summaryrefslogtreecommitdiffstats
path: root/gfx/skia/skia/src/shaders/SkShaderBase.h
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--gfx/skia/skia/src/shaders/SkShaderBase.h494
1 files changed, 494 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/shaders/SkShaderBase.h b/gfx/skia/skia/src/shaders/SkShaderBase.h
new file mode 100644
index 0000000000..d6348c2859
--- /dev/null
+++ b/gfx/skia/skia/src/shaders/SkShaderBase.h
@@ -0,0 +1,494 @@
+/*
+ * 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/SkMatrix.h"
+#include "include/core/SkPaint.h"
+#include "include/core/SkSamplingOptions.h"
+#include "include/core/SkShader.h"
+#include "include/core/SkSurfaceProps.h"
+#include "include/private/base/SkNoncopyable.h"
+#include "src/base/SkTLazy.h"
+#include "src/core/SkEffectPriv.h"
+#include "src/core/SkMask.h"
+#include "src/core/SkVM_fwd.h"
+
+#include <tuple>
+
+class GrFragmentProcessor;
+struct GrFPArgs;
+class SkArenaAlloc;
+class SkColorSpace;
+class SkImage;
+struct SkImageInfo;
+class SkPaint;
+class SkRasterPipeline;
+class SkRuntimeEffect;
+class SkStageUpdater;
+class SkUpdatableShader;
+
+namespace skgpu::graphite {
+class KeyContext;
+class PaintParamsKeyBuilder;
+class PipelineDataGatherer;
+}
+
+#if defined(SK_GANESH)
+using GrFPResult = std::tuple<bool /*success*/, std::unique_ptr<GrFragmentProcessor>>;
+#endif
+
+class SkShaderBase : public SkShader {
+public:
+ ~SkShaderBase() override;
+
+ sk_sp<SkShader> makeInvertAlpha() const;
+ sk_sp<SkShader> makeWithCTM(const SkMatrix&) const; // owns its own ctm
+
+ /**
+ * Returns true if the shader is guaranteed to produce only a single color.
+ * Subclasses can override this to allow loop-hoisting optimization.
+ */
+ virtual bool isConstant() const { return false; }
+
+ enum class GradientType {
+ kNone,
+ kColor,
+ kLinear,
+ kRadial,
+ kSweep,
+ kConical
+ };
+
+ /**
+ * If the shader subclass can be represented as a gradient, asGradient
+ * returns the matching GradientType enum (or GradientType::kNone if it
+ * cannot). Also, if info is not null, asGradient populates info with
+ * the relevant (see below) parameters for the gradient. fColorCount
+ * is both an input and output parameter. On input, it indicates how
+ * many entries in fColors and fColorOffsets can be used, if they are
+ * non-NULL. After asGradient has run, fColorCount indicates how
+ * many color-offset pairs there are in the gradient. If there is
+ * insufficient space to store all of the color-offset pairs, fColors
+ * and fColorOffsets will not be altered. fColorOffsets specifies
+ * where on the range of 0 to 1 to transition to the given color.
+ * The meaning of fPoint and fRadius is dependent on the type of gradient.
+ *
+ * None:
+ * info is ignored.
+ * Color:
+ * fColorOffsets[0] is meaningless.
+ * Linear:
+ * fPoint[0] and fPoint[1] are the end-points of the gradient
+ * Radial:
+ * fPoint[0] and fRadius[0] are the center and radius
+ * Conical:
+ * fPoint[0] and fRadius[0] are the center and radius of the 1st circle
+ * fPoint[1] and fRadius[1] are the center and radius of the 2nd circle
+ * Sweep:
+ * fPoint[0] is the center of the sweep.
+ */
+ struct GradientInfo {
+ int fColorCount = 0; //!< In-out parameter, specifies passed size
+ // of fColors/fColorOffsets on input, and
+ // actual number of colors/offsets on
+ // output.
+ SkColor* fColors = nullptr; //!< The colors in the gradient.
