chromium/third_party/skia/src/shaders/SkShaderBase.h

/*
 * Copyright 2017 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkShaderBase_DEFINED
#define SkShaderBase_DEFINED

#include "include/core/SkColor.h"
#include "include/core/SkFlattenable.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkSurfaceProps.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkNoncopyable.h"

#include <cstddef>
#include <cstdint>
#include <optional>
#include <tuple>

class SkArenaAlloc;
class SkColorSpace;
class SkImage;
class SkRuntimeEffect;
class SkWriteBuffer;
enum SkColorType : int;
enum class SkTileMode;
struct SkDeserialProcs;
struct SkStageRec;

namespace SkShaders {
/**
 * This is used to accumulate matrices, starting with the CTM, when building up
 * SkRasterPipeline or GrFragmentProcessor by walking the SkShader tree. It avoids
 * adding a matrix multiply for each individual matrix. It also handles the reverse matrix
 * concatenation order required by Android Framework, see b/256873449.
 *
 * This also tracks the dubious concept of a "total matrix", in the legacy Context/shadeSpan system.
 * That includes all the matrices encountered during traversal to the current shader, including ones
 * that have already been applied. The total matrix represents the transformation from the current
 * shader's coordinate space to device space. It is dubious because it doesn't account for SkShaders
 * that manipulate the coordinates passed to their children, which may not even be representable by
 * a matrix.
 *
 * The total matrix is used for mipmap level selection and a filter downgrade optimizations in
 * SkImageShader and sizing of the SkImage created by SkPictureShader. If we can remove usages
 * of the "total matrix" and if Android Framework could be updated to not use backwards local
 * matrix concatenation this could just be replaced by a simple SkMatrix or SkM44 passed down
 * during traversal.
 */
class MatrixRec { … };

}  // namespace SkShaders

#define SK_ALL_SHADERS(M) …

#define SK_ALL_GRADIENTS(M) …

class SkShaderBase : public SkShader { … };
inline SkShaderBase* as_SB(SkShader* shader) { … }

inline const SkShaderBase* as_SB(const SkShader* shader) { … }

inline const SkShaderBase* as_SB(const sk_sp<SkShader>& shader) { … }

void SkRegisterBlendShaderFlattenable();
void SkRegisterColor4ShaderFlattenable();
void SkRegisterColorShaderFlattenable();
void SkRegisterCoordClampShaderFlattenable();
void SkRegisterEmptyShaderFlattenable();
void SkRegisterPerlinNoiseShaderFlattenable();
void SkRegisterWorkingColorSpaceShaderFlattenable();

#endif // SkShaderBase_DEFINED