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/GrSurfaceDrawContext.h"
11 #include "src/gpu/glsl/GrGLSLFragmentProcessor.h"
12
13 static void run_test(skiatest::Reporter*, GrDirectContext*,
14 GrSurfaceDrawContext*, SkVector a,
15 SkVector b, float expectedCrossProduct);
16
17 // This is a GPU test that ensures the SkSL 2d cross() intrinsic returns the correct sign (negative,
18 // positive, or zero).
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SkSLCross,reporter,ctxInfo)19 DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SkSLCross, reporter, ctxInfo) {
20 GrDirectContext* directContext = ctxInfo.directContext();
21 auto rtc = GrSurfaceDrawContext::Make(directContext, GrColorType::kRGBA_8888, nullptr,
22 SkBackingFit::kExact, {1, 1}, SkSurfaceProps());
23 if (!rtc) {
24 ERRORF(reporter, "could not create render target context.");
25 return;
26 }
27 run_test(reporter, directContext, rtc.get(), {3,4}, {5,6}, -2); // Negative.
28 run_test(reporter, directContext, rtc.get(), {3,4}, {-5,-6}, 2); // Positive.
29 run_test(reporter, directContext, rtc.get(), {0, 2.287f}, {0, -7.741f}, 0); // Zero.
30 run_test(reporter, directContext, rtc.get(), {62.17f, 0}, {-43.49f, 0}, 0); // Zero.
31 }
32
33 namespace {
34
35 // Outputs:
36 // Green if cross(a,b) > 0
37 // Red if cross(a,b) < 0
38 // Black if cross(a,b) == 0
39 class VisualizeCrossProductSignFP : public GrFragmentProcessor {
40 public:
VisualizeCrossProductSignFP(SkVector a,SkVector b)41 VisualizeCrossProductSignFP(SkVector a, SkVector b)
42 : GrFragmentProcessor(kTestFP_ClassID, kPreservesOpaqueInput_OptimizationFlag)
43 , fA(a), fB(b) {
44 }
45
46 private:
name() const47 const char* name() const override { return "VisualizeCrossProductSignFP"; }
clone() const48 std::unique_ptr<GrFragmentProcessor> clone() const override {
49 return std::unique_ptr<GrFragmentProcessor>(new VisualizeCrossProductSignFP(fA, fB));
50 }
onGetGLSLProcessorKey(const GrShaderCaps &,GrProcessorKeyBuilder *) const51 void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override {}
onIsEqual(const GrFragmentProcessor &) const52 bool onIsEqual(const GrFragmentProcessor&) const override { return true; }
53
54 class Impl : public GrGLSLFragmentProcessor {
emitCode(EmitArgs & args)55 void emitCode(EmitArgs& args) override {
56 auto& fp = args.fFp.cast<VisualizeCrossProductSignFP>();
57 const char* a, *b;
58 fAUniform = args.fUniformHandler->addUniform(&fp, kFragment_GrShaderFlag,
59 GrSLType::kFloat2_GrSLType, "a", &a);
60 fBUniform = args.fUniformHandler->addUniform(&fp, kFragment_GrShaderFlag,
61 GrSLType::kFloat2_GrSLType, "b", &b);
62 args.fFragBuilder->codeAppendf(R"(
63 float crossProduct = cross(%s, %s);
64 float2 visualization = clamp(float2(-sign(crossProduct), sign(crossProduct)),
65 float2(0), float2(1));
66 return half2(visualization).xy01;)", a, b);
67 }
onSetData(const GrGLSLProgramDataManager & pdman,const GrFragmentProcessor & processor)68 void onSetData(const GrGLSLProgramDataManager& pdman,
69 const GrFragmentProcessor& processor) override {
70 const auto& fp = processor.cast<VisualizeCrossProductSignFP>();
71 pdman.set2f(fAUniform, fp.fA.x(), fp.fA.y());
72 pdman.set2f(fBUniform, fp.fB.x(), fp.fB.y());
73 }
74 GrGLSLUniformHandler::UniformHandle fAUniform;
75 GrGLSLUniformHandler::UniformHandle fBUniform;
76 };
77
onMakeProgramImpl() const78 std::unique_ptr<GrGLSLFragmentProcessor> onMakeProgramImpl() const override {
79 return std::make_unique<Impl>();
80 }
81 const SkVector fA, fB;
82 };
83
84 } // namespace
85
run_test(skiatest::Reporter * reporter,GrDirectContext * directContext,GrSurfaceDrawContext * rtc,SkVector a,SkVector b,float expectedCrossProduct)86 static void run_test(skiatest::Reporter* reporter, GrDirectContext* directContext,
87 GrSurfaceDrawContext* rtc, SkVector a, SkVector b,
88 float expectedCrossProduct) {
89 SkASSERT(rtc->width() == 1);
90 SkASSERT(rtc->height() == 1);
91
92 rtc->clear(SkPMColor4f::FromBytes_RGBA(0xbaaaaaad));
93
94 GrPaint crossPaint;
95 crossPaint.setColor4f(SK_PMColor4fWHITE);
96 crossPaint.setPorterDuffXPFactory(SkBlendMode::kSrcOver);
97 crossPaint.setColorFragmentProcessor(std::make_unique<VisualizeCrossProductSignFP>(a, b));
98 rtc->drawRect(/*clip=*/nullptr, std::move(crossPaint), GrAA::kNo, SkMatrix::I(),
99 SkRect::MakeWH(1,1));
100
101 GrColor result;
102 GrPixmap resultPM(SkImageInfo::Make(1, 1, kRGBA_8888_SkColorType, kPremul_SkAlphaType),
103 &result,
104 sizeof(GrColor));
105 rtc->readPixels(directContext, resultPM, {0, 0});
106
107 SkASSERT(expectedCrossProduct == a.cross(b));
108 if (expectedCrossProduct > 0) {
109 REPORTER_ASSERT(reporter, result == GrColorPackRGBA(0, 255, 0, 255)); // Green.
110 } else if (expectedCrossProduct < 0) {
111 REPORTER_ASSERT(reporter, result == GrColorPackRGBA(255, 0, 0, 255)); // Red.
112 } else {
113 REPORTER_ASSERT(reporter, result == GrColorPackRGBA(0, 0, 0, 255)); // Black.
114 }
115 }
116