+ SkScalar* fColorOffsets = nullptr; //!< The unit offset for color transitions.
+ SkPoint fPoint[2]; //!< Type specific, see above.
+ SkScalar fRadius[2]; //!< Type specific, see above.
+ SkTileMode fTileMode;
+ uint32_t fGradientFlags = 0; //!< see SkGradientShader::Flags
+ };
+
+ virtual GradientType asGradient(GradientInfo* info = nullptr,
+ SkMatrix* localMatrix = nullptr) const {
+ return GradientType::kNone;
+ }
+
+ enum Flags {
+ //!< set if all of the colors will be opaque
+ kOpaqueAlpha_Flag = 1 << 0,
+
+ /** set if the spans only vary in X (const in Y).
+ e.g. an Nx1 bitmap that is being tiled in Y, or a linear-gradient
+ that varies from left-to-right. This flag specifies this for
+ shadeSpan().
+ */
+ kConstInY32_Flag = 1 << 1,
+
+ /** hint for the blitter that 4f is the preferred shading mode.
+ */
+ kPrefers4f_Flag = 1 << 2,
+ };
+
+ /**
+ * ContextRec acts as a parameter bundle for creating Contexts.
+ */
+ struct ContextRec {
+ ContextRec(const SkColor4f& paintColor, const SkMatrix& matrix, const SkMatrix* localM,
+ SkColorType dstColorType, SkColorSpace* dstColorSpace, SkSurfaceProps props)
+ : fMatrix(&matrix)
+ , fLocalMatrix(localM)
+ , fDstColorType(dstColorType)
+ , fDstColorSpace(dstColorSpace)
+ , fProps(props) {
+ fPaintAlpha = SkColorGetA(paintColor.toSkColor());
+ }
+
+ const SkMatrix* fMatrix; // the current matrix in the canvas
+ const SkMatrix* fLocalMatrix; // optional local matrix
+ SkColorType fDstColorType; // the color type of the dest surface
+ SkColorSpace* fDstColorSpace; // the color space of the dest surface (if any)
+ SkSurfaceProps fProps; // props of the dest surface
+ SkAlpha fPaintAlpha;
+
+ bool isLegacyCompatible(SkColorSpace* shadersColorSpace) const;
+ };
+
+ class Context : public ::SkNoncopyable {
+ public:
+ Context(const SkShaderBase& shader, const ContextRec&);
+
+ virtual ~Context();
+
+ /**
+ * Called sometimes before drawing with this shader. Return the type of
+ * alpha your shader will return. The default implementation returns 0.
+ * Your subclass should override if it can (even sometimes) report a
+ * non-zero value, since that will enable various blitters to perform
+ * faster.
+ */
+ virtual uint32_t getFlags() const { return 0; }
+
+ /**
+ * Called for each span of the object being drawn. Your subclass should
+ * set the appropriate colors (with premultiplied alpha) that correspond
+ * to the specified device coordinates.
+ */
+ virtual void shadeSpan(int x, int y, SkPMColor[], int count) = 0;
+
+ protected:
+ // Reference to shader, so we don't have to dupe information.
+ const SkShaderBase& fShader;
+
+ uint8_t getPaintAlpha() const { return fPaintAlpha; }
+ const SkMatrix& getTotalInverse() const { return fTotalInverse; }
+ const SkMatrix& getCTM() const { return fCTM; }
+
+ private:
+ SkMatrix fCTM;
+ SkMatrix fTotalInverse;
+ uint8_t fPaintAlpha;
+
+ using INHERITED = SkNoncopyable;
+ };
+
+ /**
+ * This is used to accumulate matrices, starting with the CTM, when building up
+ * SkRasterPipeline, SkVM, and 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", which 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 {
+ public:
+ MatrixRec() = default;
+
+ explicit MatrixRec(const SkMatrix& ctm);
+
+ /**
+ * Returns a new MatrixRec that represents the existing total and pending matrix
+ * pre-concat'ed with m.
