应用源码之(Boxd物理世界.zip

package com.hb; import org.jbox2d.collision.AABB; import org.jbox2d.common.Vec2; import org.jbox2d.dynamics.World; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.SurfaceHolder.Callback; public class MySurfaceView extends SurfaceView implements Callback, Runnable { private Thread th; private SurfaceHolder sfh; private Canvas canvas; private Paint paint; private boolean flag; // ----添加一个物理世界---->> final float RATE = 30;// 屏幕到现实世界的比例 30px：1m; World world;// 声明一个物理世界对象 AABB aabb;// 声明一个物理世界的范围对象 Vec2 gravity;// 声明一个重力向量对象 float timeStep = 1f / 60f;// 物理世界模拟的的频率 int iterations = 10;// 迭代值，迭代越大模拟越精确，但性能越低 public MySurfaceView(Context context) { super(context); this.setKeepScreenOn(true); sfh = this.getHolder(); sfh.addCallback(this); paint = new Paint(); paint.setAntiAlias(true); setFocusable(true); // --添加一个物理世界--->> aabb = new AABB();// 实例化物理世界的范围对象 gravity = new Vec2(0, 10);// 实例化物理世界重力向量对象 aabb.lowerBound.set(-100, -100);// 设置物理世界范围的左上角坐标 aabb.upperBound.set(100, 100);// 设置物理世界范围的右下角坐标 world = new World(aabb, gravity, true);// 实例化物理世界对象 } public void surfaceCreated(SurfaceHolder holder) { flag = true; th = new Thread(this); th.start(); } public void myDraw() { try { canvas = sfh.lockCanvas(); if (canvas != null) { canvas.drawColor(Color.WHITE); } } catch (Exception e) { Log.e("Himi", "myDraw is Error!"); } finally { if (canvas != null) sfh.unlockCanvasAndPost(canvas); } } public void Logic() { // --开始模拟物理世界--->> world.step(timeStep, iterations);// 物理世界进行模拟 } public void run() { while (flag) { myDraw(); Logic(); try { Thread.sleep((long) timeStep * 1000); } catch (Exception ex) { Log.e("Himi", "Thread is Error!"); } } } public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } public void surfaceDestroyed(SurfaceHolder holder) { flag = false; } }