MyGLSurfaceView.java
public class MyGLSurfaceView extends GLSurfaceView {
public MyGLSurfaceView(Context context) {
super(context);
initView();
}
private void initView() {
setEGLContextClientVersion(2);
MultisampleConfigChooser eglConfigChooser = new MultisampleConfigChooser();
setEGLConfigChooser(eglConfigChooser);
setRenderer(new MyRender());
setRenderMode(RENDERMODE_WHEN_DIRTY);
}
}
MyRender.java
package com.example.baidu.opengl;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.util.Log;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
/**
* Created by baidu on 15/9/15.
*/
public class MyRender implements GLSurfaceView.Renderer {
private Triangle mTriangle;
@Override public void onSurfaceCreated(GL10 gl, EGLConfig config) {
GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1f);//清空当前的所有颜色
mTriangle = new Triangle();
}
@Override public void onSurfaceChanged(GL10 gl, int width, int height) {
GLES20.glViewport(0, 0, width, height);
float ratio = (float) width / height;
MatrixState.setProjectOrtho(-ratio, ratio, -1f, 1f, 1, 10);
MatrixState.setCamera(0.0f, 0.0f, 3.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f);
MatrixState.initMatrix();
}
@Override public void onDrawFrame(GL10 gl) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);//清除颜色缓冲
mTriangle.draw2();
}
/**
* 绘制一个形状
* 使用OpenGL ES 2.0绘制一个定义好的形状需要大量的代码，因为必须提供给图形渲染管道很多细节信息。具体定义如下：
* 1VertexShader：用于呈现形状顶点的OpenGL ES图形代码。
* 2FragmentShader：用于呈现形状外观（颜色或纹理）的OpenGL ES代码。
* 3Program：一个OpenGL ES对象，包含了你想要用来绘制一个或多个形状的shader。
* 你至少需要一个vertex shader来绘制一个形状和一个fragment shader来为形状着色。这些shader必须被编译，然后将它们添加到一个OpenGL ES program中，接着使用program绘制形状。
**/
/**
* 用于呈现顶点形状的ShaderCode
*
*/
private final String vertexShaderCode = "uniform mat4 uMVPMatrix; " +
"attribute vec3 aPosition;" +
"attribute vec2 aTexCoor; " +
"varying vec2 vTextureCoord; " +
"attribute vec4 aColor; " +
"varying vec4 vColor; " +
"void main() " +
"{" +
" gl_Position = uMVPMatrix * vec4(aPosition,1); " +
" vTextureCoord = aTexCoor;" +
" gl_PointSize=10.0;" +
" vColor = aColor;" +
"}";
private final String fragmentShaderCode = "precision mediump float;" +
"uniform int uIsColorFrag;" +
"uniform sampler2D sTexture;" +
"varying vec2 vTextureCoord;" +
"varying vec4 vColor;" +
"void main()" +
"{if(uIsColorFrag==1)" +
"{gl_FragColor = vColor;}" +
"else{gl_FragColor = texture2D(sTexture, vTextureCoord); }}";
// private final String vertexShaderCode = "attribute vec4 vPosition;" +
// "void main() {" +
// " gl_Position = vPosition;" +
// "}";
//
// private final String fragmentShaderCode = "precision mediump float;" +
// "uniform vec4 vColor;" +
// "void main() {" +
// " gl_FragColor = vColor;" +
// "}";
private int loadShader(int type, String shaderCode) {
// 创建一个vertex shader类型(GLES20.GL_VERTEX_SHADER)
// 或一个fragment shader类型(GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// 将源码添加到shader并编译它
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
class Triangle {
private final String TAG = Triangle.class.getSimpleName();
private FloatBuffer vertexBuffer;//顶点的buffer
private FloatBuffer colorsBuffer;//颜色的buffer
// 设置每个顶点的坐标数
static final int COORDS_PER_VERTEX = 3;
// 设置三角形顶点数组
final float triangleCoords[] = { // 默认按逆时针方向顺序绘制
0.0f, 0.622008459f, 0.0f, // 顶
-0.5f, -0.311004243f, 0.0f, // 左底
0.5f, -0.311004243f, 0.0f // 右底
};
// 设置图形的RGB值和透明度
float color[] =
{ 0.63671875f, 0.76953125f, 0.22265625f, 1.0f, 0.63671875f, 0.76953125f, 0.22265625f, 1.0f, 0.63671875f,
0.76953125f, 0.22265625f, 1.0f, 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
private int mPositionHandle;
private int mColorHandle;
/**
* 总变换矩阵位置
*/
protected int mUMvpMatrixLocation;
/**
* 顶点位置
*/