+ */
+ MatrixRec SK_WARN_UNUSED_RESULT concat(const SkMatrix& m) const;
+
+ /**
+ * Appends a mul by the inverse of the pending local matrix to the pipeline. 'postInv' is an
+ * additional matrix to post-apply to the inverted pending matrix. If the pending matrix is
+ * not invertible the std::optional result won't have a value and the pipeline will be
+ * unmodified.
+ */
+ std::optional<MatrixRec> SK_WARN_UNUSED_RESULT apply(const SkStageRec& rec,
+ const SkMatrix& postInv = {}) const;
+
+ /**
+ * Muls local by the inverse of the pending matrix. 'postInv' is an additional matrix to
+ * post-apply to the inverted pending matrix. If the pending matrix is not invertible the
+ * std::optional result won't have a value and the Builder will be unmodified.
+ */
+ std::optional<MatrixRec> SK_WARN_UNUSED_RESULT apply(skvm::Builder*,
+ skvm::Coord* local, // inout
+ skvm::Uniforms*,
+ const SkMatrix& postInv = {}) const;
+
+#if defined(SK_GANESH)
+ /**
+ * Produces an FP that muls its input coords by the inverse of the pending matrix and then
+ * samples the passed FP with those coordinates. 'postInv' is an additional matrix to
+ * post-apply to the inverted pending matrix. If the pending matrix is not invertible the
+ * GrFPResult's bool will be false and the passed FP will be returned to the caller in the
+ * GrFPResult.
+ */
+ GrFPResult SK_WARN_UNUSED_RESULT apply(std::unique_ptr<GrFragmentProcessor>,
+ const SkMatrix& postInv = {}) const;
+ /**
+ * A parent FP may need to create a FP for its child by calling
+ * SkShaderBase::asFragmentProcessor() and then pass the result to the apply() above.
+ * This comes up when the parent needs to ensure pending matrices are applied before the
+ * child because the parent is going to manipulate the coordinates *after* any pending
+ * matrix and pass the resulting coords to the child. This function gets a MatrixRec that
+ * reflects the state after this MatrixRec has bee applied but it does not apply it!
+ * Example:
+ * auto childFP = fChild->asFragmentProcessor(args, mrec.applied());
+ * childFP = MakeAWrappingFPThatModifiesChildsCoords(std::move(childFP));
+ * auto [success, parentFP] = mrec.apply(std::move(childFP));
+ */
+ MatrixRec applied() const;
+#endif
+
+ /** Call to indicate that the mapping from shader to device space is not known. */
+ void markTotalMatrixInvalid() { fTotalMatrixIsValid = false; }
+
+ /** Marks the CTM as already applied; can avoid re-seeding the shader unnecessarily. */
+ void markCTMApplied() { fCTMApplied = true; }
+
+ /**
+ * Indicates whether the total matrix of a MatrixRec passed to a SkShader actually
+ * represents the full transform between that shader's coordinate space and device space.
+ */
+ bool totalMatrixIsValid() const { return fTotalMatrixIsValid; }
+
+ /**
+ * Gets the total transform from the current shader's space to device space. This may or
+ * may not be valid. Shaders should avoid making decisions based on this matrix if
+ * totalMatrixIsValid() is false.
+ */
+ SkMatrix totalMatrix() const { return SkMatrix::Concat(fCTM, fTotalLocalMatrix); }
+
+ /** Gets the inverse of totalMatrix(), if invertible. */
+ bool SK_WARN_UNUSED_RESULT totalInverse(SkMatrix* out) const {
+ return this->totalMatrix().invert(out);
+ }
+
+ /** Is there a transform that has not yet been applied by a parent shader? */
+ bool hasPendingMatrix() const {
+ return (!fCTMApplied && !fCTM.isIdentity()) || !fPendingLocalMatrix.isIdentity();
+ }
+
+ /** When generating raster pipeline, have the device coordinates been seeded? */
+ bool rasterPipelineCoordsAreSeeded() const { return fCTMApplied; }
+
+ private:
+ MatrixRec(const SkMatrix& ctm,
+ const SkMatrix& totalLocalMatrix,
+ const SkMatrix& pendingLocalMatrix,
+ bool totalIsValid,
+ bool ctmApplied)
+ : fCTM(ctm)
+ , fTotalLocalMatrix(totalLocalMatrix)
+ , fPendingLocalMatrix(pendingLocalMatrix)
+ , fTotalMatrixIsValid(totalIsValid)
+ , fCTMApplied(ctmApplied) {}
+
+ const SkMatrix fCTM;
+
+ // Concatenation of all local matrices, including those already applied.
