1 /*
2 * Copyright 2017 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #ifndef GrSimpleMeshDrawOpHelper_DEFINED
9 #define GrSimpleMeshDrawOpHelper_DEFINED
10
11 #include "GrMeshDrawOp.h"
12 #include "GrOpFlushState.h"
13 #include "GrPipeline.h"
14
15 struct SkRect;
16
17 /**
18 * This class can be used to help implement simple mesh draw ops. It reduces the amount of
19 * boilerplate code to type and also provides a mechanism for optionally allocating space for a
20 * GrProcessorSet based on a GrPaint. It is intended to be used by ops that construct a single
21 * GrPipeline for a uniform primitive color and a GrPaint.
22 */
23 class GrSimpleMeshDrawOpHelper {
24 public:
25 struct MakeArgs;
26
27 /**
28 * This can be used by a Op class to perform allocation and initialization such that a
29 * GrProcessorSet (if required) is allocated as part of the the same allocation that as
30 * the Op instance. It requires that Op implements a constructor of the form:
31 * Op(MakeArgs, GrColor, OpArgs...)
32 * which is public or made accessible via 'friend'.
33 */
34 template <typename Op, typename... OpArgs>
35 static std::unique_ptr<GrDrawOp> FactoryHelper(GrPaint&& paint, OpArgs... opArgs);
36
37 enum class Flags : uint32_t {
38 kNone = 0x0,
39 kSnapVerticesToPixelCenters = 0x1,
40 };
41 GR_DECL_BITFIELD_CLASS_OPS_FRIENDS(Flags);
42
43 GrSimpleMeshDrawOpHelper(const MakeArgs&, GrAAType, Flags = Flags::kNone);
44 ~GrSimpleMeshDrawOpHelper();
45
46 GrSimpleMeshDrawOpHelper() = delete;
47 GrSimpleMeshDrawOpHelper(const GrSimpleMeshDrawOpHelper&) = delete;
48 GrSimpleMeshDrawOpHelper& operator=(const GrSimpleMeshDrawOpHelper&) = delete;
49
50 GrDrawOp::FixedFunctionFlags fixedFunctionFlags() const;
51
52 bool isCompatible(const GrSimpleMeshDrawOpHelper& that, const GrCaps&, const SkRect& thisBounds,
53 const SkRect& thatBounds) const;
54
55 /**
56 * Finalizes the processor set and determines whether the destination must be provided
57 * to the fragment shader as a texture for blending.
58 *
59 * @param geometryCoverage Describes the coverage output of the op's geometry processor
60 * @param geometryColor An in/out param. As input this informs processor analysis about the
61 * color the op expects to output from its geometry processor. As output
62 * this may be set to a known color in which case the op must output this
63 * color from its geometry processor instead.
64 */
65 GrDrawOp::RequiresDstTexture xpRequiresDstTexture(const GrCaps& caps, const GrAppliedClip* clip,
66 GrProcessorAnalysisCoverage geometryCoverage,
67 GrProcessorAnalysisColor* geometryColor);
68
69 /**
70 * Version of above that can be used by ops that have a constant color geometry processor
71 * output. The op passes this color as 'geometryColor' and after return if 'geometryColor' has
72 * changed the op must override its geometry processor color output with the new color.
