sprite.cpp

symbian os c++ 碰撞小球 代码

/*
 * Sprite.cpp
 *
 *  Created on: 2009-3-3
 *      Author: pengxingfu
 */

#include "Sprite.h"

CSprite * CSprite::NewL(TInt aXVelocity,TInt aYVelocity, const TPoint& aInitialPosition)
	
{
 CSprite* self = NewLC(aXVelocity,aYVelocity,aInitialPosition);
 CleanupStack::Pop(self);
 return self;
 }

 
CSprite * CSprite::NewLC(TInt aXVelocity,TInt aYVelocity, const TPoint& aInitialPosition)
{
 CSprite* self = new (ELeave) CSprite(aXVelocity,aYVelocity,aInitialPosition);
 CleanupStack::PushL(self);
 self->ConstructL();
 return self;
 }


CSprite::CSprite(TInt aXVelocity,TInt aYVelocity, const TPoint& aInitialPosition)
: iPosition(aInitialPosition),
 iXVelocity(aXVelocity),
 iYVelocity(aYVelocity)
 {
    // No implementation required
 }


CSprite::~CSprite()
 {
    // No implementation required
 }


void CSprite::ConstructL()
 {
    // No implementation required
 }


TPoint CSprite::Position() const
 {
 return iPosition;
 }


void CSprite::Move(const TSize& aSize, const TRect& aBounds)
 {
  //okToMove 判断是否将当前的iPosition置为移动一个速度单位（x，y轴均改变）后的座标
 TBool okToMove = ETrue;
 
 // Calculate the new sprite position
 //算出新的左上角的位置
 TPoint newPostion = iPosition + TPoint(iXVelocity,iYVelocity);
 
 // Check that the new sprite X position is not out of bounds
 TInt width = aSize.iWidth;
 TInt leftX = newPostion.iX;
 TInt rightX = newPostion.iX + width;
 //如果图形的最左边X座标小于 Rect（）的最左端，跑出手机屏幕的左边去了
 //或跑出手机屏幕的右边去了，则将x轴速度反向
 if ((rightX > aBounds.iBr.iX) || (leftX < aBounds.iTl.iX))
  {
  // If it is, "bounce" the sprite off the edge of the boundary
  iXVelocity = -iXVelocity;
  // and don't let it move this tick
  okToMove = EFalse;
  }

 // Check that the new sprite Y position is not out of bounds
 TInt height = aSize.iHeight;
 TInt topY = newPostion.iY;
 TInt bottomY = newPostion.iY + height;
 if ((bottomY > aBounds.iBr.iY) || (topY < aBounds.iTl.iY))
  {
  // If it is, "bounce" the sprite off the edge of the boundary
  iYVelocity = -iYVelocity;
  // and don't let it move this tick
  okToMove = EFalse;
  }

 // If the sprite can move this tick
  //如果经过比较后没有跑到屏幕外面去，预先的移动就是有效的，只需将球的位置改变成移动后的值即可
 if (okToMove)
  {
  // Move it
  iPosition = newPostion;
  }
 }