第五课 3D空间:
我们使用多边形和四边形创建3D物体，在这一课里，我们把三角形变为立体的金子塔形状，把四边形变为立方体。
先看看三角形的顶点变成啥了
private float[] mTriangleArray = { 0.0f,1.0f,0.0f, -1.0f,-1.0f,1.0f, 1.0f,-1.0f,1.0f, 0.0f,1.0f,0.0f, 1.0f,-1.0f,1.0f, 1.0f,-1.0f,-1.0f, 0.0f,1.0f,0.0f, 1.0f,-1.0f,-1.0f, -1.0f,-1.0f,-1.0f, 0.0f,1.0f,0.0f, -1.0f,-1.0f,-1.0f, -1.0f,-1.0f,1.0f }; private FloatBuffer mTriangleBuffer;
一个四个面，每个面三个点，地面没画。
你们仔细看看每个面，都是按逆时针方向画的。当然，如果你没有增加Cull剔除代码（上节课最后提到），至于顺时针，逆时针都无所谓，都画。但是我们还是推荐使用按照方向来写的array。
三角形的颜色数组来了
private float[] mColorArray={ 1.0f,0.0f,0.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, }; private FloatBuffer mColorBuffer;
注意，同一个点是同一个颜色。
立方体的顶点数组：（原文中没有）
// 四边形的顶点数组 private float[] mQuadsArray = { // 前 1f, 1f, 1f, // 右上 -1f, 1f, 1f, // 左上 -1f, -1f, 1f, // 左下 1f, -1f, 1f,// 右下 // 右 1f, 1f, -1f, // 右上 1f, 1f, 1f, // 左上 1f, -1f, 1f, // 左下 1f, -1f, -1f,// 右下 // 后 -1f, 1f, -1f, // 右上 1f, 1f, -1f, // 左上 1f, -1f, -1f, // 左下 -1f, -1f, -1f,// 右下 // 左 -1f, 1f, 1f, // 右上 -1f, 1f, -1f, // 左上 -1f, -1f, -1f, // 左下 -1f, -1f, 1f, // 右下 // 顶 1f, 1f, -1f, // 右上 -1f, 1f, -1f, // 左上 -1f, 1f, 1f, // 左下 1f, 1f, 1f, // 右下 // 底 1f, -1f, 1f, // 右上 -1f, -1f, 1f, // 左上 -1f, -1f, -1f, // 左下 1f, -1f, -1f // 右下 }; // 从这里可以看出，我们按照逆时针的方向画图 private FloatBuffer mQuadsBuffer;
立方体的颜色数组来了
private float[] mQuadColorArray={ 0.0f,1.0f,0.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, 0.0f,1.0f,0.0f,1.0f, 1.0f,0.5f,0.0f,1.0f, 1.0f,0.5f,0.0f,1.0f, 1.0f,0.5f,0.0f,1.0f, 1.0f,0.5f,0.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 1.0f,0.0f,0.0f,1.0f, 1.0f,1.0f,0.0f,1.0f, 1.0f,1.0f,0.0f,1.0f, 1.0f,1.0f,0.0f,1.0f, 1.0f,1.0f,0.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 0.0f,0.0f,1.0f,1.0f, 1.0f,0.0f,1.0f,1.0f, 1.0f,0.0f,1.0f,1.0f, 1.0f,0.0f,1.0f,1.0f, 1.0f,0.0f,1.0f,1.0f, }; private FloatBuffer mQuadColorBuffer;
不要晕，后面有了纹理就好了，不过这是基础，一定要掌握。
画图的代码来了
gl.glTranslatef(-1.5f, 0.0f, -6.0f); gl.glRotatef(rtri, 0.0f, 1.0f, 0.0f); //绕Y轴旋转 // gl.glColor4f(1f, 1f, 1f, 1f); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mTriangleBuffer); gl.glDrawArrays(GL10.GL_TRIANGLES, 0, 12); //四棱锥有4个面，每个面3个点 gl.glLoadIdentity(); gl.glTranslatef(1.5f, 0.0f, -6.0f); gl.glRotatef(rquad, 1.0f, 0.0f, 0.0f); // gl.glRotatef(rquad, 1.0f, -0.8f, 0.0f); // 斜着旋转 gl.glColorPointer(4, GL10.GL_FLOAT, 0, mQuadColorBuffer); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mQuadsBuffer); //依次画6个面 for (int i=0; i<6; i++){ gl.glDrawArrays(GL10.GL_TRIANGLE_FAN, i*4, 4); } rtri+=0.2f; rquad-=0.15f;
运行结果：
(注：本教程转自其他网页，并加以修改，查看原网页请点击这里)