1.OpenGL ES简介

OpenGL Es学习，首先要了解Android的基本架构，如下图：

在Android的第三层的Libraries里面就有OpenGL  ES库。OpenGL ES是一个跨平台的图形API，给3D图形处理硬件指定了一个标准的软件接口。

2.OpenGL ES在Android的使用

Android提供了两个类：GLSufaceView和GLSurfaceView.Renderer.

2.1GLSurfaceView

GlSurfaceView就是一个surfaceView ,只是增加了Render，用OpenGL来显示渲染。

2.2GLSurfaceView.Renderer

使用GLSurfaceView.setRenderer()将其附加到GLSurfaceView实例。

GLSurfaceView.Renderer要求实现以下方法：

• onSurfaceCreated()：创建GLSurfaceView时，系统调用一次该方法。使用此方法执行只需要执行一次的操作，例如设置OpenGL环境参数或初始化OpenGL图形对象。
• onDrawFrame()：系统在每次重画GLSurfaceView时调用这个方法。使用此方法作为绘制（和重新绘制）图形对象的主要执行方法。
• onSurfaceChanged()：当GLSurfaceView的发生变化时，系统调用此方法，这些变化包括GLSurfaceView的大小或设备屏幕方向的变化。例如：设备从纵向变为横向时，系统调用此方法。我们应该使用此方法来响应GLSurfaceView容器的改变。

使用GlSurfaceView步骤：

1. 创建一个GlSurfaceView。
2. 设置渲染
3. 在GlSurfaceView.renderder中绘制处理显示数据

3.OpenGL ES绘制图形

在Android使用OpenGL ES的步骤：

1. 在Manifest中声明OpenGL ES使用，我使用OpenGL ES2.0的API

   如果要使用问了要是添加

    

2. 设置相关的渲染Renderer，Renderer有三个方法：

• onSurfaceCreated() - 在View的OpenGL环境被创建的时候调用。
• onDrawFrame() - 每一次View的重绘都会调用
• onSurfaceChanged() - 如果视图的几何形状发生变化（例如，当设备的屏幕方向改变时），则调用此方法。

绘制图形

示例代码：

public class GlSurfaceViewActivity extends AppCompatActivity {private GLSurfaceView gLsurfaceview;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_gl_surface_view);        gLsurfaceview = findViewById(R.id.gLsurfaceview);        gLsurfaceview.setEGLContextClientVersion(2);       // gLsurfaceview.setRenderer(new Trianglerenderer());//三角形        //gLsurfaceview.setRenderer(new SquareRenderer());//正方形        gLsurfaceview.setRenderer(new CircleRenderer());//圆        gLsurfaceview.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);    }    @Override    protected void onResume() {        super.onResume(); gLsurfaceview.onResume();    }    @Override    protected void onPause() {        super.onPause();        gLsurfaceview.onPause();    }}

三角形的Renderer:

