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 #include <ui/ColorSpace.h>
20 #include <utils/Log.h>
21
22 #ifdef __ANDROID__ // Layoutlib does not support hardware buffers or native windows
23 #include <android/hardware_buffer.h>
24 #include <android/native_window.h>
25 #endif
26
27 #include <algorithm>
28 #include <cmath>
29 #include <Properties.h>
30
31 namespace android {
32 namespace uirenderer {
33
34 #ifdef __ANDROID__ // Layoutlib does not support hardware buffers or native windows
createImageInfo(int32_t width,int32_t height,int32_t format,sk_sp<SkColorSpace> colorSpace)35 static inline SkImageInfo createImageInfo(int32_t width, int32_t height, int32_t format,
36 sk_sp<SkColorSpace> colorSpace) {
37 SkColorType colorType = kUnknown_SkColorType;
38 SkAlphaType alphaType = kOpaque_SkAlphaType;
39 switch (format) {
40 case AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM:
41 colorType = kN32_SkColorType;
42 alphaType = kPremul_SkAlphaType;
43 break;
44 case AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM:
45 colorType = kN32_SkColorType;
46 alphaType = kOpaque_SkAlphaType;
47 break;
48 case AHARDWAREBUFFER_FORMAT_R5G6B5_UNORM:
49 colorType = kRGB_565_SkColorType;
50 alphaType = kOpaque_SkAlphaType;
51 break;
52 case AHARDWAREBUFFER_FORMAT_R10G10B10A2_UNORM:
53 colorType = kRGBA_1010102_SkColorType;
54 alphaType = kPremul_SkAlphaType;
55 break;
56 case AHARDWAREBUFFER_FORMAT_R16G16B16A16_FLOAT:
57 colorType = kRGBA_F16_SkColorType;
58 alphaType = kPremul_SkAlphaType;
59 break;
60 default:
61 ALOGV("Unsupported format: %d, return unknown by default", format);
62 break;
63 }
64 return SkImageInfo::Make(width, height, colorType, alphaType, colorSpace);
65 }
66
ANativeWindowToImageInfo(const ANativeWindow_Buffer & buffer,sk_sp<SkColorSpace> colorSpace)67 SkImageInfo ANativeWindowToImageInfo(const ANativeWindow_Buffer& buffer,
68 sk_sp<SkColorSpace> colorSpace) {
69 return createImageInfo(buffer.width, buffer.height, buffer.format, colorSpace);
70 }
71
BufferDescriptionToImageInfo(const AHardwareBuffer_Desc & bufferDesc,sk_sp<SkColorSpace> colorSpace)72 SkImageInfo BufferDescriptionToImageInfo(const AHardwareBuffer_Desc& bufferDesc,
73 sk_sp<SkColorSpace> colorSpace) {
74 return createImageInfo(bufferDesc.width, bufferDesc.height, bufferDesc.format, colorSpace);
75 }
76
ColorTypeToBufferFormat(SkColorType colorType)77 uint32_t ColorTypeToBufferFormat(SkColorType colorType) {
78 switch (colorType) {
79 case kRGBA_8888_SkColorType:
80 return AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM;
81 case kRGBA_F16_SkColorType:
82 return AHARDWAREBUFFER_FORMAT_R16G16B16A16_FLOAT;
83 case kRGB_565_SkColorType:
84 return AHARDWAREBUFFER_FORMAT_R5G6B5_UNORM;
85 case kRGB_888x_SkColorType:
86 return AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM;
87 case kRGBA_1010102_SkColorType:
88 return AHARDWAREBUFFER_FORMAT_R10G10B10A2_UNORM;
89 case kARGB_4444_SkColorType:
90 // Hardcoding the value from android::PixelFormat
91 static constexpr uint64_t kRGBA4444 = 7;
92 return kRGBA4444;
93 default:
94 ALOGV("Unsupported colorType: %d, return RGBA_8888 by default", (int)colorType);
95 return AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM;
96 }
97 }
98 #endif
99
100 namespace {
101 static constexpr skcms_TransferFunction k2Dot6 = {2.6f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f};
102
103 // Skia's SkNamedGamut::kDisplayP3 is based on a white point of D65. This gamut
104 // matches the white point used by ColorSpace.Named.DCIP3.
105 static constexpr skcms_Matrix3x3 kDCIP3 = {{
106 {0.486143, 0.323835, 0.154234},
107 {0.226676, 0.710327, 0.0629966},
108 {0.000800549, 0.0432385, 0.78275},
109 }};
110
nearlyEqual(float a,float b)111 static bool nearlyEqual(float a, float b) {
112 // By trial and error, this is close enough to match for the ADataSpaces we
113 // compare for.
