1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "Color.h"
18
19
20 #include <utils/Log.h>
21 #include <cmath>
22
23 namespace android {
24 namespace uirenderer {
25
almostEqual(float a,float b)26 static inline bool almostEqual(float a, float b) {
27 return std::abs(a - b) < 1e-2f;
28 }
29
transferFunctionCloseToSRGB(const SkColorSpace * colorSpace)30 bool transferFunctionCloseToSRGB(const SkColorSpace* colorSpace) {
31 if (colorSpace == nullptr) return true;
32 if (colorSpace->isSRGB()) return true;
33
34 SkColorSpaceTransferFn transferFunction;
35 if (colorSpace->isNumericalTransferFn(&transferFunction)) {
36 // sRGB transfer function params:
37 const float sRGBParamA = 1 / 1.055f;
38 const float sRGBParamB = 0.055f / 1.055f;
39 const float sRGBParamC = 1 / 12.92f;
40 const float sRGBParamD = 0.04045f;
41 const float sRGBParamE = 0.0f;
42 const float sRGBParamF = 0.0f;
43 const float sRGBParamG = 2.4f;
44
45 // This comparison will catch Display P3
46 return almostEqual(sRGBParamA, transferFunction.fA) &&
47 almostEqual(sRGBParamB, transferFunction.fB) &&
48 almostEqual(sRGBParamC, transferFunction.fC) &&
49 almostEqual(sRGBParamD, transferFunction.fD) &&
50 almostEqual(sRGBParamE, transferFunction.fE) &&
51 almostEqual(sRGBParamF, transferFunction.fF) &&
52 almostEqual(sRGBParamG, transferFunction.fG);
53 }
54
55 return false;
56 }
57
DataSpaceToColorSpace(android_dataspace dataspace)58 sk_sp<SkColorSpace> DataSpaceToColorSpace(android_dataspace dataspace) {
59
60 SkColorSpace::Gamut gamut;
61 switch (dataspace & HAL_DATASPACE_STANDARD_MASK) {
62 case HAL_DATASPACE_STANDARD_BT709:
63 gamut = SkColorSpace::kSRGB_Gamut;
64 break;
65 case HAL_DATASPACE_STANDARD_BT2020:
66 gamut = SkColorSpace::kRec2020_Gamut;
67 break;
68 case HAL_DATASPACE_STANDARD_DCI_P3:
69 gamut = SkColorSpace::kDCIP3_D65_Gamut;
70 break;
71 case HAL_DATASPACE_STANDARD_ADOBE_RGB:
72 gamut = SkColorSpace::kAdobeRGB_Gamut;
73 break;
74 case HAL_DATASPACE_STANDARD_UNSPECIFIED:
75 return nullptr;
76 case HAL_DATASPACE_STANDARD_BT601_625:
77 case HAL_DATASPACE_STANDARD_BT601_625_UNADJUSTED:
78 case HAL_DATASPACE_STANDARD_BT601_525:
79 case HAL_DATASPACE_STANDARD_BT601_525_UNADJUSTED:
80 case HAL_DATASPACE_STANDARD_BT2020_CONSTANT_LUMINANCE:
81 case HAL_DATASPACE_STANDARD_BT470M:
82 case HAL_DATASPACE_STANDARD_FILM:
83 default:
84 ALOGW("Unsupported Gamut: %d", dataspace);
85 return nullptr;
86 }
87
88 switch (dataspace & HAL_DATASPACE_TRANSFER_MASK) {
89 case HAL_DATASPACE_TRANSFER_LINEAR:
90 return SkColorSpace::MakeRGB(SkColorSpace::kLinear_RenderTargetGamma, gamut);
91 case HAL_DATASPACE_TRANSFER_SRGB:
92 return SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma, gamut);
93 case HAL_DATASPACE_TRANSFER_GAMMA2_2:
94 return SkColorSpace::MakeRGB({2.2f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f}, gamut);
95 case HAL_DATASPACE_TRANSFER_GAMMA2_6:
96 return SkColorSpace::MakeRGB({2.6f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f}, gamut);
97 case HAL_DATASPACE_TRANSFER_GAMMA2_8:
98 return SkColorSpace::MakeRGB({2.8f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f}, gamut);
99 case HAL_DATASPACE_TRANSFER_UNSPECIFIED:
100 return nullptr;
101 case HAL_DATASPACE_TRANSFER_SMPTE_170M:
102 case HAL_DATASPACE_TRANSFER_ST2084:
103 case HAL_DATASPACE_TRANSFER_HLG:
104 default:
105 ALOGW("Unsupported Gamma: %d", dataspace);
106 return nullptr;
107 }
108 }
109
110 }; // namespace uirenderer
111 }; // namespace android
112