1 /*
2 * Copyright (C) 2010 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 "Debug.h"
18 #include "GammaFontRenderer.h"
19 #include "Properties.h"
20
21 namespace android {
22 namespace uirenderer {
23
24 ///////////////////////////////////////////////////////////////////////////////
25 // Utils
26 ///////////////////////////////////////////////////////////////////////////////
27
luminance(const SkPaint * paint)28 static int luminance(const SkPaint* paint) {
29 uint32_t c = paint->getColor();
30 const int r = (c >> 16) & 0xFF;
31 const int g = (c >> 8) & 0xFF;
32 const int b = (c ) & 0xFF;
33 return (r * 2 + g * 5 + b) >> 3;
34 }
35
36 ///////////////////////////////////////////////////////////////////////////////
37 // Base class GammaFontRenderer
38 ///////////////////////////////////////////////////////////////////////////////
39
createRenderer()40 GammaFontRenderer* GammaFontRenderer::createRenderer() {
41 // Choose the best renderer
42 char property[PROPERTY_VALUE_MAX];
43 if (property_get(PROPERTY_TEXT_GAMMA_METHOD, property, DEFAULT_TEXT_GAMMA_METHOD) > 0) {
44 if (!strcasecmp(property, "lookup")) {
45 return new LookupGammaFontRenderer();
46 } else if (!strcasecmp(property, "shader")) {
47 return new ShaderGammaFontRenderer(false);
48 } else if (!strcasecmp(property, "shader3")) {
49 return new ShaderGammaFontRenderer(true);
50 }
51 }
52
53 return new Lookup3GammaFontRenderer();
54 }
55
GammaFontRenderer()56 GammaFontRenderer::GammaFontRenderer() {
57 // Get the renderer properties
58 char property[PROPERTY_VALUE_MAX];
59
60 // Get the gamma
61 mGamma = DEFAULT_TEXT_GAMMA;
62 if (property_get(PROPERTY_TEXT_GAMMA, property, nullptr) > 0) {
63 INIT_LOGD(" Setting text gamma to %s", property);
64 mGamma = atof(property);
65 } else {
66 INIT_LOGD(" Using default text gamma of %.2f", DEFAULT_TEXT_GAMMA);
67 }
68
69 // Get the black gamma threshold
70 mBlackThreshold = DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD;
71 if (property_get(PROPERTY_TEXT_BLACK_GAMMA_THRESHOLD, property, nullptr) > 0) {
72 INIT_LOGD(" Setting text black gamma threshold to %s", property);
73 mBlackThreshold = atoi(property);
74 } else {
75 INIT_LOGD(" Using default text black gamma threshold of %d",
76 DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD);
77 }
78
79 // Get the white gamma threshold
80 mWhiteThreshold = DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD;
81 if (property_get(PROPERTY_TEXT_WHITE_GAMMA_THRESHOLD, property, nullptr) > 0) {
82 INIT_LOGD(" Setting text white gamma threshold to %s", property);
83 mWhiteThreshold = atoi(property);
84 } else {
85 INIT_LOGD(" Using default white black gamma threshold of %d",
86 DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD);
87 }
88 }
89
~GammaFontRenderer()90 GammaFontRenderer::~GammaFontRenderer() {
91 }
92
93 ///////////////////////////////////////////////////////////////////////////////
94 // Shader-based renderer
95 ///////////////////////////////////////////////////////////////////////////////
96
ShaderGammaFontRenderer(bool multiGamma)97 ShaderGammaFontRenderer::ShaderGammaFontRenderer(bool multiGamma)
98 : GammaFontRenderer() {
99 INIT_LOGD("Creating shader gamma font renderer");
100 mRenderer = nullptr;
101 mMultiGamma = multiGamma;
102 }
103
describe(ProgramDescription & description,const SkPaint * paint) const104 void ShaderGammaFontRenderer::describe(ProgramDescription& description,
105 const SkPaint* paint) const {
106 if (paint->getShader() == nullptr) {
107 if (mMultiGamma) {
108 const int l = luminance(paint);
109
110 if (l <= mBlackThreshold) {
111 description.hasGammaCorrection = true;
112 description.gamma = mGamma;
113 } else if (l >= mWhiteThreshold) {
114 description.hasGammaCorrection = true;
115 description.gamma = 1.0f / mGamma;
116 }
117 } else {
118 description.hasGammaCorrection = true;
119 description.gamma = 1.0f / mGamma;
120 }
121 }
122 }
123
