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(); } }