blob: 2efd57c76e934e1d763e0de072e6112baba5d443 [file] [log] [blame]
* 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 GrSimpleMeshDrawOpHelper_DEFINED
#define GrSimpleMeshDrawOpHelper_DEFINED
#include "GrMeshDrawOp.h"
#include "GrOpFlushState.h"
#include "GrPipeline.h"
struct SkRect;
* This class can be used to help implement simple mesh draw ops. It reduces the amount of
* boilerplate code to type and also provides a mechanism for optionally allocating space for a
* GrProcessorSet based on a GrPaint. It is intended to be used by ops that construct a single
* GrPipeline for a uniform primitive color and a GrPaint.
class GrSimpleMeshDrawOpHelper {
struct MakeArgs;
* This can be used by a Op class to perform allocation and initialization such that a
* GrProcessorSet (if required) is allocated as part of the the same allocation that as
* the Op instance. It requires that Op implements a constructor of the form:
* Op(MakeArgs, GrColor, OpArgs...)
* which is public or made accessible via 'friend'.
template <typename Op, typename... OpArgs>
static std::unique_ptr<GrDrawOp> FactoryHelper(GrPaint&& paint, OpArgs... opArgs);
enum class Flags : uint32_t {
kNone = 0x0,
kSnapVerticesToPixelCenters = 0x1,
GrSimpleMeshDrawOpHelper(const MakeArgs&, GrAAType, Flags = Flags::kNone);
GrSimpleMeshDrawOpHelper() = delete;
GrSimpleMeshDrawOpHelper(const GrSimpleMeshDrawOpHelper&) = delete;
GrSimpleMeshDrawOpHelper& operator=(const GrSimpleMeshDrawOpHelper&) = delete;
GrDrawOp::FixedFunctionFlags fixedFunctionFlags() const;
bool isCompatible(const GrSimpleMeshDrawOpHelper& that, const GrCaps&, const SkRect& thisBounds,
const SkRect& thatBounds) const;
* Finalizes the processor set and determines whether the destination must be provided
* to the fragment shader as a texture for blending.
* @param geometryCoverage Describes the coverage output of the op's geometry processor
* @param geometryColor An in/out param. As input this informs processor analysis about the
* color the op expects to output from its geometry processor. As output
* this may be set to a known color in which case the op must output this
* color from its geometry processor instead.
GrDrawOp::RequiresDstTexture xpRequiresDstTexture(const GrCaps& caps, const GrAppliedClip* clip,
GrProcessorAnalysisCoverage geometryCoverage,
GrProcessorAnalysisColor* geometryColor);
* Version of above that can be used by ops that have a constant color geometry processor
* output. The op passes this color as 'geometryColor' and after return if 'geometryColor' has
* changed the op must override its geometry processor color output with the new color.
GrDrawOp::RequiresDstTexture xpRequiresDstTexture(const GrCaps&, const GrAppliedClip*,
GrProcessorAnalysisCoverage geometryCoverage,
GrColor* geometryColor);
bool usesLocalCoords() const {
return fUsesLocalCoords;
bool compatibleWithAlphaAsCoverage() const { return fCompatibleWithAlphaAsCoveage; }
GrPipeline* makePipeline(GrMeshDrawOp::Target* target) const {
return target->allocPipeline(this->pipelineInitArgs(target));
struct MakeArgs {
MakeArgs() = default;
GrProcessorSet* fProcessorSet;
uint32_t fSRGBFlags;
friend class GrSimpleMeshDrawOpHelper;
SkString dumpInfo() const;
GrAAType aaType() const { return static_cast<GrAAType>(fAAType); }
uint32_t pipelineFlags() const { return fPipelineFlags; }
const GrProcessorSet& processors() const {
return fProcessors ? *fProcessors : GrProcessorSet::EmptySet();
GrPipeline::InitArgs pipelineInitArgs(GrMeshDrawOp::Target* target) const;
GrProcessorSet* fProcessors;
unsigned fPipelineFlags : 8;
unsigned fAAType : 2;
unsigned fRequiresDstTexture : 1;
unsigned fUsesLocalCoords : 1;
unsigned fCompatibleWithAlphaAsCoveage : 1;
SkDEBUGCODE(unsigned fDidAnalysis : 1;)
* This class extends GrSimpleMeshDrawOpHelper to support an optional GrUserStencilSettings. This
* uses private inheritance because it non-virtually overrides methods in the base class and should
* never be used with a GrSimpleMeshDrawOpHelper pointer or reference.
class GrSimpleMeshDrawOpHelperWithStencil : private GrSimpleMeshDrawOpHelper {
using MakeArgs = GrSimpleMeshDrawOpHelper::MakeArgs;
using Flags = GrSimpleMeshDrawOpHelper::Flags;
// using declarations can't be templated, so this is a pass through function instead.
template <typename Op, typename... OpArgs>
static std::unique_ptr<GrDrawOp> FactoryHelper(GrPaint&& paint, OpArgs... opArgs) {
return GrSimpleMeshDrawOpHelper::FactoryHelper<Op, OpArgs...>(
std::move(paint), std::forward<OpArgs>(opArgs)...);
GrSimpleMeshDrawOpHelperWithStencil(const MakeArgs&, GrAAType, const GrUserStencilSettings*,
Flags = Flags::kNone);
GrDrawOp::FixedFunctionFlags fixedFunctionFlags() const;
using GrSimpleMeshDrawOpHelper::xpRequiresDstTexture;
using GrSimpleMeshDrawOpHelper::usesLocalCoords;
using GrSimpleMeshDrawOpHelper::compatibleWithAlphaAsCoverage;
bool isCompatible(const GrSimpleMeshDrawOpHelperWithStencil& that, const GrCaps&,
const SkRect& thisBounds, const SkRect& thatBounds) const;
const GrPipeline* makePipeline(GrMeshDrawOp::Target*) const;
SkString dumpInfo() const;
const GrUserStencilSettings* fStencilSettings;
typedef GrSimpleMeshDrawOpHelper INHERITED;
template <typename Op, typename... OpArgs>
std::unique_ptr<GrDrawOp> GrSimpleMeshDrawOpHelper::FactoryHelper(GrPaint&& paint,
OpArgs... opArgs) {
MakeArgs makeArgs;
makeArgs.fSRGBFlags = GrPipeline::SRGBFlagsFromPaint(paint);
GrColor color = paint.getColor();
if (paint.isTrivial()) {
makeArgs.fProcessorSet = nullptr;
return std::unique_ptr<GrDrawOp>(new Op(makeArgs, color, std::forward<OpArgs>(opArgs)...));
} else {
char* mem = (char*)GrOp::operator new(sizeof(Op) + sizeof(GrProcessorSet));
char* setMem = mem + sizeof(Op);
makeArgs.fProcessorSet = new (setMem) GrProcessorSet(std::move(paint));
return std::unique_ptr<GrDrawOp>(
new (mem) Op(makeArgs, color, std::forward<OpArgs>(opArgs)...));