1 /*
2  * Copyright (C) 2015 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 #ifndef COLOR_H
17 #define COLOR_H
18 
19 #include <math.h>
20 #include <system/graphics.h>
21 
22 #include <SkColor.h>
23 #include <SkColorSpace.h>
24 
25 namespace android {
26 namespace uirenderer {
27 namespace Color {
28 enum Color {
29     Red_500 = 0xFFF44336,
30     Pink_500 = 0xFFE91E63,
31     Purple_500 = 0xFF9C27B0,
32     DeepPurple_500 = 0xFF673AB7,
33     Indigo_500 = 0xFF3F51B5,
34     Blue_500 = 0xFF2196F3,
35     LightBlue_300 = 0xFF4FC3F7,
36     LightBlue_500 = 0xFF03A9F4,
37     Cyan_500 = 0xFF00BCD4,
38     Teal_500 = 0xFF008577,
39     Teal_700 = 0xFF00796B,
40     Green_500 = 0xFF4CAF50,
41     Green_700 = 0xFF388E3C,
42     LightGreen_500 = 0xFF8BC34A,
43     LightGreen_700 = 0xFF689F38,
44     Lime_500 = 0xFFCDDC39,
45     Yellow_500 = 0xFFFFEB3B,
46     Amber_500 = 0xFFFFC107,
47     Orange_500 = 0xFFFF9800,
48     DeepOrange_500 = 0xFFFF5722,
49     Brown_500 = 0xFF795548,
50     Grey_200 = 0xFFEEEEEE,
51     Grey_500 = 0xFF9E9E9E,
52     Grey_700 = 0xFF616161,
53     BlueGrey_500 = 0xFF607D8B,
54     Transparent = 0x00000000,
55     Black = 0xFF000000,
56     White = 0xFFFFFFFF,
57 };
58 }
59 
60 static_assert(Color::White == SK_ColorWHITE, "color format has changed");
61 static_assert(Color::Black == SK_ColorBLACK, "color format has changed");
62 
63 // Array of bright (500 intensity) colors for synthetic content
64 static const Color::Color BrightColors[] = {
65         Color::Red_500,    Color::Pink_500,  Color::Purple_500,     Color::DeepPurple_500,
66         Color::Indigo_500, Color::Blue_500,  Color::LightBlue_500,  Color::Cyan_500,
67         Color::Teal_500,   Color::Green_500, Color::LightGreen_500, Color::Lime_500,
68         Color::Yellow_500, Color::Amber_500, Color::Orange_500,     Color::DeepOrange_500,
69         Color::Brown_500,  Color::Grey_500,  Color::BlueGrey_500,
70 };
71 static constexpr int BrightColorsCount = sizeof(BrightColors) / sizeof(Color::Color);
72 
73 enum class TransferFunctionType : int8_t { None = 0, Full, Limited, Gamma };
74 
75 // Opto-electronic conversion function for the sRGB color space
76 // Takes a linear sRGB value and converts it to a gamma-encoded sRGB value
OECF_sRGB(float linear)77 static constexpr float OECF_sRGB(float linear) {
78     // IEC 61966-2-1:1999
79     return linear <= 0.0031308f ? linear * 12.92f : (powf(linear, 1.0f / 2.4f) * 1.055f) - 0.055f;
80 }
81 
82 // Opto-electronic conversion function for the sRGB color space
83 // Takes a linear sRGB value and converts it to a gamma-encoded sRGB value
84 // This function returns the input unmodified if linear blending is not enabled
OECF(float linear)85 static constexpr float OECF(float linear) {
86 #ifdef ANDROID_ENABLE_LINEAR_BLENDING
87     return OECF_sRGB(linear);
88 #else
89     return linear;
90 #endif
91 }
92 
93 // Electro-optical conversion function for the sRGB color space
94 // Takes a gamma-encoded sRGB value and converts it to a linear sRGB value
EOCF_sRGB(float srgb)95 static constexpr float EOCF_sRGB(float srgb) {
96     // IEC 61966-2-1:1999
97     return srgb <= 0.04045f ? srgb / 12.92f : powf((srgb + 0.055f) / 1.055f, 2.4f);
98 }
99 
100 // Electro-optical conversion function for the sRGB color space
101 // Takes a gamma-encoded sRGB value and converts it to a linear sRGB value
102 // This function returns the input unmodified if linear blending is not enabled
EOCF(float srgb)103 static constexpr float EOCF(float srgb) {
104 #ifdef ANDROID_ENABLE_LINEAR_BLENDING
105     return EOCF_sRGB(srgb);
106 #else
107     return srgb;
108 #endif
109 }
110 
111 // Returns whether the specified color space's transfer function can be
112 // approximated with the native sRGB transfer function. This method
113 // returns true for sRGB, gamma 2.2 and Display P3 for instance
114 bool transferFunctionCloseToSRGB(const SkColorSpace* colorSpace);
115 
116 sk_sp<SkColorSpace> DataSpaceToColorSpace(android_dataspace dataspace);
117 } /* namespace uirenderer */
118 } /* namespace android */
119 
120 #endif /* COLOR_H */
121