+ const SkMatrix fTotalLocalMatrix;
+
+ // The accumulated local matrices from walking down the shader hierarchy that have NOT yet
+ // been incorporated into the SkRasterPipeline.
+ const SkMatrix fPendingLocalMatrix;
+
+ bool fTotalMatrixIsValid = true;
+
+ // Tracks whether the CTM has already been applied (and in raster pipeline whether the
+ // device coords have been seeded.)
+ bool fCTMApplied = false;
+ };
+
+ /**
+ * Make a context using the memory provided by the arena.
+ *
+ * @return pointer to context or nullptr if can't be created
+ */
+ Context* makeContext(const ContextRec&, SkArenaAlloc*) const;
+
+#if defined(SK_GANESH)
+ /**
+ * Call on the root SkShader to produce a GrFragmentProcessor.
+ *
+ * The returned GrFragmentProcessor expects an unpremultiplied input color and produces a
+ * premultiplied output.
+ */
+ std::unique_ptr<GrFragmentProcessor> asRootFragmentProcessor(const GrFPArgs&,
+ const SkMatrix& ctm) const;
+ /**
+ * Virtualized implementation of above. Any pending matrix in the MatrixRec should be applied
+ * to the coords if the SkShader uses its coordinates. This can be done by calling
+ * MatrixRec::apply() to wrap a GrFragmentProcessor in a GrMatrixEffect.
+ */
+ virtual std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&,
+ const MatrixRec&) const;
+#endif
+
+ /**
+ * If the shader can represent its "average" luminance in a single color, return true and
+ * if color is not NULL, return that color. If it cannot, return false and ignore the color
+ * parameter.
+ *
+ * Note: if this returns true, the returned color will always be opaque, as only the RGB
+ * components are used to compute luminance.
+ */
+ bool asLuminanceColor(SkColor*) const;
+
+ /**
+ * If this returns false, then we draw nothing (do not fall back to shader context). This should
+ * only be called on a root-level effect. It assumes that the initial device coordinates have
+ * not yet been seeded.
+ */
+ SK_WARN_UNUSED_RESULT
+ bool appendRootStages(const SkStageRec& rec, const SkMatrix& ctm) const;
+
+ /**
+ * Adds stages to implement this shader. To ensure that the correct input coords are present
+ * in r,g MatrixRec::apply() must be called (unless the shader doesn't require it's input
+ * coords). The default impl creates shadercontext and calls that (not very efficient).
+ */
+ virtual bool appendStages(const SkStageRec&, const MatrixRec&) const;
+
+ bool SK_WARN_UNUSED_RESULT computeTotalInverse(const SkMatrix& ctm,
+ const SkMatrix* localMatrix,
+ SkMatrix* totalInverse) const;
+
+ virtual SkImage* onIsAImage(SkMatrix*, SkTileMode[2]) const {
+ return nullptr;
+ }
+
+ virtual SkRuntimeEffect* asRuntimeEffect() const { return nullptr; }
+
+ static Type GetFlattenableType() { return kSkShader_Type; }
+ Type getFlattenableType() const override { return GetFlattenableType(); }
+
+ static sk_sp<SkShaderBase> Deserialize(const void* data, size_t size,
+ const SkDeserialProcs* procs = nullptr) {
+ return sk_sp<SkShaderBase>(static_cast<SkShaderBase*>(
+ SkFlattenable::Deserialize(GetFlattenableType(), data, size, procs).release()));
+ }
+ static void RegisterFlattenables();
+
+ /** DEPRECATED. skbug.com/8941
+ * If this shader can be represented by another shader + a localMatrix, return that shader and
+ * the localMatrix. If not, return nullptr and ignore the localMatrix parameter.
