Home | History | Annotate | Download | only in hwui 
      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 "Program.h"
     20 
     21 namespace android {
     22 namespace uirenderer {
     23 
     24 ///////////////////////////////////////////////////////////////////////////////
     25 // Base program
     26 ///////////////////////////////////////////////////////////////////////////////
     27 
     28 Program::Program(const char* vertex, const char* fragment) {
     29     mInitialized = false;
     30 
     31     vertexShader = buildShader(vertex, GL_VERTEX_SHADER);
     32     if (vertexShader) {
     33 
     34         fragmentShader = buildShader(fragment, GL_FRAGMENT_SHADER);
     35         if (fragmentShader) {
     36 
     37             id = glCreateProgram();
     38             glAttachShader(id, vertexShader);
     39             glAttachShader(id, fragmentShader);
     40             glLinkProgram(id);
     41 
     42             GLint status;
     43             glGetProgramiv(id, GL_LINK_STATUS, &status);
     44             if (status != GL_TRUE) {
     45                 LOGE("Error while linking shaders:");
     46                 GLint infoLen = 0;
     47                 glGetProgramiv(id, GL_INFO_LOG_LENGTH, &infoLen);
     48                 if (infoLen > 1) {
     49                     GLchar log[infoLen];
     50                     glGetProgramInfoLog(id, infoLen, 0, &log[0]);
     51                     LOGE("%s", log);
     52                 }
     53                 glDeleteShader(vertexShader);
     54                 glDeleteShader(fragmentShader);
     55                 glDeleteProgram(id);
     56             } else {
     57                 mInitialized = true;
     58             }
     59         }
     60     }
     61 
     62     mUse = false;
     63 
     64     if (mInitialized) {
     65         position = addAttrib("position");
     66         transform = addUniform("transform");
     67     }
     68 }
     69 
     70 Program::~Program() {
     71     if (mInitialized) {
     72         glDeleteShader(vertexShader);
     73         glDeleteShader(fragmentShader);
     74         glDeleteProgram(id);
     75     }
     76 }
     77 
     78 int Program::addAttrib(const char* name) {
     79     int slot = glGetAttribLocation(id, name);
     80     attributes.add(name, slot);
     81     return slot;
     82 }
     83 
     84 int Program::getAttrib(const char* name) {
     85     ssize_t index = attributes.indexOfKey(name);
     86     if (index >= 0) {
     87         return attributes.valueAt(index);
     88     }
     89     return addAttrib(name);
     90 }
     91 
     92 int Program::addUniform(const char* name) {
     93     int slot = glGetUniformLocation(id, name);
     94     uniforms.add(name, slot);
     95     return slot;
     96 }
     97 
     98 int Program::getUniform(const char* name) {
     99     ssize_t index = uniforms.indexOfKey(name);
    100     if (index >= 0) {
    101         return uniforms.valueAt(index);
    102     }
    103     return addUniform(name);
    104 }
    105 
    106 GLuint Program::buildShader(const char* source, GLenum type) {
    107     GLuint shader = glCreateShader(type);
    108     glShaderSource(shader, 1, &source, 0);
    109     glCompileShader(shader);
    110 
    111     GLint status;
    112     glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
    113     if (status != GL_TRUE) {
    114         // Some drivers return wrong values for GL_INFO_LOG_LENGTH
    115         // use a fixed size instead
    116         GLchar log[512];
    117         glGetShaderInfoLog(shader, sizeof(log), 0, &log[0]);
    118         LOGE("Error while compiling shader: %s", log);
    119         glDeleteShader(shader);
    120         return 0;
    121     }
    122 
    123     return shader;
    124 }
    125 
    126 void Program::set(const mat4& projectionMatrix, const mat4& modelViewMatrix,
    127         const mat4& transformMatrix, bool offset) {
    128     mat4 t(projectionMatrix);
    129     if (offset) {
    130         // offset screenspace xy by an amount that compensates for typical precision issues
    131         // in GPU hardware that tends to paint hor/vert lines in pixels shifted up and to the left.
    132         // This offset value is based on an assumption that some hardware may use as little
    133         // as 12.4 precision, so we offset by slightly more than 1/16.
    134         t.translate(.375, .375, 0);
    135     }
    136     t.multiply(transformMatrix);
    137     t.multiply(modelViewMatrix);
    138 
    139     glUniformMatrix4fv(transform, 1, GL_FALSE, &t.data[0]);
    140 }
    141 
    142 void Program::setColor(const float r, const float g, const float b, const float a) {
    143     glUniform4f(getUniform("color"), r, g, b, a);
    144 }
    145 
    146 void Program::use() {
    147     glUseProgram(id);
    148     mUse = true;
    149 
    150     glEnableVertexAttribArray(position);
    151 }
    152 
    153 void Program::remove() {
    154     mUse = false;
    155 
    156     glDisableVertexAttribArray(position);
    157 }
    158 
    159 }; // namespace uirenderer
    160 }; // namespace android
    161