73 */
74 GrDrawOp::RequiresDstTexture xpRequiresDstTexture(const GrCaps&, const GrAppliedClip*,
75 GrProcessorAnalysisCoverage geometryCoverage,
76 GrColor* geometryColor);
77
usesLocalCoords()78 bool usesLocalCoords() const {
79 SkASSERT(fDidAnalysis);
80 return fUsesLocalCoords;
81 }
82
compatibleWithAlphaAsCoverage()83 bool compatibleWithAlphaAsCoverage() const { return fCompatibleWithAlphaAsCoveage; }
84
makePipeline(GrMeshDrawOp::Target * target)85 GrPipeline* makePipeline(GrMeshDrawOp::Target* target) const {
86 return target->allocPipeline(this->pipelineInitArgs(target));
87 }
88
89 struct MakeArgs {
90 private:
91 MakeArgs() = default;
92
93 GrProcessorSet* fProcessorSet;
94 uint32_t fSRGBFlags;
95
96 friend class GrSimpleMeshDrawOpHelper;
97 };
98
99 SkString dumpInfo() const;
100
101 protected:
aaType()102 GrAAType aaType() const { return static_cast<GrAAType>(fAAType); }
pipelineFlags()103 uint32_t pipelineFlags() const { return fPipelineFlags; }
processors()104 const GrProcessorSet& processors() const {
105 return fProcessors ? *fProcessors : GrProcessorSet::EmptySet();
106 }
107
108 GrPipeline::InitArgs pipelineInitArgs(GrMeshDrawOp::Target* target) const;
109
110 private:
111 GrProcessorSet* fProcessors;
112 unsigned fPipelineFlags : 8;
113 unsigned fAAType : 2;
114 unsigned fRequiresDstTexture : 1;
115 unsigned fUsesLocalCoords : 1;
116 unsigned fCompatibleWithAlphaAsCoveage : 1;
117 SkDEBUGCODE(unsigned fDidAnalysis : 1;)
118 };
119
120 /**
121 * This class extends GrSimpleMeshDrawOpHelper to support an optional GrUserStencilSettings. This
122 * uses private inheritance because it non-virtually overrides methods in the base class and should
123 * never be used with a GrSimpleMeshDrawOpHelper pointer or reference.
124 */
125 class GrSimpleMeshDrawOpHelperWithStencil : private GrSimpleMeshDrawOpHelper {
126 public:
127 using MakeArgs = GrSimpleMeshDrawOpHelper::MakeArgs;
128 using Flags = GrSimpleMeshDrawOpHelper::Flags;
129
130 // using declarations can't be templated, so this is a pass through function instead.
131 template <typename Op, typename... OpArgs>
FactoryHelper(GrPaint && paint,OpArgs...opArgs)132 static std::unique_ptr<GrDrawOp> FactoryHelper(GrPaint&& paint, OpArgs... opArgs) {
133 return GrSimpleMeshDrawOpHelper::FactoryHelper<Op, OpArgs...>(
134 std::move(paint), std::forward<OpArgs>(opArgs)...);
135 }
136
137 GrSimpleMeshDrawOpHelperWithStencil(const MakeArgs&, GrAAType, const GrUserStencilSettings*,
138 Flags = Flags::kNone);
139
140 GrDrawOp::FixedFunctionFlags fixedFunctionFlags() const;
141
142 using GrSimpleMeshDrawOpHelper::xpRequiresDstTexture;
143 using GrSimpleMeshDrawOpHelper::usesLocalCoords;
144 using GrSimpleMeshDrawOpHelper::compatibleWithAlphaAsCoverage;
145
146 bool isCompatible(const GrSimpleMeshDrawOpHelperWithStencil& that, const GrCaps&,
147 const SkRect& thisBounds, const SkRect& thatBounds) const;
148
149 const GrPipeline* makePipeline(GrMeshDrawOp::Target*) const;
150
151 SkString dumpInfo() const;
152
153 private:
154 const GrUserStencilSettings* fStencilSettings;
155 typedef GrSimpleMeshDrawOpHelper INHERITED;
156 };
157
158 template <typename Op, typename... OpArgs>
FactoryHelper(GrPaint && paint,OpArgs...opArgs)159 std::unique_ptr<GrDrawOp> GrSimpleMeshDrawOpHelper::FactoryHelper(GrPaint&& paint,
160 OpArgs... opArgs) {
161 MakeArgs makeArgs;
162 makeArgs.fSRGBFlags = GrPipeline::SRGBFlagsFromPaint(paint);
163 GrColor color = paint.getColor();
164 if (paint.isTrivial()) {
165 makeArgs.fProcessorSet = nullptr;
166 return std::unique_ptr<GrDrawOp>(new Op(makeArgs, color, std::forward<OpArgs>(opArgs)...));
167 } else {
168 char* mem = (char*)GrOp::operator new(sizeof(Op) + sizeof(GrProcessorSet));
169 char* setMem = mem + sizeof(Op);
170 makeArgs.fProcessorSet = new (setMem) GrProcessorSet(std::move(paint));
171 return std::unique_ptr<GrDrawOp>(
172 new (mem) Op(makeArgs, color, std::forward<OpArgs>(opArgs)...));
173 }
174 }
175
176 GR_MAKE_BITFIELD_CLASS_OPS(GrSimpleMeshDrawOpHelper::Flags)
177
178 #endif
179