GLShaders.java

/*
 * Copyright (C) Winson Chiu
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cw.kop.autobackground;

import android.opengl.GLES20;

public class GLShaders {

    public static final String VERTEX_SHADER =
            "uniform mat4 uMVPMatrix;" +
            "attribute vec4 vPosition;" +
            "attribute vec2 aTexCoords;" +
            "varying vec2 vTexCoords;" +
            "void main() {" +
            "    gl_Position = uMVPMatrix * vPosition;" +
            "    vTexCoords = aTexCoords;" +
            "}";
    public static final String FRAGMENT_SHADER =
            "precision mediump float;" +
            "varying vec2 vTexCoords;" +
            "uniform float opacity;" +
            "uniform sampler2D sTexture;" +
            "void main() {" +
            "    gl_FragColor = texture2D(sTexture, vTexCoords);" +
            "    gl_FragColor.a *= opacity;" +
            "}";

    public static int loadShader(int type, String shaderCode) {

        // create a vertex shader type (GLES20.GL_VERTEX_SHADER)
        // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
        int shader = GLES20.glCreateShader(type);

        // add the source code to the shader and compile it
        GLES20.glShaderSource(shader, shaderCode);
        GLES20.glCompileShader(shader);

        // return the shader
        return shader;
    }
}