package com.baidu.facelibrary.gl;
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import android.opengl.GLES20;
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import java.nio.ByteBuffer;
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import java.nio.ByteOrder;
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import java.nio.FloatBuffer;
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public class Shape {
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public Shape() {
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initializeBuffers();
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initializeProgram();
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}
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private float vertices[] = {
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-1f, -1f,
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1f, -1f,
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-1f, 1f,
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1f, 1f,
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};
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private float textureVertices[] = {
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0f, 1f,
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1f, 1f,
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0f, 0f,
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1f, 0f
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};
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private final String vertexShaderCode =
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"attribute vec4 aPosition;" +
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"attribute vec2 aTexPosition;" +
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"varying vec2 vTexPosition;" +
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"void main() {" +
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" gl_Position = aPosition;" +
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" vTexPosition = aTexPosition;" +
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"}";
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private final String fragmentShaderCode =
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"precision mediump float;" +
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"uniform sampler2D uTexture;" +
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"varying vec2 vTexPosition;" +
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"void main() {" +
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" gl_FragColor = texture2D(uTexture, vTexPosition);" +
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"}";
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private FloatBuffer verticesBuffer;
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private FloatBuffer textureBuffer;
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private int vertexShader;
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private int fragmentShader;
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private int program;
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private void initializeBuffers() {
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ByteBuffer buff = ByteBuffer.allocateDirect(vertices.length * 4);
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buff.order(ByteOrder.nativeOrder());
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verticesBuffer = buff.asFloatBuffer();
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verticesBuffer.put(vertices);
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verticesBuffer.position(0);
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buff = ByteBuffer.allocateDirect(textureVertices.length * 4);
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buff.order(ByteOrder.nativeOrder());
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textureBuffer = buff.asFloatBuffer();
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textureBuffer.put(textureVertices);
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textureBuffer.position(0);
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}
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private void initializeProgram() {
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vertexShader = GLES20.glCreateShader(GLES20.GL_VERTEX_SHADER);
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GLES20.glShaderSource(vertexShader, vertexShaderCode);
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GLES20.glCompileShader(vertexShader);
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fragmentShader = GLES20.glCreateShader(GLES20.GL_FRAGMENT_SHADER);
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GLES20.glShaderSource(fragmentShader, fragmentShaderCode);
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GLES20.glCompileShader(fragmentShader);
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program = GLES20.glCreateProgram();
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GLES20.glAttachShader(program, vertexShader);
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GLES20.glAttachShader(program, fragmentShader);
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GLES20.glLinkProgram(program);
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}
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public void draw(int texture) {
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GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
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GLES20.glUseProgram(program);
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GLES20.glDisable(GLES20.GL_BLEND);
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int positionHandle = GLES20.glGetAttribLocation(program, "aPosition");
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int textureHandle = GLES20.glGetUniformLocation(program, "uTexture");
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int texturePositionHandle = GLES20.glGetAttribLocation(program, "aTexPosition");
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GLES20.glVertexAttribPointer(texturePositionHandle, 2, GLES20.GL_FLOAT, false, 0, textureBuffer);
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GLES20.glEnableVertexAttribArray(texturePositionHandle);
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GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
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GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture);
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GLES20.glUniform1i(textureHandle, 0);
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GLES20.glVertexAttribPointer(positionHandle, 2, GLES20.GL_FLOAT, false, 0, verticesBuffer);
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GLES20.glEnableVertexAttribArray(positionHandle);
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GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
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GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
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}
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}
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