Program.cpp revision 98173a277f8bd6d53d6ff9f7ff09e084f2666fc1 
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            char* log = (char*) malloc(sizeof(char) * infoLen);
50            glGetProgramInfoLog(id, infoLen, 0, log);
51            LOGE("Error while linking shaders: %s", log);
52            delete log;
53        }
54        glDeleteShader(vertexShader);
55        glDeleteShader(fragmentShader);
56        glDeleteProgram(id);
57    }
58
59    mUse = false;
60
61    position = addAttrib("position");
62    color = addUniform("color");
63    transform = addUniform("transform");
64}
65
66Program::~Program() {
67    glDeleteShader(vertexShader);
68    glDeleteShader(fragmentShader);
69    glDeleteProgram(id);
70}
71
72int Program::addAttrib(const char* name) {
73    int slot = glGetAttribLocation(id, name);
74    attributes.add(name, slot);
75    return slot;
76}
77
78int Program::getAttrib(const char* name) {
79    ssize_t index = attributes.indexOfKey(name);
80    if (index >= 0) {
81        return attributes.valueAt(index);
82    }
83    return addAttrib(name);
84}
85
86int Program::addUniform(const char* name) {
87    int slot = glGetUniformLocation(id, name);
88    uniforms.add(name, slot);
89    return slot;
90}
91
92int Program::getUniform(const char* name) {
93    ssize_t index = uniforms.indexOfKey(name);
94    if (index >= 0) {
95        return uniforms.valueAt(index);
96    }
97    return addUniform(name);
98}
99
100GLuint Program::buildShader(const char* source, GLenum type) {
101    GLuint shader = glCreateShader(type);
102    glShaderSource(shader, 1, &source, 0);
103    glCompileShader(shader);
104
105    GLint status;
106    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
107    if (status != GL_TRUE) {
108        // Some drivers return wrong values for GL_INFO_LOG_LENGTH
109        // use a fixed size instead
110        GLchar log[512];
111        glGetShaderInfoLog(shader, sizeof(log), 0, &log[0]);
112        LOGE("Error while compiling shader: %s", log);
113        glDeleteShader(shader);
114    }
115
116    return shader;
117}
118
119void Program::set(const mat4& projectionMatrix, const mat4& modelViewMatrix,
120        const mat4& transformMatrix) {
121    mat4 t(projectionMatrix);
122    t.multiply(transformMatrix);
123    t.multiply(modelViewMatrix);
124
125    glUniformMatrix4fv(transform, 1, GL_FALSE, &t.data[0]);
126}
127
128void Program::use() {
129    glUseProgram(id);
130    mUse = true;
131
132    glEnableVertexAttribArray(position);
133}
134
135void Program::remove() {
136    mUse = false;
137
138    glDisableVertexAttribArray(position);
139}
140
141}; // namespace uirenderer
142}; // namespace android
143