xref: /aosp_15_r20/external/skia/tests/NonlinearBlendingTest.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 "include/core/SkAlphaType.h"
9 #include "include/core/SkColor.h"
10 #include "include/core/SkColorSpace.h"
11 #include "include/core/SkRefCnt.h"
12 #include "modules/skcms/skcms.h"
13 #include "src/core/SkColorSpaceXformSteps.h"
14 #include "tests/Test.h"
15 
16 #include <cmath>
17 
DEF_TEST(SkColorSpaceXformSteps_vs_skcms,r)18 DEF_TEST(SkColorSpaceXformSteps_vs_skcms, r) {
19     auto srgb = SkColorSpace::MakeSRGB();
20     auto dp3  = SkColorSpace::MakeRGB(SkNamedTransferFn::kSRGB, SkNamedGamut::kDisplayP3);
21 
22     skcms_ICCProfile srgb_profile;
23     srgb->toProfile(&srgb_profile);
24     skcms_ICCProfile dp3_profile;
25     dp3->toProfile(&dp3_profile);
26 
27     // These colors provide a good spread of interesting test cases.
28     SkColor colors[] = {
29         0xffff0000, 0x7fff0000, 0x7f7f0000,
30         0xff00ff00, 0x7f00ff00, 0x7f007f00,
31     };
32 
33     for (auto color : colors) {
34         auto bgra = skcms_PixelFormat_BGRA_8888,
35               f32 = skcms_PixelFormat_RGBA_ffff;
36         auto unpremul = skcms_AlphaFormat_Unpremul,
37                premul = skcms_AlphaFormat_PremulAsEncoded;
38 
39         float via_skcms[4];
40         skcms_Transform(&color,     bgra, unpremul, &srgb_profile,
41                         &via_skcms,  f32,   premul,  &dp3_profile,
42                         1);
43 
44         SkColorSpaceXformSteps steps(srgb.get(), kUnpremul_SkAlphaType,
45                                       dp3.get(),   kPremul_SkAlphaType);
46         float via_steps[4] = {
47             SkColorGetR(color) * (1 / 255.0f),
48             SkColorGetG(color) * (1 / 255.0f),
49             SkColorGetB(color) * (1 / 255.0f),
50             SkColorGetA(color) * (1 / 255.0f),
51         };
52         steps.apply(via_steps);
53 
54         REPORTER_ASSERT(r, fabsf(via_skcms[0] - via_steps[0]) <= 0.005f);
55         REPORTER_ASSERT(r, fabsf(via_skcms[1] - via_steps[1]) <= 0.005f);
56         REPORTER_ASSERT(r, fabsf(via_skcms[2] - via_steps[2]) <= 0.005f);
57         REPORTER_ASSERT(r, fabsf(via_skcms[3] - via_steps[3]) <= 0.0f);
58 
59         // Now go back using the other method's inverse transform
60         float steps_to_skcms[4];
61         skcms_Transform(via_steps,      f32, premul, &dp3_profile,
62                         steps_to_skcms, f32, premul, &srgb_profile,
63                         1);
64 
65         float skcms_to_steps[4] = { via_skcms[0], via_skcms[1], via_skcms[2], via_skcms[3] };
66         SkColorSpaceXformSteps inv_steps(dp3.get(), kPremul_SkAlphaType,
67                                         srgb.get(), kPremul_SkAlphaType);
68         inv_steps.apply(skcms_to_steps);
69 
70         REPORTER_ASSERT(r, fabsf(skcms_to_steps[0] - steps_to_skcms[0]) <= 0.005f);
71         REPORTER_ASSERT(r, fabsf(skcms_to_steps[1] - steps_to_skcms[1]) <= 0.005f);
72         REPORTER_ASSERT(r, fabsf(skcms_to_steps[2] - steps_to_skcms[2]) <= 0.005f);
73         REPORTER_ASSERT(r, fabsf(skcms_to_steps[3] - steps_to_skcms[3]) <= 0.0f);
74     }
75 }
76