114 return ::fabs(a - b) < .002f;
115 }
116
nearlyEqual(const skcms_TransferFunction & x,const skcms_TransferFunction & y)117 static bool nearlyEqual(const skcms_TransferFunction& x, const skcms_TransferFunction& y) {
118 return nearlyEqual(x.g, y.g)
119 && nearlyEqual(x.a, y.a)
120 && nearlyEqual(x.b, y.b)
121 && nearlyEqual(x.c, y.c)
122 && nearlyEqual(x.d, y.d)
123 && nearlyEqual(x.e, y.e)
124 && nearlyEqual(x.f, y.f);
125 }
126
nearlyEqual(const skcms_Matrix3x3 & x,const skcms_Matrix3x3 & y)127 static bool nearlyEqual(const skcms_Matrix3x3& x, const skcms_Matrix3x3& y) {
128 for (int i = 0; i < 3; i++) {
129 for (int j = 0; j < 3; j++) {
130 if (!nearlyEqual(x.vals[i][j], y.vals[i][j])) return false;
131 }
132 }
133 return true;
134 }
135
136 } // anonymous namespace
137
ColorSpaceToADataSpace(SkColorSpace * colorSpace,SkColorType colorType)138 android_dataspace ColorSpaceToADataSpace(SkColorSpace* colorSpace, SkColorType colorType) {
139 if (!colorSpace) {
140 return HAL_DATASPACE_UNKNOWN;
141 }
142
143 if (colorSpace->isSRGB()) {
144 if (colorType == kRGBA_F16_SkColorType) {
145 return HAL_DATASPACE_V0_SCRGB;
146 }
147 return HAL_DATASPACE_V0_SRGB;
148 }
149
150 skcms_TransferFunction fn;
151 if (!colorSpace->isNumericalTransferFn(&fn)) {
152 // pq with the default white point
153 auto rec2020PQ = SkColorSpace::MakeRGB(GetPQSkTransferFunction(), SkNamedGamut::kRec2020);
154 if (SkColorSpace::Equals(colorSpace, rec2020PQ.get())) {
155 return HAL_DATASPACE_BT2020_PQ;
156 }
157 // standard PQ
158 rec2020PQ = SkColorSpace::MakeRGB(SkNamedTransferFn::kPQ, SkNamedGamut::kRec2020);
159 if (SkColorSpace::Equals(colorSpace, rec2020PQ.get())) {
160 return HAL_DATASPACE_BT2020_PQ;
161 }
162 LOG_ALWAYS_FATAL("Only select non-numerical transfer functions are supported");
163 }
164
165 skcms_Matrix3x3 gamut;
166 LOG_ALWAYS_FATAL_IF(!colorSpace->toXYZD50(&gamut));
167
168 if (nearlyEqual(gamut, SkNamedGamut::kSRGB)) {
169 if (nearlyEqual(fn, SkNamedTransferFn::kLinear)) {
170 // Skia doesn't differentiate amongst the RANGES. In Java, we associate
171 // LINEAR_EXTENDED_SRGB with F16, and LINEAR_SRGB with other Configs.
172 // Make the same association here.
173 if (colorType == kRGBA_F16_SkColorType) {
174 return HAL_DATASPACE_V0_SCRGB_LINEAR;
175 }
176 return HAL_DATASPACE_V0_SRGB_LINEAR;
177 }
178
179 if (nearlyEqual(fn, SkNamedTransferFn::kRec2020)) {
180 return HAL_DATASPACE_V0_BT709;
181 }
182 }
183
184 if (nearlyEqual(fn, SkNamedTransferFn::kSRGB) && nearlyEqual(gamut, SkNamedGamut::kDisplayP3)) {
185 return HAL_DATASPACE_DISPLAY_P3;
186 }
187
188 if (nearlyEqual(fn, SkNamedTransferFn::k2Dot2) && nearlyEqual(gamut, SkNamedGamut::kAdobeRGB)) {
189 return HAL_DATASPACE_ADOBE_RGB;
190 }
191
192 if (nearlyEqual(fn, SkNamedTransferFn::kRec2020) &&
193 nearlyEqual(gamut, SkNamedGamut::kRec2020)) {
194 return HAL_DATASPACE_BT2020;
195 }
196
197 if (nearlyEqual(fn, k2Dot6) && nearlyEqual(gamut, kDCIP3)) {
198 return HAL_DATASPACE_DCI_P3;
199 }
200
201 return HAL_DATASPACE_UNKNOWN;
202 }
203
DataSpaceToColorSpace(android_dataspace dataspace)204 sk_sp<SkColorSpace> DataSpaceToColorSpace(android_dataspace dataspace) {
205 if (dataspace == HAL_DATASPACE_UNKNOWN) {
206 return SkColorSpace::MakeSRGB();
207 }
208 if (dataspace == HAL_DATASPACE_DCI_P3) {
209 // This cannot be handled by the switch statements below because it
210 // needs to use the locally-defined kDCIP3 gamut, rather than the one in
211 // Skia (SkNamedGamut), which is used for other data spaces with
212 // HAL_DATASPACE_STANDARD_DCI_P3 (e.g. HAL_DATASPACE_DISPLAY_P3).
