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