1 /*
2  * Copyright 2018 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 #include "gm.h"
9 
10 #include "GrClip.h"
11 #include "GrContext.h"
12 #include "GrGpuCommandBuffer.h"
13 #include "GrMemoryPool.h"
14 #include "GrOpFlushState.h"
15 #include "GrRenderTargetContext.h"
16 #include "GrRenderTargetContextPriv.h"
17 #include "GrRenderTarget.h"
18 #include "glsl/GrGLSLFragmentShaderBuilder.h"
19 #include "glsl/GrGLSLGeometryProcessor.h"
20 #include "glsl/GrGLSLVarying.h"
21 #include "glsl/GrGLSLVertexGeoBuilder.h"
22 
23 namespace skiagm {
24 
25 static constexpr GrGeometryProcessor::Attribute gVertex =
26         {"vertex", kFloat2_GrVertexAttribType, kFloat2_GrSLType};
27 
28 /**
29  * This is a GPU-backend specific test. It ensures that SkSL properly identifies clockwise-winding
30  * triangles (sk_Clockwise), in terms of to Skia device space, in all backends and with all render
31  * target origins. We draw clockwise triangles green and counter-clockwise red.
32  */
33 class ClockwiseGM : public GM {
34 private:
onShortName()35     SkString onShortName() final { return SkString("clockwise"); }
onISize()36     SkISize onISize() override { return SkISize::Make(300, 200); }
37     void onDraw(SkCanvas*) override;
38 };
39 
40 ////////////////////////////////////////////////////////////////////////////////////////////////////
41 // SkSL code.
42 
43 class ClockwiseTestProcessor : public GrGeometryProcessor {
44 public:
ClockwiseTestProcessor(bool readSkFragCoord)45     ClockwiseTestProcessor(bool readSkFragCoord)
46             : GrGeometryProcessor(kClockwiseTestProcessor_ClassID)
47             , fReadSkFragCoord(readSkFragCoord) {
48         this->setVertexAttributes(&gVertex, 1);
49     }
name() const50     const char* name() const override { return "ClockwiseTestProcessor"; }
getGLSLProcessorKey(const GrShaderCaps &,GrProcessorKeyBuilder * b) const51     void getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder* b) const final {
52         b->add32(fReadSkFragCoord);
53     }
54     GrGLSLPrimitiveProcessor* createGLSLInstance(const GrShaderCaps&) const final;
55 
56 private:
57     const bool fReadSkFragCoord;
58 
59     friend class GLSLClockwiseTestProcessor;
60 };
61 
62 class GLSLClockwiseTestProcessor : public GrGLSLGeometryProcessor {
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor &,FPCoordTransformIter && transformIter)63     void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor&,
64                  FPCoordTransformIter&& transformIter) override {}
65 
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)66     void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
67         const ClockwiseTestProcessor& proc = args.fGP.cast<ClockwiseTestProcessor>();
68         args.fVaryingHandler->emitAttributes(proc);
69         gpArgs->fPositionVar.set(kFloat2_GrSLType, "vertex");
70         args.fFragBuilder->codeAppendf(
71                 "%s = sk_Clockwise ? half4(0,1,0,1) : half4(1,0,0,1);", args.fOutputColor);
72         if (!proc.fReadSkFragCoord) {
73             args.fFragBuilder->codeAppendf("%s = half4(1);", args.fOutputCoverage);
74         } else {
75             // Verify layout(origin_upper_left) on gl_FragCoord does not affect gl_FrontFacing.
76             args.fFragBuilder->codeAppendf("%s = half4(min(sk_FragCoord.y, 1));",
77                                            args.fOutputCoverage);
78         }
79     }
80 };
81 
createGLSLInstance(const GrShaderCaps &) const82 GrGLSLPrimitiveProcessor* ClockwiseTestProcessor::createGLSLInstance(
83         const GrShaderCaps&) const {
84     return new GLSLClockwiseTestProcessor;
85 }
86 
87 ////////////////////////////////////////////////////////////////////////////////////////////////////
88 // Draw Op.
