor(int i) const {
SkASSERT(i < fColorCount);
return fColors[i].toSkColor();
SkColor4f* fColors; // points into fStorage
SkScalar* fPositions; // points into fStorage, or nullptr
int fColorCount; // length of fColors (and fPositions, if not nullptr)
sk_sp<SkColorSpace> fColorSpace; // color space of gradient stops
Interpolation fInterpolation;
bool fFirstStopIsImplicit;
bool fLastStopIsImplicit;
bool colorsAreOpaque() const { return fColorsAreOpaque; }
SkTileMode getTileMode() const { return fTileMode; }
const SkBitmap& cachedBitmap() const { return fColorsAndOffsetsBitmap; }
void setCachedBitmap(SkBitmap b) const { fColorsAndOffsetsBitmap = b; }
// When the number of stops exceeds Graphite's uniform-based limit the colors and offsets
// are stored in this bitmap. It is stored in the shader so it can be cached with a stable
// id and easily regenerated if purged.
// TODO(b/293160919) remove this field when we can store bitmaps in the cache by id.
mutable SkBitmap fColorsAndOffsetsBitmap;
// Reserve inline space for up to 4 stops.
inline static constexpr size_t kInlineStopCount = 4;
inline static constexpr size_t kInlineStorageSize =
(sizeof(SkColor4f) + sizeof(SkScalar)) * kInlineStopCount;
skia_private::AutoSTMalloc<kInlineStorageSize, uint8_t> fStorage;
bool fColorsAreOpaque;
struct SkColor4fXformer {
SkColor4fXformer(const SkGradientBaseShader* shader,
SkColorSpace* dst,
bool forceExplicitPositions = false);
using ColorStorage = skia_private::STArray<4, SkPMColor4f>;
using PositionStorage = skia_private::STArray<4, float>;
ColorStorage fColors;
PositionStorage fPositionStorage;
float* fPositions;
sk_sp<SkColorSpace> fIntermediateColorSpace;
struct SkColorConverter {
SkColorConverter(const SkColor* colors, int count);
skia_private::STArray<2, SkColor4f> fColors4f;
void SkRegisterConicalGradientShaderFlattenable();
void SkRegisterLinearGradientShaderFlattenable();
void SkRegisterRadialGradientShaderFlattenable();
void SkRegisterSweepGradientShaderFlattenable();