运用GLU.gluOrtho2D画的一个可以旋转的正方形

使用GLU.gluOrtho2D画的一个可以旋转的正方形

package com.zlb.DemoRect2;

import static android.opengl.GLES10.GL_CCW;
import static android.opengl.GLES10.GL_FLOAT;
import static android.opengl.GLES10.GL_TEXTURE_2D;
import static android.opengl.GLES10.GL_TRIANGLE_STRIP;
import static android.opengl.GLES10.GL_UNSIGNED_SHORT;
import static android.opengl.GLES10.glDrawElements;
import static android.opengl.GLES10.glEnable;
import static android.opengl.GLES10.glFrontFace;
import static android.opengl.GLES10.glTexCoordPointer;
import static android.opengl.GLES10.glVertexPointer;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.opengles.GL11;

import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.opengl.GLU;
import android.opengl.GLSurfaceView.Renderer;
import android.os.Bundle;
import android.os.SystemClock;
import android.util.Log;

public class DemoRect2Activity extends Activity {
	GLSurfaceView mGLSurfaceView;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		mGLSurfaceView = new GLSurfaceView(this);
		mGLSurfaceView.setRenderer(new RectRenderer());
		setContentView(mGLSurfaceView);
	}

	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
		mGLSurfaceView.onPause();
	}

	@Override
	protected void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
		mGLSurfaceView.onResume();
	}
}

class RectRenderer implements Renderer {

	private Triangle mTriangle;
	private long mLastTime;

	public RectRenderer() {
		mTriangle = new Triangle();
	}

	public void onDrawFrame(GL10 gl) {
		gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
		gl.glMatrixMode(GL10.GL_MODELVIEW);
		gl.glLoadIdentity();
		
//		gl.glTranslatef(0.0f, 0.0f, -8.0f);
		GLU.gluLookAt(gl, 0f, 0f, 1f, 0f, 0f, 0f, 0f, 1f, 0f);

		long time = SystemClock.uptimeMillis() % 4000L;
		float angle = 0.090f * ((int) time);
		Log.d("zhang", "///////////////////////////////////////=======angle = "+angle);
		gl.glRotatef(angle, 0, 1f, 0);
		mTriangle.draw(gl);
	}

	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();
		Log
				.d("zhanglibin",
						">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
//		GLU.gluPerspective(gl, 45.0f, (float) width / (float) height, 0.1f,
//				100.0f);
//		gl.glFrustumf(-(float)width/height,(float)width/height, -1f, 1f, 2f, 100f);
//		 GLU.gluOrtho2D(gl, 0f, (float)width, 0f, (float)height);
//		 gl.glOrthof(-(float)width/2, (float)width/2, -(float)height/2,
//				 (float)height/2, -1, 100f);
		 GLU.gluOrtho2D(gl, -(float)width/2, (float)width/2, -(float)height/2,
		 (float)height/2);

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

	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.glDepthFunc(GL10.GL_LEQUAL);
		gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
	}
}

class Triangle {
	public Triangle() {

		ByteBuffer vbb = ByteBuffer.allocateDirect(VERTS * 3 * 4);
		vbb.order(ByteOrder.nativeOrder());
		mFVertexBuffer = vbb.asFloatBuffer();

		ByteBuffer tbb = ByteBuffer.allocateDirect(VERTS * 2 * 4);
		tbb.order(ByteOrder.nativeOrder());
		mTexBuffer = tbb.asFloatBuffer();

		ByteBuffer ibb = ByteBuffer.allocateDirect(VERTS * 2);
		ibb.order(ByteOrder.nativeOrder());
		mIndexBuffer = ibb.asShortBuffer();

//		float[] coords = {
//		// X, Y, Z
//				-0.5f, -0.25f, 0, 0.5f, -0.25f, 0, 0.0f, 0.559016994f, 0 };
//		float[] coords = {
//		// X, Y, Z
//				0, 0, -20, 1, 0, -20, 0.5f, 1, -20 };
		float[] coords = {
				// X, Y, Z
						 100f, -100f, 0f, -100f, -100f, 0f, 100f, 100f, 0f, -100f, 100f, 0f};
		

		for (int i = 0; i < VERTS; i++) {
			for (int j = 0; j < 3; j++) {
				mFVertexBuffer.put(coords[i * 3 + j] * 2.0f);
			}
		}

		for (int i = 0; i < VERTS; i++) {
			for (int j = 0; j < 2; j++) {
				mTexBuffer.put(coords[i * 3 + j] * 2.0f + 0.5f);
			}
		}

		for (int i = 0; i < VERTS; i++) {
			mIndexBuffer.put((short) i);
		}

		mFVertexBuffer.position(0);
		mTexBuffer.position(0);
		mIndexBuffer.position(0);
	}

	public float getWidth() {
		return 0f;
	}

	public void draw(GL10 gl) {
		glFrontFace(GL_CCW);
		gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
		glVertexPointer(3, GL_FLOAT, 0, mFVertexBuffer);
		glEnable(GL_TEXTURE_2D);
		glDrawElements(GL_TRIANGLE_STRIP, VERTS, GL_UNSIGNED_SHORT,
				mIndexBuffer);
	}

	private final static int VERTS = 4;

	private FloatBuffer mFVertexBuffer;
	private FloatBuffer mTexBuffer;
	private ShortBuffer mIndexBuffer;
}

旋转效果不咋滴，和GLU.gluOrtho2D这个方法有关，因为这个方法是正投影，如果把这个方法替换为GLU.gluPerspective或者gl.glFrustumf则效果正常。