213 return SkColorSpace::MakeRGB(k2Dot6, kDCIP3);
214 }
215
216 skcms_Matrix3x3 gamut;
217 switch (dataspace & HAL_DATASPACE_STANDARD_MASK) {
218 case HAL_DATASPACE_STANDARD_BT709:
219 gamut = SkNamedGamut::kSRGB;
220 break;
221 case HAL_DATASPACE_STANDARD_BT2020:
222 gamut = SkNamedGamut::kRec2020;
223 break;
224 case HAL_DATASPACE_STANDARD_DCI_P3:
225 gamut = SkNamedGamut::kDisplayP3;
226 break;
227 case HAL_DATASPACE_STANDARD_ADOBE_RGB:
228 gamut = SkNamedGamut::kAdobeRGB;
229 break;
230 case HAL_DATASPACE_STANDARD_UNSPECIFIED:
231 return nullptr;
232 case HAL_DATASPACE_STANDARD_BT601_625:
233 case HAL_DATASPACE_STANDARD_BT601_625_UNADJUSTED:
234 case HAL_DATASPACE_STANDARD_BT601_525:
235 case HAL_DATASPACE_STANDARD_BT601_525_UNADJUSTED:
236 case HAL_DATASPACE_STANDARD_BT2020_CONSTANT_LUMINANCE:
237 case HAL_DATASPACE_STANDARD_BT470M:
238 case HAL_DATASPACE_STANDARD_FILM:
239 default:
240 ALOGV("Unsupported Gamut: %d", dataspace);
241 return nullptr;
242 }
243
244 switch (dataspace & HAL_DATASPACE_TRANSFER_MASK) {
245 case HAL_DATASPACE_TRANSFER_LINEAR:
246 return SkColorSpace::MakeRGB(SkNamedTransferFn::kLinear, gamut);
247 case HAL_DATASPACE_TRANSFER_SRGB:
248 return SkColorSpace::MakeRGB(SkNamedTransferFn::kSRGB, gamut);
249 case HAL_DATASPACE_TRANSFER_GAMMA2_2:
250 return SkColorSpace::MakeRGB({2.2f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f}, gamut);
251 case HAL_DATASPACE_TRANSFER_GAMMA2_6:
252 return SkColorSpace::MakeRGB(k2Dot6, gamut);
253 case HAL_DATASPACE_TRANSFER_GAMMA2_8:
254 return SkColorSpace::MakeRGB({2.8f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f}, gamut);
255 case HAL_DATASPACE_TRANSFER_ST2084:
256 return SkColorSpace::MakeRGB(SkNamedTransferFn::kPQ, gamut);
257 case HAL_DATASPACE_TRANSFER_SMPTE_170M:
258 return SkColorSpace::MakeRGB(SkNamedTransferFn::kRec2020, gamut);
259 case HAL_DATASPACE_TRANSFER_UNSPECIFIED:
260 return nullptr;
261 case HAL_DATASPACE_TRANSFER_HLG:
262 default:
263 ALOGV("Unsupported Gamma: %d", dataspace);
264 return nullptr;
265 }
266 }
267
268 template<typename T>
clamp(T x,T min,T max)269 static constexpr T clamp(T x, T min, T max) {
270 return x < min ? min : x > max ? max : x;
271 }
272
273 //static const float2 ILLUMINANT_D50_XY = {0.34567f, 0.35850f};
274 static const float3 ILLUMINANT_D50_XYZ = {0.964212f, 1.0f, 0.825188f};
275 static const mat3 BRADFORD = mat3{
276 float3{ 0.8951f, -0.7502f, 0.0389f},
277 float3{ 0.2664f, 1.7135f, -0.0685f},
278 float3{-0.1614f, 0.0367f, 1.0296f}
279 };
280
adaptation(const mat3 & matrix,const float3 & srcWhitePoint,const float3 & dstWhitePoint)281 static mat3 adaptation(const mat3& matrix, const float3& srcWhitePoint, const float3& dstWhitePoint) {
282 float3 srcLMS = matrix * srcWhitePoint;
283 float3 dstLMS = matrix * dstWhitePoint;
284 return inverse(matrix) * mat3{dstLMS / srcLMS} * matrix;
285 }
286
287 namespace LabColorSpace {
288
289 static constexpr float A = 216.0f / 24389.0f;
290 static constexpr float B = 841.0f / 108.0f;
291 static constexpr float C = 4.0f / 29.0f;
292 static constexpr float D = 6.0f / 29.0f;
293
toXyz(const Lab & lab)294 float3 toXyz(const Lab& lab) {
