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      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 #define LOG_TAG "OpenGLRenderer"
     18 
     19 #include "Debug.h"
     20 #include "GammaFontRenderer.h"
     21 #include "Properties.h"
     22 
     23 namespace android {
     24 namespace uirenderer {
     25 
     26 ///////////////////////////////////////////////////////////////////////////////
     27 // Utils
     28 ///////////////////////////////////////////////////////////////////////////////
     29 
     30 static int luminance(const SkPaint* paint) {
     31     uint32_t c = paint->getColor();
     32     const int r = (c >> 16) & 0xFF;
     33     const int g = (c >>  8) & 0xFF;
     34     const int b = (c      ) & 0xFF;
     35     return (r * 2 + g * 5 + b) >> 3;
     36 }
     37 
     38 ///////////////////////////////////////////////////////////////////////////////
     39 // Base class GammaFontRenderer
     40 ///////////////////////////////////////////////////////////////////////////////
     41 
     42 GammaFontRenderer* GammaFontRenderer::createRenderer() {
     43     // Choose the best renderer
     44     char property[PROPERTY_VALUE_MAX];
     45     if (property_get(PROPERTY_TEXT_GAMMA_METHOD, property, DEFAULT_TEXT_GAMMA_METHOD) > 0) {
     46         if (!strcasecmp(property, "lookup")) {
     47             return new LookupGammaFontRenderer();
     48         } else if (!strcasecmp(property, "shader")) {
     49             return new ShaderGammaFontRenderer(false);
     50         } else if (!strcasecmp(property, "shader3")) {
     51             return new ShaderGammaFontRenderer(true);
     52         }
     53     }
     54 
     55     return new Lookup3GammaFontRenderer();
     56 }
     57 
     58 GammaFontRenderer::GammaFontRenderer() {
     59     // Get the renderer properties
     60     char property[PROPERTY_VALUE_MAX];
     61 
     62     // Get the gamma
     63     mGamma = DEFAULT_TEXT_GAMMA;
     64     if (property_get(PROPERTY_TEXT_GAMMA, property, NULL) > 0) {
     65         INIT_LOGD("  Setting text gamma to %s", property);
     66         mGamma = atof(property);
     67     } else {
     68         INIT_LOGD("  Using default text gamma of %.2f", DEFAULT_TEXT_GAMMA);
     69     }
     70 
     71     // Get the black gamma threshold
     72     mBlackThreshold = DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD;
     73     if (property_get(PROPERTY_TEXT_BLACK_GAMMA_THRESHOLD, property, NULL) > 0) {
     74         INIT_LOGD("  Setting text black gamma threshold to %s", property);
     75         mBlackThreshold = atoi(property);
     76     } else {
     77         INIT_LOGD("  Using default text black gamma threshold of %d",
     78                 DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD);
     79     }
     80 
     81     // Get the white gamma threshold
     82     mWhiteThreshold = DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD;
     83     if (property_get(PROPERTY_TEXT_WHITE_GAMMA_THRESHOLD, property, NULL) > 0) {
     84         INIT_LOGD("  Setting text white gamma threshold to %s", property);
     85         mWhiteThreshold = atoi(property);
     86     } else {
     87         INIT_LOGD("  Using default white black gamma threshold of %d",
     88                 DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD);
     89     }
     90 }
     91 
     92 GammaFontRenderer::~GammaFontRenderer() {
     93 }
     94 
     95 ///////////////////////////////////////////////////////////////////////////////
     96 // Shader-based renderer
     97 ///////////////////////////////////////////////////////////////////////////////
     98 
     99 ShaderGammaFontRenderer::ShaderGammaFontRenderer(bool multiGamma): GammaFontRenderer() {
    100     INIT_LOGD("Creating shader gamma font renderer");
    101     mRenderer = NULL;
    102     mMultiGamma = multiGamma;
    103 }
    104 
    105 void ShaderGammaFontRenderer::describe(ProgramDescription& description,
    106         const SkPaint* paint) const {
    107     if (paint->getShader() == NULL) {
    108         if (mMultiGamma) {
    109             const int l = luminance(paint);
    110 
    111             if (l <= mBlackThreshold) {
    112                 description.hasGammaCorrection = true;
    113                 description.gamma = mGamma;
    114             } else if (l >= mWhiteThreshold) {
    115                 description.hasGammaCorrection = true;
    116                 description.gamma = 1.0f / mGamma;
