【cocos2d-x IOS游戏开发-捕鱼达人17】炮弹攻击判定

尊重开发者的劳动成果，转载的时候请务必注明出处：http://blog.csdn.net/haomengzhu/article/details/17153099

上节回顾

【cocos2d-x IOS游戏开发-捕鱼达人16】炮弹攻击效果2

1、  炮弹攻击判定方式

判定规则
鱼网会有一个自己的包围盒
鱼会有一个自己的包围盒

若两包围盒若相交，表示鱼被捕

包围盒的计算方式
包围盒是一个正方形（避免因为旋转带来的麻烦）
以单位的宽和高的最小值作为边长

 2、 代码实现的关键点

矩形的相交算法
使用内置函数CCRect::intersectsRect或自己封装
RenderObject需要提供包围盒
鱼被攻击后，死亡判定和动画播放

具体实现：

#include "GameObject.h"#include "GameLogic.h"namespace fishingjoy{namespace logic{void CFishObject::updateMove( float dt ){float dx = m_TargetX - m_CurrentX;float dy = m_TargetY - m_CurrentY;float len = sqrt(dx*dx+dy*dy);if(len<0.001){if(m_bMoveToAndStop){m_eGameObjectState = EGOS_IDLE;m_bMoveToAndStop = false;return;}if(m_bMoveToAndDestroy){m_eGameObjectState = EGOS_IDLE;m_bNeedDestroyed = true;m_bMoveToAndDestroy = false;return;}randomTarget();return;}dx/=len;dy/=len;float newX = m_CurrentX + dx*dt*m_pFishData->NormalSpeed;float newY = m_CurrentY + dy*dt*m_pFishData->NormalSpeed;float dx2 = newX - m_CurrentX;float dy2 = newY - m_CurrentY;float dx3 = m_TargetX - m_CurrentX;float dy3 = m_TargetY - m_CurrentY;if(dx2*dx2+dy2*dy2 >= dx3*dx3+dy3*dy3){setPosition(m_TargetX,m_TargetY);if(m_bMoveToAndStop){m_eGameObjectState = EGOS_IDLE;m_bMoveToAndStop = false;return;}if(m_bMoveToAndDestroy){m_eGameObjectState = EGOS_IDLE;m_bNeedDestroyed = true;m_bMoveToAndDestroy = false;return;}randomTarget();}else{setPosition(newX,newY);}}void CFishObject::onHit( int atk ){if(m_iHp <= atk){m_eGameObjectState = EGOS_DIE;m_pSceneObject->setAnimation("die");m_Time = 0;((CGameLogic*)m_pGameLogic)->addMark(m_pFishData->Mark);}else{m_iHp -= atk;}}//判断是否碰撞bool CBulletObject::isRectCollision (CCRect rect1, CCRect rect2){float x1 = rect1.origin.x;float y1 = rect1.origin.y;float w1 = rect1.size.width;float h1 = rect1.size.height;float x2 = rect2.origin.x;float y2 = rect2.origin.y;float w2 = rect2.size.width;float h2 = rect2.size.height;if (x1+w1*0.5<x2-w2*0.5)  return false;else if (x1-w1*0.5>x2+w2*0.5)return false;else if (y1+h1*0.5<y2-h2*0.5)return false;else if (y1-h1*0.5>y2+h2*0.5)return false;return true;}void CBulletObject::updateNormal( float dt ){float angle = (90-m_Dir)/180*3.1416926;float s = sin(angle);float c = cos(angle);float dtx = m_Speed*c*dt;float dty = m_Speed*s*dt;m_CurrentX += dtx;m_CurrentY += dty;m_pSceneObject->setPosition(m_CurrentX,m_CurrentY);dtx = m_CurrentX - m_OrgX;dty = m_CurrentY - m_OrgY;bool over = false;CGameLogic* pLogic = (CGameLogic*)m_pGameLogic;std::vector<CFishObject*>& rFishs = pLogic->getFishs();std::vector<CFishObject*>::iterator it = rFishs.begin();std::vector<CFishObject*>::iterator end = rFishs.end();for(;it!=end;++it){CFishObject* pFish = *it;if(pFish->isDead()){continue;}float fishW = pFish->getSceneObj()->getWidth();float fishH = pFish->getSceneObj()->getHeight();float fShort = fishW < fishH? fishW:fishH;CCRect rectFish = CCRectMake(pFish->getPosX()+fShort/2,pFish->getPosY()+fShort/2,fShort,fShort);float bulletW = m_pSceneObject->getWidth();float bulletH = m_pSceneObject->getHeight();fShort = bulletW < bulletH? bulletW:bulletH;CCRect rectBullet = CCRectMake(m_CurrentX+fShort/2,m_CurrentY+fShort/2,fShort,fShort);//在cocos2d-x 的2.0.4 版本中,CCRectEqualToRect 、CCRectContainsPoint、CCRectIntersectsRect已不再推荐使用,//取而代之的是 equals、containsPoint、intersectsRect。//bool intersect = CCRect::CCRectIntersectsRect(rectBullet,rectFish);//新版本可以使用精灵调用intersectsRect//if (sp1->boundingBox().intersectsRect(sp2->boundingBox()))//自己封装bool intersect = this->isRectCollision(rectBullet,rectFish);if(intersect){over = true;pFish->onHit(m_iAtk);printf("hit!!!!!!\n");}}if((dtx*dtx+dty*dty > m_Distance*m_Distance)|| over){m_Time = 0;m_eButtletObjectState = EBOS_EXPLODE;m_pSceneObject->setAnimation("net");}}void CBulletObject::update( float dt ){m_Time+=dt;switch(m_eButtletObjectState){case EBOS_NORMAL:updateNormal(dt);break;case EBOS_EXPLODE:if(m_Time > EXPLODE_TIME){m_bNeedDestroyed = true;}break;}}}}

可以看到效果图：

本节源代码与工程文件：【资源引用页】