295 float3 v { lab.L, lab.a, lab.b };
296 v[0] = clamp(v[0], 0.0f, 100.0f);
297 v[1] = clamp(v[1], -128.0f, 128.0f);
298 v[2] = clamp(v[2], -128.0f, 128.0f);
299
300 float fy = (v[0] + 16.0f) / 116.0f;
301 float fx = fy + (v[1] * 0.002f);
302 float fz = fy - (v[2] * 0.005f);
303 float X = fx > D ? fx * fx * fx : (1.0f / B) * (fx - C);
304 float Y = fy > D ? fy * fy * fy : (1.0f / B) * (fy - C);
305 float Z = fz > D ? fz * fz * fz : (1.0f / B) * (fz - C);
306
307 v[0] = X * ILLUMINANT_D50_XYZ[0];
308 v[1] = Y * ILLUMINANT_D50_XYZ[1];
309 v[2] = Z * ILLUMINANT_D50_XYZ[2];
310
311 return v;
312 }
313
fromXyz(const float3 & v)314 Lab fromXyz(const float3& v) {
315 float X = v[0] / ILLUMINANT_D50_XYZ[0];
316 float Y = v[1] / ILLUMINANT_D50_XYZ[1];
317 float Z = v[2] / ILLUMINANT_D50_XYZ[2];
318
319 float fx = X > A ? pow(X, 1.0f / 3.0f) : B * X + C;
320 float fy = Y > A ? pow(Y, 1.0f / 3.0f) : B * Y + C;
321 float fz = Z > A ? pow(Z, 1.0f / 3.0f) : B * Z + C;
322
323 float L = 116.0f * fy - 16.0f;
324 float a = 500.0f * (fx - fy);
325 float b = 200.0f * (fy - fz);
326
327 return Lab {
328 clamp(L, 0.0f, 100.0f),
329 clamp(a, -128.0f, 128.0f),
330 clamp(b, -128.0f, 128.0f)
331 };
332 }
333
334 };
335
sRGBToLab(SkColor color)336 Lab sRGBToLab(SkColor color) {
337 auto colorSpace = ColorSpace::sRGB();
338 float3 rgb;
339 rgb.r = SkColorGetR(color) / 255.0f;
340 rgb.g = SkColorGetG(color) / 255.0f;
341 rgb.b = SkColorGetB(color) / 255.0f;
342 float3 xyz = colorSpace.rgbToXYZ(rgb);
343 float3 srcXYZ = ColorSpace::XYZ(float3{colorSpace.getWhitePoint(), 1});
344 xyz = adaptation(BRADFORD, srcXYZ, ILLUMINANT_D50_XYZ) * xyz;
345 return LabColorSpace::fromXyz(xyz);
346 }
347
LabToSRGB(const Lab & lab,SkAlpha alpha)348 SkColor LabToSRGB(const Lab& lab, SkAlpha alpha) {
349 auto colorSpace = ColorSpace::sRGB();
350 float3 xyz = LabColorSpace::toXyz(lab);
351 float3 dstXYZ = ColorSpace::XYZ(float3{colorSpace.getWhitePoint(), 1});
352 xyz = adaptation(BRADFORD, ILLUMINANT_D50_XYZ, dstXYZ) * xyz;
353 float3 rgb = colorSpace.xyzToRGB(xyz);
354 return SkColorSetARGB(alpha,
355 static_cast<uint8_t>(rgb.r * 255),
356 static_cast<uint8_t>(rgb.g * 255),
357 static_cast<uint8_t>(rgb.b * 255));
358 }
359
GetPQSkTransferFunction(float sdr_white_level)360 skcms_TransferFunction GetPQSkTransferFunction(float sdr_white_level) {
361 if (sdr_white_level <= 0.f) {
362 sdr_white_level = Properties::defaultSdrWhitePoint;
363 }
364 // The generic PQ transfer function produces normalized luminance values i.e.
365 // the range 0-1 represents 0-10000 nits for the reference display, but we
366 // want to map 1.0 to |sdr_white_level| nits so we need to scale accordingly.
367 const double w = 10000. / sdr_white_level;
368 // Distribute scaling factor W by scaling A and B with X ^ (1/F):
369 // ((A + Bx^C) / (D + Ex^C))^F * W = ((A + Bx^C) / (D + Ex^C) * W^(1/F))^F
370 // See https://crbug.com/1058580#c32 for discussion.
371 skcms_TransferFunction fn = SkNamedTransferFn::kPQ;
372 const double ws = pow(w, 1. / fn.f);
373 fn.a = ws * fn.a;
374 fn.b = ws * fn.b;
375 return fn;
376 }
377
378 } // namespace uirenderer
379 } // namespace android
380