OpenGL ES 画三角

OpenGL ES 画三角形

上三角形：

public class GL2 extends Activity {

	private GLSurfaceView mGLSurfaceView;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		mGLSurfaceView = new GLSurfaceView(this);
		mGLSurfaceView.setRenderer(new Two());
		setContentView(mGLSurfaceView);
	}

	@Override
	protected void onResume() {
		super.onResume();
		mGLSurfaceView.onResume();
	}

	@Override
	protected void onPause() {
		super.onPause();
		mGLSurfaceView.onPause();
	}
}

class Two implements Renderer {

	private Triangle triangle;

	public Two() {
		triangle = new Triangle();
	}

	@Override
	public void onDrawFrame(GL10 gl) {
		gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
		gl.glLoadIdentity();

		gl.glTranslatef(0.0f, 0.0f, -6.0f);
		triangle.draw(gl);
	}

	@Override
	public void onSurfaceCreated(GL10 gl, EGLConfig config) {
		gl.glShadeModel(GL10.GL_SMOOTH);
		gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
		gl.glClearDepthf(1.0f);
		gl.glEnable(GL10.GL_DEPTH_TEST);
		gl.glDepthFunc(GL10.GL_LEQUAL);
		
		gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
	}

	@Override
	public void onSurfaceChanged(GL10 gl, int width, int height) {
		if (height == 0) {
			height = 1;
		}

		gl.glViewport(0, 0, width, height);
		gl.glMatrixMode(GL10.GL_PROJECTION);
		gl.glLoadIdentity();

		GLU.gluPerspective(gl, 45.0f, (float) width / (float) height, 0.1f,
				100.0f);

		gl.glMatrixMode(GL10.GL_MODELVIEW);
		gl.glLoadIdentity();
	}
}

class Triangle {
	private FloatBuffer vertexBuffer;

	private float vertices[] = { 0.0f, 1.0f, 0.0f, -1.0f, -1.0f, 0.0f, 1.0f,
			-1.0f, 0.0f };

	public Triangle() {
		ByteBuffer byteBuf = ByteBuffer.allocateDirect(vertices.length * 4);
		byteBuf.order(ByteOrder.nativeOrder());
		vertexBuffer = byteBuf.asFloatBuffer();
		vertexBuffer.put(vertices);
		vertexBuffer.position(0);
	}

	public void draw(GL10 gl) {
		gl.glFrontFace(GL10.GL_CW);
		gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
		gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
		gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
		gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
	}

}

  三角形与正方形差不多，注释参考上一篇：http://yuanyao.iteye.com/blog/782474