/* * Copyright 2018 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "SkColorSpacePriv.h" #include "SkColorSpaceXformSteps.h" #include "Test.h" template static void check_eq(skiatest::Reporter* r, SkColorSpaceXformSteps steps, T baseline) { REPORTER_ASSERT(r, steps.early_unpremul == baseline.early_unpremul); REPORTER_ASSERT(r, steps.linearize_src == baseline.linearize_src); REPORTER_ASSERT(r, steps.late_unpremul == baseline.late_unpremul); REPORTER_ASSERT(r, steps.gamut_transform == baseline.gamut_transform); REPORTER_ASSERT(r, steps.early_encode == baseline.early_encode); REPORTER_ASSERT(r, steps.premul == baseline.premul); REPORTER_ASSERT(r, steps.linearize_dst == baseline.linearize_dst); REPORTER_ASSERT(r, steps.late_encode == baseline.late_encode); // A couple (redundant) sanity checks that cover impossible states. // At most one of the early/late options should happen, possibly neither. REPORTER_ASSERT(r, !(steps.early_unpremul && steps.late_unpremul)); REPORTER_ASSERT(r, !(steps.early_encode && steps.late_encode)); } DEF_TEST(SkColorSpaceXformSteps, r) { auto srgb_L = SkColorSpace::MakeSRGB(), adobe_L = SkColorSpace::MakeRGB(g2Dot2_TransferFn, SkColorSpace::kAdobeRGB_Gamut), srgb22_L = SkColorSpace::MakeRGB(g2Dot2_TransferFn, SkColorSpace:: kSRGB_Gamut), srgb_N = srgb_L->makeNonlinearBlending(), adobe_N = adobe_L->makeNonlinearBlending(), srgb22_N = srgb22_L->makeNonlinearBlending(); struct { sk_sp src, dst; bool early_unpremul; bool linearize_src; bool late_unpremul; bool gamut_transform; bool early_encode; bool premul; bool linearize_dst; bool late_encode; } tests[] = { // The first eight cases we test are back and forth between two color spaces with // different gamuts and transfer functions. There's not much optimization possible here. { adobe_N, srgb_N, true, // src is encoded as f(s)*a,a, so we unpremul to f(s),a before linearizing. true, // Linearize to s,a. false, true, // Gamut transform. true, // Non-linear blending, so we encode to sRGB g(s),a early. true, // Premul to g(s)*a,a false, // Non-linear blending, so no need to linearize dst. false, // Non-linear blending, so the output of our blend function is what we want. }, { srgb_N, adobe_N, true,true,false, true,true,true, false,false }, { adobe_L, srgb_L, false, // src is encoded as f(s*a),a, so we linearize before unpremul. true, // Linearize, true, // then unpremul. true, // Gamut transform. false, // We're doing linear blending, so we don't encode to sRGB yet. true, // Premul so we can blend. true, // We're doing linear blending, so we need to linearize dst. true, // Once blending is done, finally encode to sRGB. }, { srgb_L, adobe_L, false,true,true, true,false,true, true,true }, { adobe_L, srgb_N, false, // src is encoded as f(s*a),a, so we linearize before unpremul. true, // Linearize, true, // then unpremul. true, // Gamut transform true, // We're doing non-linear blending, so encode to sRGB now. true, // (non-linear) premul false, // We're doing non-linear blending, so dst is already ready to blend. false, // The output of the blend is just what we want. }, { srgb_L, adobe_N, false,true,true, true,true,true, false,false }, { adobe_N, srgb_L, true, // src is encoded as f(s)*a,a, so we unpremul to f(s),a before linearizing. true, // Linearize to s,a. false, true, // Gamut transform false, // We're doing linear blending, so we don't encode to sRGB yet. true, // (linear) premul true, // We're doing linear blending, so we need to linearize dst. true, // Once blending is done, finally encode to sRGB. }, { srgb_N, adobe_L, true,true,false, true,false,true, true,true }, // These eight cases transform between color spaces with different // transfer functions and the same gamut. Optimization here is limited // to skipping the gamut_transform step: | // v This column has all become false. { srgb_N, srgb22_N, true,true,false, false,true,true, false,false }, { srgb22_N, srgb_N, true,true,false, false,true,true, false,false }, { srgb_L, srgb22_L, false,true,true, false,false,true, true,true }, { srgb22_L, srgb_L, false,true,true, false,false,true, true,true }, { srgb_N, srgb22_L, true,true,false, false,false,true, true,true }, { srgb22_N, srgb_L, true,true,false, false,false,true, true,true }, { srgb_L, srgb22_N, false,true,true, false,true,true, false,false }, { srgb22_L, srgb_N, false,true,true, false,true,true, false,false }, // These four test cases test drawing in the same color space. // There is lots of room for optimization here. { srgb_N, srgb_N, true,true,false, false,true,true, false,false }, // a.k.a legacy 8888 { srgb_L, srgb_L, false,true,true, false,false,true, true,true }, // use case { srgb_N, srgb_L, true,true,false, false,false,true, true,true }, { srgb_L, srgb_N, false,true,true, false,true,true, false,false }, // TODO: versions of above crossing in linear transfer functions }; for (auto t : tests) { // Our expectations are written for premul source alpha types. check_eq(r, SkColorSpaceXformSteps(t.src.get(), kPremul_SkAlphaType, t.dst.get()), t); // Opaque and unpremul sources should always go through the same steps, // and they should be the same as premul's steps, with these fixed premul/unpremul steps. auto upm = t; upm.early_unpremul = false; upm.late_unpremul = false; upm.premul = true; check_eq(r, SkColorSpaceXformSteps(t.src.get(), kUnpremul_SkAlphaType, t.dst.get()), upm); check_eq(r, SkColorSpaceXformSteps(t.src.get(), kOpaque_SkAlphaType, t.dst.get()), upm); } }