glworld.java

android 例子中的确良ApiDemos。很有代表意义

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.graphics.kube;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;
import java.nio.ShortBuffer;
import java.util.Iterator;
import java.util.ArrayList;

import javax.microedition.khronos.opengles.GL10;

public class GLWorld {

	public void addShape(GLShape shape) {
		mShapeList.add(shape);
		mIndexCount += shape.getIndexCount();
	}
	
	public void generate() {		
	    ByteBuffer bb = ByteBuffer.allocateDirect(mVertexList.size()*4*4);
	    bb.order(ByteOrder.nativeOrder());
		mColorBuffer = bb.asIntBuffer();

	    bb = ByteBuffer.allocateDirect(mVertexList.size()*4*3);
	    bb.order(ByteOrder.nativeOrder());
	    mVertexBuffer = bb.asIntBuffer();

	    bb = ByteBuffer.allocateDirect(mIndexCount*2);
	    bb.order(ByteOrder.nativeOrder());
	    mIndexBuffer = bb.asShortBuffer();

		Iterator<GLVertex> iter2 = mVertexList.iterator();
		while (iter2.hasNext()) {
			GLVertex vertex = iter2.next();
			vertex.put(mVertexBuffer, mColorBuffer);
		}

		Iterator<GLShape> iter3 = mShapeList.iterator();
		while (iter3.hasNext()) {
			GLShape shape = iter3.next();
			shape.putIndices(mIndexBuffer);
		}
	}
	
	public GLVertex addVertex(float x, float y, float z) {
		GLVertex vertex = new GLVertex(x, y, z, mVertexList.size());
		mVertexList.add(vertex);
		return vertex;
	}
	
	public void transformVertex(GLVertex vertex, M4 transform) {
		vertex.update(mVertexBuffer, transform);
	}

	int count = 0;
    public void draw(GL10 gl)
    {
		mColorBuffer.position(0);
		mVertexBuffer.position(0);
		mIndexBuffer.position(0);

		gl.glFrontFace(GL10.GL_CW);
        gl.glShadeModel(GL10.GL_FLAT);
        gl.glVertexPointer(3, GL10.GL_FIXED, 0, mVertexBuffer);
        gl.glColorPointer(4, GL10.GL_FIXED, 0, mColorBuffer);
        gl.glDrawElements(GL10.GL_TRIANGLES, mIndexCount, GL10.GL_UNSIGNED_SHORT, mIndexBuffer);
        count++;
    }
   
    static public float toFloat(int x) {
    	return x/65536.0f;
    }

	private ArrayList<GLShape>	mShapeList = new ArrayList<GLShape>();	
	private ArrayList<GLVertex>	mVertexList = new ArrayList<GLVertex>();
	
	private int mIndexCount = 0;

    private IntBuffer   mVertexBuffer;
    private IntBuffer   mColorBuffer;
    private ShortBuffer mIndexBuffer;
}