public class Trianglerenderer extends BackgroundRender {    private int mProgram;    private FloatBuffer vertexBuffer;    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;" +                    "}";    static float triangleCoords[] = {            0.0f,  0.6f, 0.0f, // top            -0.5f, -0.3f, 0.0f, // bottom left            0.5f, -0.3f, 0.0f  // bottom right    };    //设置颜色，依次为红绿蓝和透明通道    float color[] = { 0.0f, 1.0f, 0.0f, 1.0f ,            1.0f, 0.0f, 0.0f, 1.0f,            0.0f, 0.0f, 1.0f, 1.0f };    static final int COORDS_PER_VERTEX = 3;    private int mPositionHandle;    private int mColorHandle;    //顶点个数    private final int vertexCount = triangleCoords.length / COORDS_PER_VERTEX;    //顶点之间的偏移量    private final int vertexStride = COORDS_PER_VERTEX * 4; // 每个顶点四个字节    @Override    public void onSurfaceCreated(GL10 gl10, EGLConfig eglConfig) {        //将背景设置为灰色        GLES20.glClearColor(0.5f,0.5f,0.5f,1.0f);        //申请底层空间        ByteBuffer bb = ByteBuffer.allocateDirect(triangleCoords.length * 4);        bb.order(ByteOrder.nativeOrder());        //将坐标数据转换为FloatBuffer，用以传入OpenGL ES程序        vertexBuffer = bb.asFloatBuffer();        vertexBuffer.put(triangleCoords);        vertexBuffer.position(0);        int vertexShader =  loadShader(GLES20.GL_VERTEX_SHADER,vertexShaderCode);        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER,fragmentShaderCode);        //创建一个空的OpenGLES程序        mProgram = GLES20.glCreateProgram();        //将顶点着色器加入到程序        GLES20.glAttachShader(mProgram,vertexShader);        //将片元着色器加入到程序中        GLES20.glAttachShader(mProgram,fragmentShader);        //连接到着色器程序        GLES20.glLinkProgram(mProgram);    }    @Override    public void onSurfaceChanged(GL10 gl10, int width, int height) {        GLES20.glViewport(0,0,width,height);    }    @Override    public void onDrawFrame(GL10 gl10) {        //将程序加入到OpenGLES2.0环境        GLES20.glUseProgram(mProgram);        //获取顶点着色器的vPosition成员句柄        mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");        //启用三角形顶点的句柄        GLES20.glEnableVertexAttribArray(mPositionHandle);        //准备三角形的坐标数据        GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,                GLES20.GL_FLOAT, false,                vertexStride, vertexBuffer);        //获取片元着色器的vColor成员的句柄        mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");        //设置绘制三角形的颜色        GLES20.glUniform4fv(mColorHandle, 1, color, 0);        //绘制三角形        GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vertexCount);        //禁止顶点数组的句柄        GLES20.glDisableVertexAttribArray(mPositionHandle);    }}

正方形的Renderer：

public class SquareRenderer extends BackgroundRender implements GLSurfaceView.Renderer {    private FloatBuffer vertexBuffer;    private ShortBuffer indexBuffer;    private final String vertexShaderCode =            "attribute vec4 vPosition;" +                    "uniform mat4 vMatrix;" +                    "void main() {" +                    "  gl_Position = vMatrix*vPosition;" +                    "}";    private final String fragmentShaderCode =            "precision mediump float;" +                    "uniform vec4 vColor;" +                    "void main() {" +                    "  gl_FragColor = vColor;" +                    "}";    private int mProgram;    static final int COORDS_PER_VERTEX = 3;    static float triangleCoords[] = {            -0.5f, 0.5f, 0.0f, // top left            -0.5f, -0.5f, 0.0f, // bottom left            0.5f, -0.5f, 0.0f, // bottom right            0.5f, 0.5f, 0.0f  // top right    };    static short index[] = {            0, 1, 2, 0, 2, 3    };    private int mPositionHandle;    private int mColorHandle;    private float[] mViewMatrix = new float[16];    private float[] mProjectMatrix = new float[16];    private float[] mMVPMatrix = new float[16];    //顶点个数    private final int vertexCount = triangleCoords.length / COORDS_PER_VERTEX;    //顶点之间的偏移量    private final int vertexStride = COORDS_PER_VERTEX * 4; // 每个顶点四个字节    private int mMatrixHandler;    //设置颜色，依次为红绿蓝和透明通道    float color[] = {0.0f, 1.0f, 0.0f, 1.0f ,            1.0f, 0.0f, 0.0f, 1.0f,            0.0f, 0.0f, 1.0f, 1.0f};    @Override    public void onSurfaceCreated(GL10 gl10, EGLConfig eglConfig) {        ByteBuffer bb = ByteBuffer.allocateDirect(                triangleCoords.length * 4);        bb.order(ByteOrder.nativeOrder());        vertexBuffer = bb.asFloatBuffer();        vertexBuffer.put(triangleCoords);        vertexBuffer.position(0);        ByteBuffer cc = ByteBuffer.allocateDirect(index.length * 2);        cc.order(ByteOrder.nativeOrder());        indexBuffer = cc.asShortBuffer();        indexBuffer.put(index);        indexBuffer.position(0);        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER,                vertexShaderCode);        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER,                fragmentShaderCode);        //创建一个空的OpenGLES程序        mProgram = GLES20.glCreateProgram();        //将顶点着色器加入到程序        GLES20.glAttachShader(mProgram, vertexShader);        //将片元着色器加入到程序中        GLES20.glAttachShader(mProgram, fragmentShader);        //连接到着色器程序        GLES20.glLinkProgram(mProgram);    }    @Override    public void onSurfaceChanged(GL10 gl10, int width, int height) {        //计算宽高比        float ratio = (float) width / height;        //设置透视投影        Matrix.frustumM(mProjectMatrix, 0, -ratio, ratio, -1, 1, 3, 7);        //设置相机位置        Matrix.setLookAtM(mViewMatrix, 0, 0, 0, 7.0f, 0f, 0f, 0f, 0f, 1.0f, 0.0f);        //计算变换矩阵        Matrix.multiplyMM(mMVPMatrix, 0, mProjectMatrix, 0, mViewMatrix, 0);    }    @Override    public void onDrawFrame(GL10 gl10) {        //将程序加入到OpenGLES2.0环境        GLES20.glUseProgram(mProgram);        //获取变换矩阵vMatrix成员句柄        mMatrixHandler = GLES20.glGetUniformLocation(mProgram, "vMatrix");        //指定vMatrix的值        GLES20.glUniformMatrix4fv(mMatrixHandler, 1, false, mMVPMatrix, 0);        //获取顶点着色器的vPosition成员句柄        mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");        //启用三角形顶点的句柄        GLES20.glEnableVertexAttribArray(mPositionHandle);        //准备三角形的坐标数据        GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,                GLES20.GL_FLOAT, false,                vertexStride, vertexBuffer);        //获取片元着色器的vColor成员的句柄        mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");        //设置绘制三角形的颜色        GLES20.glUniform4fv(mColorHandle, 1, color, 0);        //绘制三角形//        GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, vertexCount);        //索引法绘制正方形        GLES20.glDrawElements(GLES20.GL_TRIANGLES, index.length, GLES20.GL_UNSIGNED_SHORT, indexBuffer);        //禁止顶点数组的句柄        GLES20.glDisableVertexAttribArray(mPositionHandle);    }}