    117             }
    118         } else {
    119             description.hasGammaCorrection = true;
    120             description.gamma = 1.0f / mGamma;
    121         }
    122     }
    123 }
    124 
    125 void ShaderGammaFontRenderer::setupProgram(ProgramDescription& description,
    126         Program* program) const {
    127     if (description.hasGammaCorrection) {
    128         glUniform1f(program->getUniform("gamma"), description.gamma);
    129     }
    130 }
    131 
    132 void ShaderGammaFontRenderer::endPrecaching() {
    133     if (mRenderer) {
    134         mRenderer->endPrecaching();
    135     }
    136 }
    137 
    138 ///////////////////////////////////////////////////////////////////////////////
    139 // Lookup-based renderer
    140 ///////////////////////////////////////////////////////////////////////////////
    141 
    142 LookupGammaFontRenderer::LookupGammaFontRenderer(): 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 = NULL;
    153 }
    154 
    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 
    165 Lookup3GammaFontRenderer::Lookup3GammaFontRenderer(): GammaFontRenderer() {
    166     INIT_LOGD("Creating lookup3 gamma font renderer");
    167 
    168     // Compute the gamma tables
    169     const float blackGamma = mGamma;
    170     const float whiteGamma = 1.0f / mGamma;
    171 
    172     for (uint32_t i = 0; i <= 255; i++) {
    173         const float v = i / 255.0f;
    174         const float black = pow(v, blackGamma);
    175         const float white = pow(v, whiteGamma);
    176 
    177         mGammaTable[i] = i;
    178         mGammaTable[256 + i] = uint8_t((float)::floor(black * 255.0f + 0.5f));
    179         mGammaTable[512 + i] = uint8_t((float)::floor(white * 255.0f + 0.5f));
    180     }
    181 
    182     memset(mRenderers, 0, sizeof(FontRenderer*) * kGammaCount);
    183     memset(mRenderersUsageCount, 0, sizeof(uint32_t) * kGammaCount);
    184 }
    185 
    186 Lookup3GammaFontRenderer::~Lookup3GammaFontRenderer() {
    187     for (int i = 0; i < kGammaCount; i++) {
    188         delete mRenderers[i];
    189     }
    190 }
    191 
    192 void Lookup3GammaFontRenderer::endPrecaching() {
    193     for (int i = 0; i < kGammaCount; i++) {
    194         if (mRenderers[i]) {
    195             mRenderers[i]->endPrecaching();
    196         }
    197     }
    198 }
    199 
    200 void Lookup3GammaFontRenderer::clear() {
    201     for (int i = 0; i < kGammaCount; i++) {
    202         delete mRenderers[i];
    203         mRenderers[i] = NULL;
    204     }
    205 }
    206 
    207 void Lookup3GammaFontRenderer::flush() {
    208     int count = 0;
    209     int min = -1;
    210     uint32_t minCount = UINT_MAX;
    211 
    212     for (int i = 0; i < kGammaCount; i++) {
    213         if (mRenderers[i]) {
    214             count++;
    215             if (mRenderersUsageCount[i] < minCount) {
    216                 minCount = mRenderersUsageCount[i];
    217                 min = i;
    218             }
    219         }
    220     }
    221 
    222     if (count <= 1 || min < 0) return;
    223 
    224     delete mRenderers[min];
    225     mRenderers[min] = NULL;
    226 
    227     // Also eliminate the caches for large glyphs, as they consume significant memory
    228     for (int i = 0; i < kGammaCount; ++i) {
    229         if (mRenderers[i]) {
    230             mRenderers[i]->flushLargeCaches();
    231         }
    232     }
    233 }
    234 
    235 FontRenderer* Lookup3GammaFontRenderer::getRenderer(Gamma gamma) {
    236     FontRenderer* renderer = mRenderers[gamma];
    237     if (!renderer) {
    238         renderer = new FontRenderer();
    239         mRenderers[gamma] = renderer;
    240         renderer->setGammaTable(&mGammaTable[gamma * 256]);
    241     }
    242     mRenderersUsageCount[gamma]++;
    243     return renderer;
    244 }
    245 
    246 FontRenderer& Lookup3GammaFontRenderer::getFontRenderer(const SkPaint* paint) {
    247     if (paint->getShader() == NULL) {
    248         const int l = luminance(paint);
    249 
    250         if (l <= mBlackThreshold) {
    251             return *getRenderer(kGammaBlack);
    252         } else if (l >= mWhiteThreshold) {
    253             return *getRenderer(kGammaWhite);
    254         }
    255     }
    256     return *getRenderer(kGammaDefault);
    257 }
    258 
    259 }; // namespace uirenderer
    260 }; // namespace android
    261