+ */
+ virtual sk_sp<SkShader> makeAsALocalMatrixShader(SkMatrix* localMatrix) const;
+
+ /**
+ * Called at the root of a shader tree to build a VM that produces color. The device coords
+ * should be initialized to the centers of device space pixels being shaded and the inverse of
+ * ctm should be the transform of those coords to local space.
+ */
+ SK_WARN_UNUSED_RESULT
+ skvm::Color rootProgram(skvm::Builder*,
+ skvm::Coord device,
+ skvm::Color paint,
+ const SkMatrix& ctm,
+ const SkColorInfo& dst,
+ skvm::Uniforms* uniforms,
+ SkArenaAlloc* alloc) const;
+
+ /**
+ * Virtualized implementation of above. A note on the local coords param: it must be transformed
+ * by the inverse of the "pending" matrix in MatrixRec to be put in the correct space for this
+ * shader. This is done by calling MatrixRec::apply().
+ */
+ virtual skvm::Color program(skvm::Builder*,
+ skvm::Coord device,
+ skvm::Coord local,
+ skvm::Color paint,
+ const MatrixRec&,
+ const SkColorInfo& dst,
+ skvm::Uniforms*,
+ SkArenaAlloc*) const = 0;
+
+#if defined(SK_GRAPHITE)
+ /**
+ Add implementation details, for the specified backend, of this SkShader to the
+ provided key.
+
+ @param keyContext backend context for key creation
+ @param builder builder for creating the key for this SkShader
+ @param gatherer if non-null, storage for this shader's data
+ */
+ virtual void addToKey(const skgpu::graphite::KeyContext& keyContext,
+ skgpu::graphite::PaintParamsKeyBuilder* builder,
+ skgpu::graphite::PipelineDataGatherer* gatherer) const;
+#endif
+
+ static SkMatrix ConcatLocalMatrices(const SkMatrix& parentLM, const SkMatrix& childLM) {
+#if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK) // b/256873449
+ return SkMatrix::Concat(childLM, parentLM);
+#endif
+ return SkMatrix::Concat(parentLM, childLM);
+ }
+
+protected:
+ SkShaderBase();
+
+ void flatten(SkWriteBuffer&) const override;
+
+#ifdef SK_ENABLE_LEGACY_SHADERCONTEXT
+ /**
+ * Specialize creating a SkShader context using the supplied allocator.
+ * @return pointer to context owned by the arena allocator.
+ */
+ virtual Context* onMakeContext(const ContextRec&, SkArenaAlloc*) const {
+ return nullptr;
+ }
+#endif
+
+ virtual bool onAsLuminanceColor(SkColor*) const {
+ return false;
+ }
+
+protected:
+ static skvm::Coord ApplyMatrix(skvm::Builder*, const SkMatrix&, skvm::Coord, skvm::Uniforms*);
+
+ using INHERITED = SkShader;
+};
+inline SkShaderBase* as_SB(SkShader* shader) {
+ return static_cast<SkShaderBase*>(shader);
+}
+
+inline const SkShaderBase* as_SB(const SkShader* shader) {
+ return static_cast<const SkShaderBase*>(shader);
+}
+
+inline const SkShaderBase* as_SB(const sk_sp<SkShader>& shader) {
+ return static_cast<SkShaderBase*>(shader.get());
+}
+
+void SkRegisterColor4ShaderFlattenable();
+void SkRegisterColorShaderFlattenable();
+void SkRegisterComposeShaderFlattenable();
+void SkRegisterCoordClampShaderFlattenable();
+void SkRegisterEmptyShaderFlattenable();
+
+#endif // SkShaderBase_DEFINED
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-09 16:21:42 +0000