Android开发之绘制平面上的多边形功能分析

public class MyRenderer implements Renderer{ float[] triangleData = new float []{   0.1f,0.6f,0.0f,//上顶点   -0.3f,0.0f,0.0f,//左顶点   0.3f,0.1f,0.0f//右顶点 }; int[] triangleColor = new int []{   65535,0,0,0,//上顶点红色   0,65535,0,0,//左顶点绿色   0,0,65535,0//右顶点蓝色 }; float[] rectData = new float[]{   0.4f,0.4f,0.0f,//右上顶点   0.4f,-0.4f,0.0f,//右下顶点   -0.4f,0.4f,0.0f,//左上顶点   -0.4f,-0.4f,0.0f//左下顶点 }; int[] rectColor = new int []{   0,65535,0,0,//右上顶点绿色   0,0,65535,0,//右下顶点蓝色   65535,0,0,0,//左上顶点红色   65535,65535,0,0//左下顶点黄色 }; float[] rectData2 = new float[]{   -0.4f,0.4f,0.0f,//左上顶点   0.4f,0.4f,0.0f,   0.4f,-0.4f,0.0f,   -0.4f,-0.4f,0.0frectColorBuffer }; float[] pentacle = new float[]{   0.4f,0.4f,0.0f,   -0.2f,0.3f,0.0f,   0.5f,0.0f,0f,   -0.4f,0.0f,0f   -0.1f,-0.3f,0f }; FloatBuffer triangleDataBuffer; IntBuffer triangleColorBuffer; FloatBuffer rectDataBuffer; FloatBuffer rectDataBuffer2; FloatBuffer pentacleBuffer; IntBuffer rectDataBuffer; public MyRenderer() {  //将顶点位置数据数组包装成FloatBuffer；  triangleDataBuffer = FloatBuffer.wrap(triangleData);  rectDataBuffer =FloatBuffer.wrap(rectData);  rectDataBuffer2 =FloatBuffer.wrap(rectData2);  pentacleBuffer = FloatBuffer.wrap(pentacle);  //将顶点颜色数据数组包装成IntBuffer；  triangleColorBuffer=IntBuffer.wrap(triangleColor);  rectColorBuffer= IntBuffer.wrap(rectColor); }; //关闭抗抖动  gl.glDisable(GL10.GL_DITHER);  //设置系对透视进行修正  gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);  gl.glClearColor(0, 0, 0, 0);  //设置阴影平滑模式  gl.glShadeModel(GL10.GL_SMOOTH);  //启用深度测试  gl.glEnable(GL10.GL_DEPTH_TEST);  //设置深度测试的类型  gl.glDepthFunc(GL10.GL_LEQUAL); } public void onSurfaceChanged(GL10 gl,int width,int height) {  //设置3D视窗的大小和位置  gl.glViewport(0,0,width,height);  //将当前矩阵模式设为投影矩阵  gl.glMatrixMode(GL10.GL_PROJECTION);  //初始化单位矩阵  gl.glLoadIdentity();  //计算透视视窗的宽度、高度比  float ratio = (float)width/height;  //调用此方法设置透视视窗的空间大小  gl.glFrustumf(-ratio,ratio,-1,1,1,10); } public void onDrawFrame(GL10 gl) {  //清除屏幕缓存和深度缓存  gl.glClear(GL10.GL_COLOR_BUFFER_BIT|GL10.GL_DEPTH_BUFFER_BIT);  //启用顶点坐标数据  gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);  //启用顶点颜色数据  gl.glEnableClientState(GL10.GL_COLOR_ARRAY);  //设置当前矩阵堆栈为模型堆栈  gl.glMatrixMode(GL10.GL_MODELVIEW);  //绘制第一个图形，重置当前的模型视图矩阵  gl.glLoadIdentity();  gl.glTranslatef(-0.32f, 0.35f, -1f);  //设置顶点的位置数据  gl.glVertexPointer(3, GL10.GL_FLOAT, 0, triangleDataBuffer);  //设置顶点的颜色数据  gl.glColorPointer(4, GL10.GL_FIXED, 0, triangleColorBuffer);  //根据顶点数据绘制平面图形  gl.glDrawArrays(GL10.GL_TRIANGLES, 0, 3);  //绘制第二个图形  gl.glLoadIdentity();  gl.glTranslatef(0.6f, 0.8f, -1.5f);  gl.glVertexPointer(3, GL10.GL_FLOAT, 0, rectDataBuffer);  gl.glColorPointer(4, GL10.GL_FIXED, 0, rectColorBuffer);  gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP,0,4);  //绘制第三个图形  gl.glLoadIdentity();  gl.glTranslatef(-0.4f, -0.5f, -1.5f);  gl.glVertexPointer(3,GL10.GL_FLOAT, 0, rectDataBuffer2);  gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP,0,4);  //  gl.glLoadIdentity();  gl.glTranslatef(0.4f, -0.5f, -1.5f);  //设置使用纯色填充  gl.glColor4f(1.0f,0.2f,0.2f,0.0f);  gl.glDisableClientState(GL10.GL_COLOR_ARRAY);  gl.glVertexPointer(3, GL10.GL_FLOAT, 0,penTacleBuffer);  gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP,0,5);  //绘制结束  gl.glFinish();  gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); }}