setupProgram(ProgramDescription & description,Program & program) const124 void ShaderGammaFontRenderer::setupProgram(ProgramDescription& description,
125 Program& program) const {
126 if (description.hasGammaCorrection) {
127 glUniform1f(program.getUniform("gamma"), description.gamma);
128 }
129 }
130
endPrecaching()131 void ShaderGammaFontRenderer::endPrecaching() {
132 if (mRenderer) {
133 mRenderer->endPrecaching();
134 }
135 }
136
137 ///////////////////////////////////////////////////////////////////////////////
138 // Lookup-based renderer
139 ///////////////////////////////////////////////////////////////////////////////
140
LookupGammaFontRenderer()141 LookupGammaFontRenderer::LookupGammaFontRenderer()
142 : GammaFontRenderer() {
143 INIT_LOGD("Creating lookup gamma font renderer");
144
145 // Compute the gamma tables
146 const float gamma = 1.0f / mGamma;
147
148 for (uint32_t i = 0; i <= 255; i++) {
149 mGammaTable[i] = uint8_t((float)::floor(pow(i / 255.0f, gamma) * 255.0f + 0.5f));
150 }
151
152 mRenderer = nullptr;
153 }
154
endPrecaching()155 void LookupGammaFontRenderer::endPrecaching() {
156 if (mRenderer) {
157 mRenderer->endPrecaching();
158 }
159 }
160
161 ///////////////////////////////////////////////////////////////////////////////
162 // Lookup-based renderer, using 3 different correction tables
163 ///////////////////////////////////////////////////////////////////////////////
164
Lookup3GammaFontRenderer()165 Lookup3GammaFontRenderer::Lookup3GammaFontRenderer()
166 : GammaFontRenderer() {
167 INIT_LOGD("Creating lookup3 gamma font renderer");
168
169 // Compute the gamma tables
170 const float blackGamma = mGamma;
171 const float whiteGamma = 1.0f / mGamma;
172
173 for (uint32_t i = 0; i <= 255; i++) {
174 const float v = i / 255.0f;
175 const float black = pow(v, blackGamma);
176 const float white = pow(v, whiteGamma);
177
178 mGammaTable[i] = i;
179 mGammaTable[256 + i] = uint8_t((float)::floor(black * 255.0f + 0.5f));
180 mGammaTable[512 + i] = uint8_t((float)::floor(white * 255.0f + 0.5f));
181 }
182
183 memset(mRenderers, 0, sizeof(FontRenderer*) * kGammaCount);
184 memset(mRenderersUsageCount, 0, sizeof(uint32_t) * kGammaCount);
185 }
186
endPrecaching()187 void Lookup3GammaFontRenderer::endPrecaching() {
188 for (int i = 0; i < kGammaCount; i++) {
189 if (mRenderers[i]) {
190 mRenderers[i]->endPrecaching();
191 }
192 }
193 }
194
clear()195 void Lookup3GammaFontRenderer::clear() {
196 for (int i = 0; i < kGammaCount; i++) {
197 mRenderers[i].release();
198 }
199 }
200
flush()201 void Lookup3GammaFontRenderer::flush() {
202 int count = 0;
203 int min = -1;
204 uint32_t minCount = UINT_MAX;
205
206 for (int i = 0; i < kGammaCount; i++) {
207 if (mRenderers[i]) {
208 count++;
209 if (mRenderersUsageCount[i] < minCount) {
210 minCount = mRenderersUsageCount[i];
211 min = i;
212 }
213 }
214 }
215
216 if (count <= 1 || min < 0) return;
217
218 mRenderers[min].release();
219
220 // Also eliminate the caches for large glyphs, as they consume significant memory
221 for (int i = 0; i < kGammaCount; ++i) {
222 if (mRenderers[i]) {
223 mRenderers[i]->flushLargeCaches();
224 }
225 }
226 }
227
getRenderer(Gamma gamma)228 FontRenderer* Lookup3GammaFontRenderer::getRenderer(Gamma gamma) {
229 if (!mRenderers[gamma]) {
230 mRenderers[gamma].reset(new FontRenderer());
231 mRenderers[gamma]->setGammaTable(&mGammaTable[gamma * 256]);
232 }
233 mRenderersUsageCount[gamma]++;
234 return mRenderers[gamma].get();
235 }
236
getFontRenderer(const SkPaint * paint)237 FontRenderer& Lookup3GammaFontRenderer::getFontRenderer(const SkPaint* paint) {
238 if (paint->getShader() == nullptr) {
239 const int l = luminance(paint);
240
241 if (l <= mBlackThreshold) {
242 return *getRenderer(kGammaBlack);
243 } else if (l >= mWhiteThreshold) {
244 return *getRenderer(kGammaWhite);
245 }
246 }
247 return *getRenderer(kGammaDefault);
248 }
249
250 }; // namespace uirenderer
251 }; // namespace android
252