一、基本思路
1.如何检测碰撞
2.贴图的处理,因为位图底色为白色,屏蔽图与之前完全相反,如图所示
因为二进制全0表示黑色,全1表示白色,故首先将屏蔽图与背景图做OR运算,那么背景图会留下白色的部分,然后将前景图再与背景图做AND运算,最后只显示彩图;
3.用vx1、vx2的第一、二部的车速,(x1,y1),(x2,y2)表示两辆车的贴图坐标;
二、效果
三、主要代码如下
// canvasFrame.cpp : implementation file
//
#include "stdafx.h"
#include "canvasr.h"
#include "canvasFrame.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
// canvasFrame
IMPLEMENT_DYNCREATE(canvasFrame, CFrameWnd)//声明canvasFrame类是从CFrameWnd类派生
int vx1=5,vx2=-5,x1=-70,x2=520,y1=165,y2=150;
canvasFrame::canvasFrame()//canvasFrame()是属于canvasFrame类中的一个函数,用于贴图前的初始化
{
Create(NULL,"绘图窗口");//Create是CFrameWnd继承而来的成员函数,用于窗口的创建和设置
CClientDC dc(this);//类CClientDC派生于CDC,在构造时调用了Windows函数GetDC,在析构时调用了ReleaseDC。这意味着和CClientDC对象相关的设备上下文是窗口的客户区
int width = dc.GetDeviceCaps(HORZRES);//this指向被调成员所指的对象
int height = dc.GetDeviceCaps(VERTRES);
GetWindowRect( &rect );
width = ( width - ( rect.right - rect.left ))/2;
height = (height - (rect.bottom - rect.top ))/2;
MoveWindow( width , height , (rect.right - rect.left )/2 , (rect.bottom - rect.top )/1.5 ,true);
GetClientRect(&rect);
mdc = new CDC;
mdc->CreateCompatibleDC(&dc);
car1 = new CBitmap;
car2 = new CBitmap;
bomb = new CBitmap;
car1->m_hObject = (HBITMAP)::LoadImage(NULL,"car1.bmp",IMAGE_BITMAP,196,66,LR_LOADFROMFILE);
car2->m_hObject = (HBITMAP)::LoadImage(NULL,"car2.bmp",IMAGE_BITMAP,140,80,LR_LOADFROMFILE);
bomb->m_hObject = (HBITMAP)::LoadImage(NULL,"bomb.bmp",IMAGE_BITMAP,187,200,LR_LOADFROMFILE);
}
canvasFrame::~canvasFrame()
{
delete mdc;
delete car1;
delete car2;
delete bomb;
}
BEGIN_MESSAGE_MAP(canvasFrame, CFrameWnd)
//{{AFX_MSG_MAP(canvasFrame)
ON_WM_TIMER()
ON_WM_CREATE()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
// canvasFrame message handlers
void canvasFrame::OnTimer(UINT nIDEvent)
{
CFrameWnd::OnTimer(nIDEvent);//开始定时器计时
CClientDC dc(this);
mdc->SelectObject(car1);
dc.BitBlt(x1,y1,196,66,mdc,0,0,SRCCOPY);//贴第一部车
mdc->SelectObject(car2);
dc.BitBlt(x2,y2,140,80,mdc,0,0,SRCCOPY);//贴第二部车
if(x1+196>x2)//发生碰撞
{
mdc->SelectObject(bomb);
dc.BitBlt(x2-100,y2,187,100,mdc,0,100,SRCPAINT);
dc.BitBlt(x2-100,y2,187,100,mdc,0,0,SRCAND);
KillTimer(nIDEvent);//停止计时
}
x1+=vx1;//未碰撞更改车的贴图位置
x2+=vx2;
}
int canvasFrame::OnCreate(LPCREATESTRUCT lpCreateStruct) //初始化定时器
{
if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
return -1;
SetTimer(1,0,NULL);//这里查到不需要填入hwnd了
return 0;
}