Home | History | Annotate | Download | only in RenderEngine 
      1 /*
      2  * Copyright 2013 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 <GLES/gl.h>
     18 
     19 #include <cutils/compiler.h>
     20 
     21 #include "GLES10RenderEngine.h"
     22 
     23 // ---------------------------------------------------------------------------
     24 namespace android {
     25 // ---------------------------------------------------------------------------
     26 
     27 GLES10RenderEngine::~GLES10RenderEngine() {
     28 }
     29 
     30 void GLES10RenderEngine::setupLayerBlending(
     31 #ifdef USE_HWC2
     32     bool premultipliedAlpha, bool opaque, float alpha) {
     33 #else
     34     bool premultipliedAlpha, bool opaque, int alpha) {
     35 #endif
     36     // OpenGL ES 1.0 doesn't support texture combiners.
     37     // This path doesn't properly handle opaque layers that have non-opaque
     38     // alpha values. The alpha channel will be copied into the framebuffer or
     39     // screenshot, so if the framebuffer or screenshot is blended on top of
     40     // something else,  whatever is below the window will incorrectly show
     41     // through.
     42 #ifdef USE_HWC2
     43     if (CC_UNLIKELY(alpha < 1.0f)) {
     44         if (premultipliedAlpha) {
     45             glColor4f(alpha, alpha, alpha, alpha);
     46         } else {
     47             glColor4f(1.0f, 1.0f, 1.0f, alpha);
     48         }
     49 #else
     50     if (CC_UNLIKELY(alpha < 0xFF)) {
     51         GLfloat floatAlpha = alpha * (1.0f / 255.0f);
     52         if (premultipliedAlpha) {
     53             glColor4f(floatAlpha, floatAlpha, floatAlpha, floatAlpha);
     54         } else {
     55             glColor4f(1.0f, 1.0f, 1.0f, floatAlpha);
     56         }
     57 #endif
     58         glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
     59     } else {
     60         glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
     61     }
     62 
     63 #ifdef USE_HWC2
     64     if (alpha < 1.0f || !opaque) {
     65 #else
     66     if (alpha < 0xFF || !opaque) {
     67 #endif
     68         glEnable(GL_BLEND);
     69         glBlendFunc(premultipliedAlpha ? GL_ONE : GL_SRC_ALPHA,
     70                     GL_ONE_MINUS_SRC_ALPHA);
     71     } else {
     72         glDisable(GL_BLEND);
     73     }
     74 }
     75 
     76 // ---------------------------------------------------------------------------
     77 }; // namespace android
     78 // ---------------------------------------------------------------------------
     79