protected int mAPositionLocation;
/**
* 顶点颜色位置
*/
protected int mAColorLocation;
protected int mProgram;
/**
* 纹理的参数
*/
protected int isColorFrag;
/**
* 纹理
*/
protected int mATexCoor;
public Triangle() {
initShader();
// 初始化顶点字节缓冲区，用于存放形状的坐标，
ByteBuffer bb = ByteBuffer.allocateDirect(
// (每个浮点数占用4个字节)
triangleCoords.length * 4);
// 设置使用设备硬件的原生字节序
bb.order(ByteOrder.nativeOrder());
// 从ByteBuffer中创建一个浮点缓冲区
vertexBuffer = bb.asFloatBuffer();
// 把坐标都添加到FloatBuffer中
vertexBuffer.put(triangleCoords);
// 设置buffer从第一个坐标开始读
vertexBuffer.position(0);
ByteBuffer bBuffer = ByteBuffer.allocateDirect(color.length * 4);
bBuffer.order(ByteOrder.nativeOrder());
colorsBuffer = bBuffer.asFloatBuffer();
colorsBuffer.clear();
colorsBuffer.put(color);
colorsBuffer.position(0);
}
private void initShader() {
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // 创建空的OpenGL ES Program
GLES20.glAttachShader(mProgram, vertexShader); // 将vertex shader添加到program
GLES20.glAttachShader(mProgram, fragmentShader); // 将fragment shader添加到program
GLES20.glLinkProgram(mProgram); // 创建可执行的 OpenGL ES program
//存放链接成功program数量的数组
int[] linkStatus = new int[1];
//获取program的链接情况
GLES20.glGetProgramiv(mProgram, GLES20.GL_LINK_STATUS, linkStatus, 0);
//若链接失败则报错并删除程序
if (linkStatus[0] != GLES20.GL_TRUE) {
Log.e(TAG, "Could not link program: ");
Log.e(TAG, GLES20.glGetProgramInfoLog(mProgram));
GLES20.glDeleteProgram(mProgram);
mProgram = 0;
}
mAPositionLocation = GLES20.glGetAttribLocation(mProgram, "aPosition");
mAColorLocation = GLES20.glGetAttribLocation(mProgram, "aColor");
mUMvpMatrixLocation = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
isColorFrag = GLES20.glGetUniformLocation(mProgram, "uIsColorFrag");
mATexCoor = GLES20.glGetAttribLocation(mProgram, "aTexCoor");
}
public void draw2() {
GLES20.glUseProgram(mProgram);
GLES20.glUniformMatrix4fv(mUMvpMatrixLocation, 1, false, MatrixState.getFinalMatrix(), 0);
GLES20.glVertexAttribPointer(mAPositionLocation, 3, GLES20.GL_FLOAT, false, 3 * 4, vertexBuffer);
GLES20.glVertexAttribPointer(mAColorLocation, 4, GLES20.GL_FLOAT, false, 4 * 4, colorsBuffer);
GLES20.glEnableVertexAttribArray(mAPositionLocation);
GLES20.glEnableVertexAttribArray(mAColorLocation);
GLES20.glLineWidth(1);
GLES20.glDrawArrays(GLES20.GL_POINTS, 0, COORDS_PER_VERTEX);
GLES20.glDisableVertexAttribArray(mAPositionLocation);
GLES20.glDisableVertexAttribArray(mAColorLocation);
}
/**
*
*/
public void draw() {
// 添加program到OpenGL ES环境中
GLES20.glUseProgram(mProgram);
// 获取指向vertex shader的成员vPosition的handle
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
// 启用一个指向三角形的顶点数组的handle
GLES20.glEnableVertexAttribArray(mPositionHandle);
// 准备三角形的坐标数据
/**
void glVertexAttribPointer (int index, int size, int type, boolean normalized, int stride, Buffer ptr )
index 指定要修改的顶点着色器中顶点变量id；
size 指定每个顶点属性的组件数量。必须为1、2、3或者4。如position是由3个（x,y,z）组成，而颜色是4个（r,g,b,a））；
type 指定数组中每个组件的数据类型。可用的符号常量有GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT,GL_UNSIGNED_SHORT, GL_FIXED, 和 GL_FLOAT，初始值为GL_FLOAT；
normalized 指定当被访问时，固定点数据值是否应该被归一化（GL_TRUE）或者直接转换为固定点值（GL_FALSE）；
stride 指定连续顶点属性之间的偏移量。如果为0，那么顶点属性会被理解为：它们是紧密排列在一起的。初始值为0。如果normalized被设置为GL_TRUE，意味着整数型的值会被映射至区间[-1,1](有符号整数)，或者区间[0,1]（无符号整数），反之，这些值会被直接转换为浮点值而不进行归一化处理；
ptr 顶点的缓冲数据。
**/
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, 0, vertexBuffer);
// 获取指向fragment shader的成员vColor的handle
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
// 设置三角形的颜色
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
// 绘制三角形
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, COORDS_PER_VERTEX);
// 禁用指向三角形的顶点数组
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
}
}