应用源码之(AABB获取Body).zip

package com.agb; import org.jbox2d.collision.AABB; import org.jbox2d.collision.CircleDef; import org.jbox2d.collision.Shape; import org.jbox2d.common.Vec2; import org.jbox2d.dynamics.Body; import org.jbox2d.dynamics.BodyDef; import org.jbox2d.dynamics.World; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Paint.Style; import android.util.Log; import android.view.MotionEvent; 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 // ---记录AABB中body的数量 private int bodySize; private float touchX, touchY; private int range = 10; public MySurfaceView(Context context) { super(context); this.setKeepScreenOn(true); sfh = this.getHolder(); sfh.addCallback(this); paint = new Paint(); paint.setAntiAlias(true); paint.setStyle(Style.STROKE); this.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 // ----在物理世界中添加多个圆形Body for (int i = 0; i < 10; i++) { createCircle(130, 10 + i * 17, 10, false); } for (int i = 0; i < 5; i++) { createCircle(112 + i * 20, 300, 10, true); } } public void surfaceCreated(SurfaceHolder holder) { flag = true; th = new Thread(this); th.start(); } /** * * @param x * 获取body的范围中心点x坐标 * @param y * 获取body的范围中心点y坐标 * @param range * 以xy位置为中心点的的范围值[x-range,y-range][x+range,y+range] * @param maxCount * 限制最大返回Body的个数 * @return */ public Shape[] getBodies(float x, float y, float range, int maxCount) { AABB aabbBody = new AABB(); aabbBody.lowerBound.set((x - range) / RATE, (y - range) / RATE); aabbBody.upperBound.set((x + range) / RATE, (y + range) / RATE); Shape[] shapes = world.query(aabbBody, maxCount); // 遍历此aabb范围中的body，筛选操作 for (int i = 0; i < shapes.length; i++) { if (shapes[i].getBody().isStatic()) { // ...判定物体是否为静态 } if (shapes[i].getBody().isSleeping()) { // ...判定物体是否进入休眠 } } return shapes; } @Override public boolean onTouchEvent(MotionEvent event) { Shape[] sp = getBodies(touchX = event.getX(), touchY = event.getY(), range, 10); bodySize = sp.length; return true; } public Body createCircle(float x, float y, float r, boolean isStatic) { CircleDef cd = new CircleDef(); if (isStatic) { cd.density = 0; } else { cd.density = 1; } cd.friction = 0.8f; cd.restitution = 0.3f; cd.radius = r / RATE; BodyDef bd = new BodyDef(); bd.position.set((x + r) / RATE, (y + r) / RATE); Body body = world.createBody(bd); body.m_userData = new MyCircle(x, y, r); body.createShape(cd); body.setMassFromShapes(); return body; } public void myDraw() { try { canvas = sfh.lockCanvas(); if (canvas != null) { canvas.drawColor(Color.WHITE); paint.setColor(Color.BLACK); Body body = world.getBodyList(); for (int i = 1; i < world.getBodyCount(); i++) { ((MyCircle) body.m_userData).draw(canvas, paint); body = body.m_next; } canvas.drawText("与指定AABB范围相交了" + bodySize + "个Body！", 20, 50, paint); Paint paintAABB = new Paint(); paintAABB.setStyle(Style.STROKE); paintAABB.setColor(0xffff0000); canvas.drawCircle(touchX, touchY, range, paintAABB); } } 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 // 取出body链表表头 Body body = world.getBodyList(); for (int i = 1; i < world.getBodyCount(); i++) { // 设置MyCircle的X，Y坐标 MyCircle mc = (MyCircle) body.m_userData; mc.setX(body.getPosition().x * RATE - mc.r); mc.setY(body.getPosition().y * RATE - mc.r); // 将链表指针指向下一个body元素 body = body.m_next; } } 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; } }