1 /*
2 * Copyright 2020 Google LLC
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 "tests/Test.h"
9
10 #include "src/gpu/GrFragmentProcessor.h"
11 #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
12 #include "src/gpu/v1/SurfaceDrawContext_v1.h"
13
14 static void run_test(skiatest::Reporter*, GrDirectContext*,
15 skgpu::v1::SurfaceDrawContext*, SkVector a,
16 SkVector b, float expectedCrossProduct);
17
18 // This is a GPU test that ensures the SkSL 2d cross() intrinsic returns the correct sign (negative,
19 // positive, or zero).
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SkSLCross,reporter,ctxInfo)20 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SkSLCross, reporter, ctxInfo) {
21 GrDirectContext* dContext = ctxInfo.directContext();
22 auto sdc = skgpu::v1::SurfaceDrawContext::Make(dContext, GrColorType::kRGBA_8888, nullptr,
23 SkBackingFit::kExact, {1, 1}, SkSurfaceProps());
24 if (!sdc) {
25 ERRORF(reporter, "could not create render target context.");
26 return;
27 }
28 run_test(reporter, dContext, sdc.get(), {3,4}, {5,6}, -2); // Negative.
29 run_test(reporter, dContext, sdc.get(), {3,4}, {-5,-6}, 2); // Positive.
30 run_test(reporter, dContext, sdc.get(), {0, 2.287f}, {0, -7.741f}, 0); // Zero.
31 run_test(reporter, dContext, sdc.get(), {62.17f, 0}, {-43.49f, 0}, 0); // Zero.
32 }
33
34 namespace {
35
36 // Outputs:
37 // Green if cross(a,b) > 0
38 // Red if cross(a,b) < 0
39 // Black if cross(a,b) == 0
40 class VisualizeCrossProductSignFP : public GrFragmentProcessor {
41 public:
VisualizeCrossProductSignFP(SkVector a,SkVector b)42 VisualizeCrossProductSignFP(SkVector a, SkVector b)
43 : GrFragmentProcessor(kTestFP_ClassID, kPreservesOpaqueInput_OptimizationFlag)
44 , fA(a), fB(b) {
45 }
46
name() const47 const char* name() const override { return "VisualizeCrossProductSignFP"; }
48
clone() const49 std::unique_ptr<GrFragmentProcessor> clone() const override {
50 return std::unique_ptr<GrFragmentProcessor>(new VisualizeCrossProductSignFP(fA, fB));
51 }
52
53 private:
onAddToKey(const GrShaderCaps &,GrProcessorKeyBuilder *) const54 void onAddToKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override {}
onIsEqual(const GrFragmentProcessor &) const55 bool onIsEqual(const GrFragmentProcessor&) const override { return true; }
56
onMakeProgramImpl() const57 std::unique_ptr<ProgramImpl> onMakeProgramImpl() const override {
58 class Impl : public ProgramImpl {
59 public:
60 void emitCode(EmitArgs& args) override {
61 auto& fp = args.fFp.cast<VisualizeCrossProductSignFP>();
62 const char *a, *b;
63 fAUniform = args.fUniformHandler->addUniform(&fp, kFragment_GrShaderFlag,
64 GrSLType::kFloat2_GrSLType, "a", &a);
65 fBUniform = args.fUniformHandler->addUniform(&fp, kFragment_GrShaderFlag,
66 GrSLType::kFloat2_GrSLType, "b", &b);
67 args.fFragBuilder->codeAppendf(R"(
68 float crossProduct = cross(%s, %s);
69 float2 visualization = clamp(float2(-sign(crossProduct), sign(crossProduct)),
70 float2(0), float2(1));
71 return half2(visualization).xy01;)", a, b);
72 }
73
74 private:
75 void onSetData(const GrGLSLProgramDataManager& pdman,
76 const GrFragmentProcessor& processor) override {
77 const auto& fp = processor.cast<VisualizeCrossProductSignFP>();
78 pdman.set2f(fAUniform, fp.fA.x(), fp.fA.y());
79 pdman.set2f(fBUniform, fp.fB.x(), fp.fB.y());
80 }
81 GrGLSLUniformHandler::UniformHandle fAUniform;
82 GrGLSLUniformHandler::UniformHandle fBUniform;
83 };
84
85 return std::make_unique<Impl>();
86 }
87 const SkVector fA, fB;
88 };
89
90 } // namespace
91
run_test(skiatest::Reporter * reporter,GrDirectContext * directContext,skgpu::v1::SurfaceDrawContext * sdc,SkVector a,SkVector b,float expectedCrossProduct)92 static void run_test(skiatest::Reporter* reporter, GrDirectContext* directContext,
93 skgpu::v1::SurfaceDrawContext* sdc, SkVector a, SkVector b,
94 float expectedCrossProduct) {
95 SkASSERT(sdc->width() == 1);
96 SkASSERT(sdc->height() == 1);
97
98 sdc->clear(SkPMColor4f::FromBytes_RGBA(0xbaaaaaad));
99
100 GrPaint crossPaint;
101 crossPaint.setColor4f(SK_PMColor4fWHITE);
102 crossPaint.setPorterDuffXPFactory(SkBlendMode::kSrcOver);
103 crossPaint.setColorFragmentProcessor(std::make_unique<VisualizeCrossProductSignFP>(a, b));
104 sdc->drawRect(/*clip=*/nullptr, std::move(crossPaint), GrAA::kNo, SkMatrix::I(),
105 SkRect::MakeWH(1,1));
106
107 GrColor result;
108 GrPixmap resultPM(SkImageInfo::Make(1, 1, kRGBA_8888_SkColorType, kPremul_SkAlphaType),
109 &result,
110 sizeof(GrColor));
111 sdc->readPixels(directContext, resultPM, {0, 0});
112
113 SkASSERT(expectedCrossProduct == a.cross(b));
114 if (expectedCrossProduct > 0) {
115 REPORTER_ASSERT(reporter, result == GrColorPackRGBA(0, 255, 0, 255)); // Green.
116 } else if (expectedCrossProduct < 0) {
117 REPORTER_ASSERT(reporter, result == GrColorPackRGBA(255, 0, 0, 255)); // Red.
118 } else {
119 REPORTER_ASSERT(reporter, result == GrColorPackRGBA(0, 0, 0, 255)); // Black.
120 }
121 }
122