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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 // Constructors/destructor
     28 ///////////////////////////////////////////////////////////////////////////////
     29 
     30 GammaFontRenderer::GammaFontRenderer() {
     31     INIT_LOGD("Creating gamma font renderer");
     32 
     33     // Get the renderer properties
     34     char property[PROPERTY_VALUE_MAX];
     35 
     36     // Get the gamma
     37     float gamma = DEFAULT_TEXT_GAMMA;
     38     if (property_get(PROPERTY_TEXT_GAMMA, property, NULL) > 0) {
     39         INIT_LOGD("  Setting text gamma to %s", property);
     40         gamma = atof(property);
     41     } else {
     42         INIT_LOGD("  Using default text gamma of %.2f", DEFAULT_TEXT_GAMMA);
     43     }
     44 
     45     // Get the black gamma threshold
     46     mBlackThreshold = DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD;
     47     if (property_get(PROPERTY_TEXT_BLACK_GAMMA_THRESHOLD, property, NULL) > 0) {
     48         INIT_LOGD("  Setting text black gamma threshold to %s", property);
     49         mBlackThreshold = atoi(property);
     50     } else {
     51         INIT_LOGD("  Using default text black gamma threshold of %d",
     52                 DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD);
     53     }
     54 
     55     // Get the white gamma threshold
     56     mWhiteThreshold = DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD;
     57     if (property_get(PROPERTY_TEXT_WHITE_GAMMA_THRESHOLD, property, NULL) > 0) {
     58         INIT_LOGD("  Setting text white gamma threshold to %s", property);
     59         mWhiteThreshold = atoi(property);
     60     } else {
     61         INIT_LOGD("  Using default white black gamma threshold of %d",
     62                 DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD);
     63     }
     64 
     65     // Compute the gamma tables
     66     const float blackGamma = gamma;
     67     const float whiteGamma = 1.0f / gamma;
     68 
     69     for (uint32_t i = 0; i <= 255; i++) {
     70         mGammaTable[i] = i;
     71 
     72         const float v = i / 255.0f;
     73         const float black = pow(v, blackGamma);
     74         const float white = pow(v, whiteGamma);
     75 
     76         mGammaTable[256 + i] = uint8_t((float)::floor(black * 255.0f + 0.5f));
     77         mGammaTable[512 + i] = uint8_t((float)::floor(white * 255.0f + 0.5f));
     78     }
     79 
     80     memset(mRenderers, 0, sizeof(FontRenderer*) * kGammaCount);
     81     memset(mRenderersUsageCount, 0, sizeof(uint32_t) * kGammaCount);
     82 }
     83 
     84 GammaFontRenderer::~GammaFontRenderer() {
     85     for (int i = 0; i < kGammaCount; i++) {
     86         delete mRenderers[i];
     87     }
     88 }
     89 
     90 void GammaFontRenderer::clear() {
     91     for (int i = 0; i < kGammaCount; i++) {
     92         delete mRenderers[i];
     93         mRenderers[i] = NULL;
     94     }
     95 }
     96 
     97 void GammaFontRenderer::flush() {
     98     int count = 0;
     99     int min = -1;
    100     uint32_t minCount = UINT_MAX;
    101 
    102     for (int i = 0; i < kGammaCount; i++) {
    103         if (mRenderers[i]) {
    104             count++;
    105             if (mRenderersUsageCount[i] < minCount) {
    106                 minCount = mRenderersUsageCount[i];
    107                 min = i;
    108             }
    109         }
    110     }
    111 
    112     if (count <= 1 || min < 0) return;
    113 
    114     delete mRenderers[min];
    115     mRenderers[min] = NULL;
    116 }
    117 
    118 FontRenderer* GammaFontRenderer::getRenderer(Gamma gamma) {
    119     FontRenderer* renderer = mRenderers[gamma];
    120     if (!renderer) {
    121         renderer = new FontRenderer();
    122         mRenderers[gamma] = renderer;
    123         renderer->setGammaTable(&mGammaTable[gamma * 256]);
    124     }
    125     mRenderersUsageCount[gamma]++;
    126     return renderer;
    127 }
    128 
    129 FontRenderer& GammaFontRenderer::getFontRenderer(const SkPaint* paint) {
    130     if (paint->getShader() == NULL) {
    131         uint32_t c = paint->getColor();
    132         const int r = (c >> 16) & 0xFF;
    133         const int g = (c >>  8) & 0xFF;
    134         const int b = (c      ) & 0xFF;
    135         const int luminance = (r * 2 + g * 5 + b) >> 3;
    136 
    137         if (luminance <= mBlackThreshold) {
    138             return *getRenderer(kGammaBlack);
    139         } else if (luminance >= mWhiteThreshold) {
    140             return *getRenderer(kGammaWhite);
    141         }
    142     }
    143     return *getRenderer(kGammaDefault);
    144 }
    145 
    146 }; // namespace uirenderer
    147 }; // namespace android
    148