89 
90 class ClockwiseTestOp : public GrDrawOp {
91 public:
92     DEFINE_OP_CLASS_ID
93 
Make(GrContext * context,bool readSkFragCoord,int y=0)94     static std::unique_ptr<GrDrawOp> Make(GrContext* context, bool readSkFragCoord, int y = 0) {
95         GrOpMemoryPool* pool = context->contextPriv().opMemoryPool();
96         return pool->allocate<ClockwiseTestOp>(readSkFragCoord, y);
97     }
98 
99 private:
ClockwiseTestOp(bool readSkFragCoord,float y)100     ClockwiseTestOp(bool readSkFragCoord, float y)
101             : GrDrawOp(ClassID()), fReadSkFragCoord(readSkFragCoord), fY(y) {
102         this->setBounds(SkRect::MakeIWH(300, 100), HasAABloat::kNo, IsZeroArea::kNo);
103     }
104 
name() const105     const char* name() const override { return "ClockwiseTestOp"; }
fixedFunctionFlags() const106     FixedFunctionFlags fixedFunctionFlags() const override { return FixedFunctionFlags::kNone; }
finalize(const GrCaps &,const GrAppliedClip *)107     GrProcessorSet::Analysis finalize(const GrCaps&, const GrAppliedClip*) override {
108         return GrProcessorSet::EmptySetAnalysis();
109     }
onPrepare(GrOpFlushState *)110     void onPrepare(GrOpFlushState*) override {}
onExecute(GrOpFlushState * flushState,const SkRect & chainBounds)111     void onExecute(GrOpFlushState* flushState, const SkRect& chainBounds) override {
112         SkPoint vertices[4] = {
113             {100, fY},
114             {0, fY+100},
115             {0, fY},
116             {100, fY+100},
117         };
118         sk_sp<const GrBuffer> vertexBuffer(flushState->resourceProvider()->createBuffer(
119                 sizeof(vertices), kVertex_GrBufferType, kStatic_GrAccessPattern,
120                 GrResourceProvider::Flags::kNone, vertices));
121         if (!vertexBuffer) {
122             return;
123         }
124         GrPipeline pipeline(GrScissorTest::kDisabled, SkBlendMode::kPlus);
125         GrMesh mesh(GrPrimitiveType::kTriangleStrip);
126         mesh.setNonIndexedNonInstanced(4);
127         mesh.setVertexData(std::move(vertexBuffer));
128         flushState->rtCommandBuffer()->draw(ClockwiseTestProcessor(fReadSkFragCoord), pipeline,
129                                             nullptr, nullptr, &mesh, 1, SkRect::MakeIWH(100, 100));
130     }
131 
132     const bool fReadSkFragCoord;
133     const float fY;
134 
135     friend class ::GrOpMemoryPool; // for ctor
136 };
137 
138 ////////////////////////////////////////////////////////////////////////////////////////////////////
139 // Test.
140 
onDraw(SkCanvas * canvas)141 void ClockwiseGM::onDraw(SkCanvas* canvas) {
142     GrContext* ctx = canvas->getGrContext();
143     GrRenderTargetContext* rtc = canvas->internal_private_accessTopLayerRenderTargetContext();
144     if (!ctx || !rtc) {
145         DrawGpuOnlyMessage(canvas);
146         return;
147     }
148 
149     rtc->clear(nullptr, { 0, 0, 0, 1 }, GrRenderTargetContext::CanClearFullscreen::kYes);
150 
151     // Draw the test directly to the frame buffer.
152     rtc->priv().testingOnly_addDrawOp(ClockwiseTestOp::Make(ctx, false, 0));
153     rtc->priv().testingOnly_addDrawOp(ClockwiseTestOp::Make(ctx, true, 100));
154 
155     // Draw the test to an off-screen, top-down render target.
156     if (auto topLeftRTC = ctx->contextPriv().makeDeferredRenderTargetContext(
157             rtc->asSurfaceProxy()->backendFormat(), SkBackingFit::kExact, 100, 200,
158             rtc->asSurfaceProxy()->config(), nullptr, 1, GrMipMapped::kNo,
159             kTopLeft_GrSurfaceOrigin, nullptr, SkBudgeted::kYes)) {
160         topLeftRTC->clear(nullptr, SK_PMColor4fTRANSPARENT,
161                           GrRenderTargetContext::CanClearFullscreen::kYes);
162         topLeftRTC->priv().testingOnly_addDrawOp(ClockwiseTestOp::Make(ctx, false, 0));
163         topLeftRTC->priv().testingOnly_addDrawOp(ClockwiseTestOp::Make(ctx, true, 100));
164         rtc->drawTexture(GrNoClip(), sk_ref_sp(topLeftRTC->asTextureProxy()),
165                          GrSamplerState::Filter::kNearest, SK_PMColor4fWHITE, {0, 0, 100, 200},
166                          {100, 0, 200, 200}, GrQuadAAFlags::kNone,
167                          SkCanvas::SrcRectConstraint::kStrict_SrcRectConstraint, SkMatrix::I(),
168                          nullptr);
169     }
170 
171     // Draw the test to an off-screen, bottom-up render target.
172     if (auto topLeftRTC = ctx->contextPriv().makeDeferredRenderTargetContext(
173             rtc->asSurfaceProxy()->backendFormat(), SkBackingFit::kExact, 100, 200,
174             rtc->asSurfaceProxy()->config(), nullptr, 1, GrMipMapped::kNo,
175             kBottomLeft_GrSurfaceOrigin, nullptr, SkBudgeted::kYes)) {
176         topLeftRTC->clear(nullptr, SK_PMColor4fTRANSPARENT,
177                           GrRenderTargetContext::CanClearFullscreen::kYes);
178         topLeftRTC->priv().testingOnly_addDrawOp(ClockwiseTestOp::Make(ctx, false, 0));
179         topLeftRTC->priv().testingOnly_addDrawOp(ClockwiseTestOp::Make(ctx, true, 100));
180         rtc->drawTexture(GrNoClip(), sk_ref_sp(topLeftRTC->asTextureProxy()),
181                          GrSamplerState::Filter::kNearest, SK_PMColor4fWHITE, {0, 0, 100, 200},
182                          {200, 0, 300, 200}, GrQuadAAFlags::kNone,
183                          SkCanvas::SrcRectConstraint::kStrict_SrcRectConstraint, SkMatrix::I(),
184                          nullptr);
185     }
186 }
187 
188 ////////////////////////////////////////////////////////////////////////////////////////////////////
189 
190 DEF_GM( return new ClockwiseGM(); )
191 
192 }
193