android 2d游戏的遮挡和碰撞实现

package org.opengl.game; import java.util.Arrays; import java.util.Comparator; import javax.microedition.khronos.opengles.GL10; /** * 图层管理器 * 可以动态设置图片,来显示遮挡效果 * 可以动态调用procShelter(Layer the,Layer other)方法实现遮挡 * 可以动态调用collidesImpl(Layer the,Layer other)方法来实现碰撞检测 * @author 张世洋 * @date 2011-10-14 * @QQ 381715271 */ public class LayerManager implements Comparator<Layer>{ private Layer[] layers=new Layer[4]; private int nlayers; public LayerManager(){ } public void draw(GL10 gl){ for (int i =0;i<nlayers;i++){ Layer layer=layers[i]; layer.draw(gl); } } /** * Appends a Layer to this LayerManager. The Layer is appended to the * list of existing Layers such that it has the highest index (i.e. it * is furthest away from the user). The Layer is first removed * from this LayerManager if it has already been added. * * @see #insert(Layer, int) * @see #remove(Layer) * @param l the <code>Layer</code> to be added * @throws NullPointerException if the <code>Layer</code> is * <code>null</code> */ public void append(Layer layer) { // remove the Layer if it is already present // will throw NullPointerException if the Layer is null removeImpl(layer); addImpl(layer, nlayers); } /** * Inserts a new Layer in this LayerManager at the specified index. * The Layer is first removed from this LayerManager if it has already * been added. * @see #append(Layer) * @see #remove(Layer) * @param l the <code>Layer</code> to be inserted * @param index the index at which the new <code>Layer</code> is * to be inserted * @throws NullPointerException if the <code>Layer</code> is * <code>null</code> * @throws IndexOutOfBoundsException if the index is less than * <code>0</code> or * greater than the number of Layers already added to the this * <code>LayerManager</code> */ public void insert(Layer layer, int index) { /* Check for correct arguments: index in bounds */ if ((index < 0) || (index > nlayers)) { throw new IndexOutOfBoundsException(); } // if the Layer is already present // remove it // will throw NullPointerException if the Layer is null removeImpl(layer); // insert it at the specified index addImpl(layer, index); } /** * Removes the specified Layer from this LayerManager. This method does * nothing if the specified Layer is not added to the this LayerManager. * @see #append(Layer) * @see #insert(Layer, int) * @param l the <code>Layer</code> to be removed * @throws NullPointerException if the specified <code>Layer</code> is * <code>null</code> */ public void remove(Layer l) { removeImpl(l); } /** * add or insert a layer * @param layer The Layer to be inserted * @param index the position at which to insert the layer */ private void addImpl(Layer layer, int index) { // Add component to list; // allocate new array if necessary. if (nlayers == layers.length) { Layer newlayers[] = new Layer[nlayers + 4]; System.arraycopy(layers, 0, newlayers, 0, nlayers); System.arraycopy(layers, index, newlayers, index + 1, nlayers - index); layers = newlayers; } else { System.arraycopy(layers, index, layers, index + 1, nlayers - index); } layers[index] = layer; nlayers++; } /** * Removes the specified Layer from this LayerManager. * @param l The Layer to be removed * @throws NullPointerException if the specified Layer is null **/ private void removeImpl(Layer layer) { if (layer== null) { throw new NullPointerException(); } /** * Search backwards, expect that more recent additions * are more likely to be removed. */ for (int i = nlayers; --i >= 0; ) { if (layers[i] == layer) { remove(i); } } } /** * remove a layer at the specified index. * @param index the position at which to insert the layer, */ private void remove(int index) { System.arraycopy(layers, index + 1, layers, index, nlayers - index - 1); layers[--nlayers] = null; } public void removeAll(){ for(int i=nlayers-1;i>0;i--){ remove(i); } } /* * 对图层数组进行排序，来实现遮挡效果 */ private void sortLayer(){ Arrays.sort(layers, this); } /* * 处理遮挡 * 通过比较图层深度和当前的模型y坐标，动态交互图层来实现 */ public void procShelter(Layer the,Layer other){ // float y1=the.getY(); // float y2=other.getY(); // int id1=the.getLayerNum(); // int id2=other.getLayerNum(); if(this.collidesImpl(the, other)){//发送了碰撞,进行排序 this.sortLayer(); // float x1=the.getX(); // float x2=other.getX(); // if((x1<x2)&&(id1<id2)){ // the.setLayerNum(id2); // other.setLayerNum(id1); // this.insert(the,id2); // this.insert(other, id1); // return ; // }else if((x1>x2)&&(id1>id2)){ // the.setLayerNum(id2); // other.setLayerNum(id1); // this.insert(the,id2); // this.insert(other, id1); // return; // } } // if((y1<y2)&&(id1<id2)){ // the.setLayerNum(id2); // other.setLayerNum(id1); // this.insert(the,id2); // this.insert(other, id1); // return ; // } // if((y1>y2)&&(id2>id2)){ // the.setLayerNum(id2); // other.setLayerNum(id1); // this.insert(the, id2); // this.insert(other, id1); // return; // } } /* * 碰撞检测 * param other 要检测的对象 * return 发送碰撞是返回true */ public boolean collidesImpl(Layer the,Layer other){ float otherX=other.getX(); float otherY=other.getY(); float theX=the.getX(); float theY=the.getY(); float otherW=other.getWidth(); float otherH=other.getHeight(); float theW=the.getWidth(); float theH=the.getHeight(); if(theX<otherX+otherW&&theX+theW>otherX&& theY<otherY+otherH&&theY+theH>otherY){ return true; } return false; } /* * 碰撞检测 * param other 要检测的对象 * return 发送碰撞是返回true */ public boolean collidesWith(Layer the,Layer other){ float otherX=other.getCollidesX(); float otherY=other.getCollidesY(); float theX=the.getCollidesX(); float theY=the.getCollidesY(); float otherW=other.getCollidesW(); float otherH=other.getCollidesH(); float theW=the.getCollidesW(); float theH=the.getCollidesH(); if(theX<otherX+otherW&&theX+theW>otherX&& theY<otherY+otherH&&theY+theH>otherY){ return true; } return false; } /* * Comparator接口的比较方法 * 对两个图层实例进行比较 * 比较的具体实现是根据Y坐标 * 实现这个接口是为了实现遮挡效果 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object) */ @Override public int compare(Layer lhs, Layer rhs) { float l=lhs.getY(); float r=rhs.getY(); if(l<r){ return 1; }else if(l>r){ return -1; }else{ return 0; } } }