/* * Copyright 2016 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "SkColorSpaceXformSteps.h" #include "SkRasterPipeline.h" #include "SkTypes.h" #include "Test.h" #include <math.h> DEF_TEST(srgb_roundtrip, r) { for (int normalized = 0; normalized < 2; normalized++) { uint32_t reds[256]; for (int i = 0; i < 256; i++) { reds[i] = i; } SkRasterPipeline_MemoryCtx ptr = { reds, 0 }; sk_sp<SkColorSpace> sRGB = SkColorSpace::MakeSRGB(), linear = sRGB->makeLinearGamma(); const SkAlphaType upm = kUnpremul_SkAlphaType; SkColorSpaceXformSteps linearize{ sRGB.get(),upm, linear.get(),upm}, reencode {linear.get(),upm, sRGB.get(),upm}; SkRasterPipeline_<256> p; p.append(SkRasterPipeline::load_8888, &ptr); linearize.apply(&p, !!normalized); reencode .apply(&p, !!normalized); p.append(SkRasterPipeline::store_8888, &ptr); p.run(0,0,256,1); for (int i = 0; i < 256; i++) { if (reds[i] != (uint32_t)i) { ERRORF(r, "%d doesn't round trip, %d", i, reds[i]); } } } } DEF_TEST(srgb_edge_cases, r) { // We need to run at least 4 pixels to make sure we hit all specializations. float colors[4][4] = { {0,1,1,1}, {0,0,0,0}, {0,0,0,0}, {0,0,0,0} }; auto& color = colors[0]; SkRasterPipeline_MemoryCtx dst = { &color, 0 }; sk_sp<SkColorSpace> sRGB = SkColorSpace::MakeSRGB(), linear = sRGB->makeLinearGamma(); const SkAlphaType upm = kUnpremul_SkAlphaType; SkColorSpaceXformSteps steps {linear.get(),upm, sRGB.get(),upm}; SkSTArenaAlloc<256> alloc; SkRasterPipeline p(&alloc); p.append_constant_color(&alloc, color); steps.apply(&p, true/*inputs are normalized*/); p.append(SkRasterPipeline::store_f32, &dst); p.run(0,0,4,1); if (color[0] != 0.0f) { ERRORF(r, "expected to_srgb() to map 0.0f to 0.0f, got %f", color[0]); } if (color[1] != 1.0f) { float f = color[1]; uint32_t x; memcpy(&x, &f, 4); ERRORF(r, "expected to_srgb() to map 1.0f to 1.0f, got %f (%08x)", color[1], x); } } // Linearize and then re-encode pixel values, testing that the output is close to the input. static void test_roundtripping(skiatest::Reporter* r, sk_sp<SkColorSpace> cs, float range, float tolerance, bool normalized) { static const int kSteps = 128; SkColor4f rgba[kSteps]; auto expected = [=](int i) { float scale = range / (3*kSteps); return SkColor4f{ (3*i+0) * scale, (3*i+1) * scale, (3*i+2) * scale, 1.0f, }; }; for (int i = 0; i < kSteps; i++) { rgba[i] = expected(i); } SkRasterPipeline_MemoryCtx ptr = { rgba, 0 }; sk_sp<SkColorSpace> linear = cs->makeLinearGamma(); const SkAlphaType upm = kUnpremul_SkAlphaType; SkColorSpaceXformSteps linearize{ cs.get(),upm, linear.get(),upm}, reencode {linear.get(),upm, cs.get(),upm}; SkRasterPipeline_<256> p; p.append(SkRasterPipeline::load_f32, &ptr); linearize.apply(&p, normalized); reencode .apply(&p, normalized); p.append(SkRasterPipeline::store_f32, &ptr); p.run(0,0,kSteps,1); auto close = [=](float x, float y) { return x == y || (x/y < tolerance && y/x < tolerance); }; for (int i = 0; i < kSteps; i++) { SkColor4f want = expected(i); #if 0 SkDebugf("got %g %g %g, want %g %g %g\n", rgba[i].fR, rgba[i].fG, rgba[i].fB, want.fR, want.fG, want.fB); #endif REPORTER_ASSERT(r, close(rgba[i].fR, want.fR)); REPORTER_ASSERT(r, close(rgba[i].fG, want.fG)); REPORTER_ASSERT(r, close(rgba[i].fB, want.fB)); } } DEF_TEST(srgb_roundtrip_extended, r) { // We're lying when we set normalized=true, but it allows us to test the to_srgb/from_srgb path. test_roundtripping(r, SkColorSpace::MakeSRGB(), 2.0f, 1.025f, true); // This normalized=false path should have much better round-tripping properties. test_roundtripping(r, SkColorSpace::MakeSRGB(), 10000.0f, 1.001f, false); }