OpenGL学习（1）基本概述

OpenGL学习（1）基本概述

(1)重写Rendar（渲染器）， 重写三个方法：

        a、onSurfaceCreated(GL10 gl, EGLConfig config);        b、onSurfaceChanged(GL10 gl, int width, int height);         c、 onDrawFrame(GL10 gl);

package com.example.mychapter2;import javax.microedition.khronos.egl.EGLConfig;import javax.microedition.khronos.opengles.GL10;import android.opengl.GLU;import android.opengl.GLSurfaceView.Renderer;public class GLRender implements Renderer{    public void onDrawFrame(GL10 gl)    {        // TODO Auto-generated method stub        // 首先清理屏幕        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);        // 设置模型视图矩阵        gl.glMatrixMode(GL10.GL_MODELVIEW);        // 重置矩阵        gl.glLoadIdentity();        // 视点变换        GLU.gluLookAt(gl, 0, 0, 3, 0, 0, 0, 0, 1, 0);        // ...    }    public void onSurfaceChanged(GL10 gl, int width, int height)    {        // TODO Auto-generated method stub        float ratio = (float) width / height;        // 设置视口(OpenGL场景的大小)        gl.glViewport(0, 0, width, height);        // 设置投影矩阵为透视投影        gl.glMatrixMode(GL10.GL_PROJECTION);        // 重置投影矩阵（置为单位矩阵）        gl.glLoadIdentity();        // 创建一个透视投影矩阵（设置视口大小）        gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);    }    public void onSurfaceCreated(GL10 gl, EGLConfig config)    {        // TODO Auto-generated method stub        // 告诉系统需要对透视进行修正        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);        // 设置清理屏幕的颜色        gl.glClearColor(0, 0, 0, 1);        // 启用深度缓存        gl.glEnable(GL10.GL_DEPTH_TEST);    }}

(2)创建一个GLSurfaceView

  (a)创建一个GLSurfaceView实例mGLSurfaceView，
  (b)设置渲染器mGLSurfaceView.setRenderer(Render);

package com.example.mychapter2;import android.app.Activity;import android.opengl.GLSurfaceView;import android.os.Bundle;public class ChapterMain extends Activity{    private GLSurfaceView mGLSurfaceView;    /** Called when the activity is first created. */    public void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        // 实例化GLSurfaceView        mGLSurfaceView = new GLSurfaceView(this);        // 设置渲染器        mGLSurfaceView.setRenderer(new GLRender());        setContentView(mGLSurfaceView);    }    protected void onResume()    {        super.onResume();        mGLSurfaceView.onResume();    }    protected void onPause()    {        super.onPause();        mGLSurfaceView.onPause();    }}