圆的Renderer：

public class CircleRenderer extends BackgroundRender implements GLSurfaceView.Renderer {    String vertexShaderCode = "attribute vec4 vPosition;\n" +            "uniform mat4 vMatrix;\n" +            "void main() {\n" +            "  gl_Position = vMatrix*vPosition;\n" +            "}" ;    String fragmentShaderCode = "precision mediump float;\n" +            " uniform vec4 vColor;\n" +            " void main() {\n" +            "     gl_FragColor = vColor;\n" +            " }";    int mProgram;    private FloatBuffer vertexBuffer;    private float[] circlrCoods;    float color[] = { 1.0f, 1.0f, 1.0f, 1.0f }; //顶点统一白色    public CircleRenderer() {        //设置所有坐标        circlrCoods = createPositions();        //float[] → FloatBuffer        ByteBuffer bb = ByteBuffer.allocateDirect(circlrCoods.length * 4);        bb.order(ByteOrder.nativeOrder());        vertexBuffer = bb.asFloatBuffer();        vertexBuffer.put(circlrCoods);        vertexBuffer.position(0);    }    private float[]  createPositions(){        ArrayList data=new ArrayList<>();        data.add(0.0f);             //设置圆心坐标        data.add(0.0f);        data.add(0.0f);        //分成100条边，绘制出来应该很像圆了        float radius = 0.5f; //半径1        float angDegSpan=360f/100; //依次递加的角度        for(float i=0;i<360+angDegSpan;i+=angDegSpan){            data.add((float)(radius*Math.cos(i*Math.PI/180f))); //x            data.add((float) (radius*Math.sin(i*Math.PI/180f))); //y            data.add(0.0f); //z        }        float[] f=new float[data.size()];        for (int i=0;i


项目地址：https://github.com/ChloeDimen/AudioAndVideo