Android OpenGL ES（六）创建实例应用OpenGLDemos程序框架 .

有了前面关于Android OpenGL ES的介绍，可以开始创建示例程序OpenGLDemos。

使用Eclipse 创建一个Android项目

Project Name: OpenGLDemos
Build Target: Android 1.6 ( >1.5 即可）
Application Name: Android OpenGL ES Demos
Package Name: com.pstreets.opengl.demo
Create Activity:AndroidOpenGLDemo

创建一个OpenGLRenderer 实现 GLSurfaceView.Renderer接口：

OpenGLRenderer.java

package com.example.gltest;

import javax.microedition.khronos.opengles.GL10;

import android.opengl.EGLConfig;

import android.opengl.GLSurfaceView.Renderer;

import android.opengl.GLU;

public class OpenGLRenderer implements Renderer {

     private final IOpenGLDemo openGLDemo;

     public OpenGLRenderer(IOpenGLDemo demo){

     openGLDemo=demo;

     }

     public void onSurfaceCreated(GL10 gl, EGLConfig config) {

     // Set the background color to black ( rgba ).

     gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f);

     // Enable Smooth Shading, default not really needed.

     gl.glShadeModel(GL10.GL_SMOOTH);

     // Depth buffer setup.

     gl.glClearDepthf(1.0f);

     // Enables depth testing.

     gl.glEnable(GL10.GL_DEPTH_TEST);

     // The type of depth testing to do.

     gl.glDepthFunc(GL10.GL_LEQUAL);

     // Really nice perspective calculations.

     gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT,

     GL10.GL_NICEST);

     }

     public void onDrawFrame(GL10 gl) {

     if(openGLDemo!=null){

     openGLDemo.DrawScene(gl);

     }

     }

     public void onSurfaceChanged(GL10 gl, int width, int height) {

     // Sets the current view port to the new size.

     gl.glViewport(, , width, height);

     // Select the projection matrix

     gl.glMatrixMode(GL10.GL_PROJECTION);

     // Reset the projection matrix

     gl.glLoadIdentity();

     // Calculate the aspect ratio of the window

     GLU.gluPerspective(gl, 45.0f,

     (float) width / (float) height,

     0.1f, 100.0f);

     // Select the modelview matrix

     gl.glMatrixMode(GL10.GL_MODELVIEW);

     // Reset the modelview matrix

     gl.glLoadIdentity();

     }

    @Override

    public void onSurfaceCreated(GL10 arg0,

            javax.microedition.khronos.egl.EGLConfig arg1) {

        // TODO Auto-generated method stub

    }

    }

为简洁起见，为所有的示例定义了一个接口IOpenGLDemo，
定义在IOpenGLDemo.java

package com.example.gltest;

import javax.microedition.khronos.opengles.GL10;

public interface IOpenGLDemo {

     public void DrawScene(GL10 gl);

    }

DrawScene 用于实际的GL绘图示例代码，其它的初始化工作基本就由GLSurfaceView 和OpenGLRenderer 完成,其中onSurfaceCreated 和 onSurfaceChanged 中的代码含义现在无需了解，后面会有具体介绍，只要知道它们是用来初始化GLSurfaceView就可以了。

最后使用一个简单的例子“Hello World”结束本篇，“Hello World” 使用红色背景刷新屏幕。

MainActivity.java

package com.example.gltest;

import javax.microedition.khronos.opengles.GL10;

import android.opengl.GLSurfaceView;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.Window;

import android.view.WindowManager;

public class MainActivity extends Activity

       implements IOpenGLDemo{

        /** Called when the activity is first created. */

        @Override

        public void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            this.requestWindowFeature(Window.FEATURE_NO_TITLE);

            getWindow()

             .setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,

                WindowManager.LayoutParams.FLAG_FULLSCREEN);

            mGLSurfaceView = new GLSurfaceView(this);

            mGLSurfaceView.setRenderer(new OpenGLRenderer(this));

            setContentView(mGLSurfaceView);

        }

        public void DrawScene(GL10 gl) {

            gl.glClearColor(1.0f, 0.0f, 0.0f, 0.0f);

            // Clears the screen and depth buffer.

            gl.glClear(GL10.GL_COLOR_BUFFER_BIT

              | GL10.GL_DEPTH_BUFFER_BIT);

        }

        @Override

        protected void onResume() {

            // Ideally a game should implement

            // onResume() and onPause()

            // to take appropriate action when the

            //activity looses focus

            super.onResume();

            mGLSurfaceView.onResume();

        }

        @Override

        protected void onPause() {

            // Ideally a game should implement onResume()

            //and onPause()

            // to take appropriate action when the

            //activity looses focus

            super.onPause();

            mGLSurfaceView.onPause();

        }

        private GLSurfaceView mGLSurfaceView;

    }

结果如下：

Android OpenGL ES（六）创建实例应用OpenGLDemos程序框架 .