1 /*
2 * Copyright 2017 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 "modules/skcms/skcms.h"
9 #include "src/core/SkRasterPipeline.h"
10 #include "src/core/SkRasterPipelineOpContexts.h"
11 #include "src/core/SkRasterPipelineOpList.h"
12 #include "tests/Test.h"
13
14 #include <cmath>
15
check_error(skiatest::Reporter * r,float limit,skcms_TransferFunction fn)16 static void check_error(skiatest::Reporter* r, float limit, skcms_TransferFunction fn) {
17 float in[256], out[256];
18 for (int i = 0; i < 256; i++) {
19 in [i] = i / 255.0f;
20 out[i] = 0.0f; // Not likely important. Just being tidy.
21 }
22
23 SkRasterPipeline_MemoryCtx ip = { in, 0},
24 op = {out, 0};
25
26 SkRasterPipeline_<256> p;
27 p.append(SkRasterPipelineOp::load_f32, &ip);
28 p.appendTransferFunction(fn);
29 p.append(SkRasterPipelineOp::store_f32, &op);
30
31 p.run(0,0, 256/4,1);
32
33
34 for (int i = 0; i < 256; i++) {
35 float want = (in[i] <= fn.d) ? fn.c * in[i] + fn.f
36 : powf(in[i] * fn.a + fn.b, fn.g) + fn.e;
37 if (i % 4 == 3) { // alpha should stay unchanged.
38 want = in[i];
39 }
40 float err = fabsf(out[i] - want);
41 if (err > limit) {
42 ERRORF(r, "At %d, error was %g (got %g, want %g)", i, err, out[i], want);
43 }
44 }
45 }
46
check_error(skiatest::Reporter * r,float limit,float gamma)47 static void check_error(skiatest::Reporter* r, float limit, float gamma) {
48 skcms_TransferFunction fn = {0,0,0,0,0,0,0};
49 fn.g = gamma;
50 fn.a = 1;
51 check_error(r, limit, fn);
52 }
53
DEF_TEST(Parametric_sRGB,r)54 DEF_TEST(Parametric_sRGB, r) {
55 // Test our good buddy the sRGB transfer function in resplendent 7-parameter glory.
56 check_error(r, 1/510.0f, {
57 2.4f,
58 1.0f / 1.055f,
59 0.055f / 1.055f,
60 1.0f / 12.92f,
61 0.04045f,
62 0.0f,
63 0.0f,
64 });
65 }
66
67 // A nice little spread of simple gammas.
DEF_TEST(Parametric_1dot0,r)68 DEF_TEST(Parametric_1dot0, r) { check_error(r, 1/510.0f, 1.0f); }
69
DEF_TEST(Parametric_1dot2,r)70 DEF_TEST(Parametric_1dot2, r) { check_error(r, 1/510.0f, 1.2f); }
DEF_TEST(Parametric_1dot4,r)71 DEF_TEST(Parametric_1dot4, r) { check_error(r, 1/510.0f, 1.4f); }
DEF_TEST(Parametric_1dot8,r)72 DEF_TEST(Parametric_1dot8, r) { check_error(r, 1/510.0f, 1.8f); }
DEF_TEST(Parametric_2dot0,r)73 DEF_TEST(Parametric_2dot0, r) { check_error(r, 1/510.0f, 2.0f); }
DEF_TEST(Parametric_2dot2,r)74 DEF_TEST(Parametric_2dot2, r) { check_error(r, 1/510.0f, 2.2f); }
DEF_TEST(Parametric_2dot4,r)75 DEF_TEST(Parametric_2dot4, r) { check_error(r, 1/510.0f, 2.4f); }
76
DEF_TEST(Parametric_inv_1dot2,r)77 DEF_TEST(Parametric_inv_1dot2, r) { check_error(r, 1/510.0f, 1/1.2f); }
DEF_TEST(Parametric_inv_1dot4,r)78 DEF_TEST(Parametric_inv_1dot4, r) { check_error(r, 1/510.0f, 1/1.4f); }
DEF_TEST(Parametric_inv_1dot8,r)79 DEF_TEST(Parametric_inv_1dot8, r) { check_error(r, 1/510.0f, 1/1.8f); }
DEF_TEST(Parametric_inv_2dot0,r)80 DEF_TEST(Parametric_inv_2dot0, r) { check_error(r, 1/510.0f, 1/2.0f); }
DEF_TEST(Parametric_inv_2dot2,r)81 DEF_TEST(Parametric_inv_2dot2, r) { check_error(r, 1/510.0f, 1/2.2f); }
DEF_TEST(Parametric_inv_2dot4,r)82 DEF_TEST(Parametric_inv_2dot4, r) { check_error(r, 1/510.0f, 1/2.4f); }
83