Program.cpp revision 31529ff7918ce891fba9a660d0a861eb313ea554 
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
21namespace android {
22namespace uirenderer {
23
24///////////////////////////////////////////////////////////////////////////////
25// Shaders
26///////////////////////////////////////////////////////////////////////////////
27
28#define SHADER_SOURCE(name, source) const char* name = #source
29
30///////////////////////////////////////////////////////////////////////////////
31// Base program
32///////////////////////////////////////////////////////////////////////////////
33
34Program::Program(const char* vertex, const char* fragment) {
35    vertexShader = buildShader(vertex, GL_VERTEX_SHADER);
36    fragmentShader = buildShader(fragment, GL_FRAGMENT_SHADER);
37
38    id = glCreateProgram();
39    glAttachShader(id, vertexShader);
40    glAttachShader(id, fragmentShader);
41    glLinkProgram(id);
42
43    GLint status;
44    glGetProgramiv(id, GL_LINK_STATUS, &status);
45    if (status != GL_TRUE) {
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("Error while linking shaders: %s", log);
52        }
53        glDeleteShader(vertexShader);
54        glDeleteShader(fragmentShader);
55        glDeleteProgram(id);
56    }
57
58    mUse = false;
59
60    position = addAttrib("position");
61    color = addUniform("color");
62    transform = addUniform("transform");
63}
64
65Program::~Program() {
66    glDeleteShader(vertexShader);
67    glDeleteShader(fragmentShader);
68    glDeleteProgram(id);
69}
70
71int Program::addAttrib(const char* name) {
72    int slot = glGetAttribLocation(id, name);
73    attributes.add(name, slot);
74    return slot;
75}
76
77int Program::getAttrib(const char* name) {
78    ssize_t index = attributes.indexOfKey(name);
79    if (index >= 0) {
80        return attributes.valueAt(index);
81    }
82    return addAttrib(name);
83}
84
85int Program::addUniform(const char* name) {
86    int slot = glGetUniformLocation(id, name);
87    uniforms.add(name, slot);
88    return slot;
89}
90
91int Program::getUniform(const char* name) {
92    ssize_t index = uniforms.indexOfKey(name);
93    if (index >= 0) {
94        return uniforms.valueAt(index);
95    }
96    return addUniform(name);
97}
98
99GLuint Program::buildShader(const char* source, GLenum type) {
100    GLuint shader = glCreateShader(type);
101    glShaderSource(shader, 1, &source, 0);
102    glCompileShader(shader);
103
104    GLint status;
105    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
106    if (status != GL_TRUE) {
107        // Some drivers return wrong values for GL_INFO_LOG_LENGTH
108        // use a fixed size instead
109        GLchar log[512];
110        glGetShaderInfoLog(shader, sizeof(log), 0, &log[0]);
111        LOGE("Error while compiling shader: %s", log);
112        glDeleteShader(shader);
113    }
114
115    return shader;
116}
117
118void Program::set(const mat4& projectionMatrix, const mat4& modelViewMatrix,
119        const mat4& transformMatrix) {
120    mat4 t(projectionMatrix);
121    t.multiply(transformMatrix);
122    t.multiply(modelViewMatrix);
123
124    glUniformMatrix4fv(transform, 1, GL_FALSE, &t.data[0]);
125}
126
127void Program::use() {
128    glUseProgram(id);
129    mUse = true;
130
131    glEnableVertexAttribArray(position);
132}
133
134void Program::remove() {
135    mUse = false;
136
137    glDisableVertexAttribArray(position);
138}
139
140}; // namespace uirenderer
141}; // namespace android
142