物体的阻尼运动

最新推荐文章于 2024-05-25 16:16:17 发布

原创最新推荐文章于 2024-05-25 16:16:17 发布 · 1.3k 阅读

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#include <Windows.h>
#include <iostream>

const int X=200,Y=50; //程序窗口左上角相对于屏幕的坐标
const int WIDTH=640,HEIGHT=480; // //程序窗口的宽与高

DWORD tPre,tNow; //tPre记录上一次绘图的时间，tNow记录此次准备绘图的时间
int x=0,y=0,vx=3,vy=0,gy=1; //x、y表示物体的初始位置

HDC hdc,mdc,bufdc;
HBITMAP bg,dra;
RECT rect;

void MyPaint(HDC);
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow)
{
const std::string szTitle="阻尼运动";

WNDCLASS winclass={CS_HREDRAW|CS_VREDRAW,WndProc,0,0,hInstance,LoadIcon(NULL,IDI_APPLICATION),
LoadCursor(NULL,IDC_ARROW),(HBRUSH)GetStockObject(WHITE_BRUSH),NULL,szTitle.c_str()};

if(!RegisterClass(&winclass))
return false;

HWND hWnd=CreateWindow(szTitle.c_str(),szTitle.c_str(),WS_OVERLAPPEDWINDOW,X,Y,WIDTH,HEIGHT,
NULL,NULL,winclass.hInstance,NULL);

if(0==hWnd)
return 0;

ShowWindow(hWnd,SW_SHOWDEFAULT);
UpdateWindow(hWnd);

MSG msg;
ZeroMemory(&msg,sizeof(MSG));

while(msg.message!=WM_QUIT)
{
  if(PeekMessage(&msg,NULL,0,0,PM_REMOVE))
  {
   TranslateMessage(&msg);
   DispatchMessage(&msg);
  }
  else
  {
   tNow=GetTickCount();
   while(tNow-tPre>=30)
    MyPaint(hdc);
  }
}
return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT message,WPARAM wParam,LPARAM lParam)
{
HBITMAP bmp;

switch(message)
{
case WM_CREATE:
  {
   hdc=GetDC(hWnd);
   mdc=CreateCompatibleDC(hdc);
   bufdc=CreateCompatibleDC(hdc);
   bmp=CreateCompatibleBitmap(hdc,WIDTH,HEIGHT);
   SelectObject(mdc,bmp);

   //加载物体位图
   bg=(HBITMAP)LoadImage(NULL,"bg.bmp",IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
   dra=(HBITMAP)LoadImage(NULL,"dra.bmp",IMAGE_BITMAP,0,0,LR_LOADFROMFILE);

   GetClientRect(hWnd,&rect);  //取得内部窗口区域大小
  }
  break;

case WM_KEYDOWN:
  {
   if(wParam==VK_ESCAPE)
    DestroyWindow(hWnd);
  }
  break;

case WM_DESTROY:
  {
   DeleteDC(bufdc);
   DeleteDC(mdc);
   DeleteObject(bg);
   DeleteObject(dra);
   ReleaseDC(hWnd,hdc);
   PostQuitMessage(0);
  }
  break;

default:
return DefWindowProc(hWnd,message,wParam,lParam);
}
return 0;
}

void MyPaint(HDC hdc)
{
//贴背景图
SelectObject(bufdc,bg);
BitBlt(mdc,0,0,WIDTH,HEIGHT,bufdc,0,0,SRCCOPY);

//贴物体图
SelectObject(bufdc,dra);
BitBlt(mdc,x,y,50,50,bufdc,50,0,SRCAND);
BitBlt(mdc,x,y,50,50,bufdc,0,0,SRCPAINT);
BitBlt(hdc,0,0,WIDTH,HEIGHT,mdc,0,0,SRCCOPY);

x+=vx;  //计算x轴方向物体坐标
vy+=gy;  //计算y轴方向速度分量
y+=vy;  //计算y轴方向贴图坐标

if(y>=rect.bottom-50)
{
  y=rect.bottom-50;
  vx-=1;
  if(vx<0)
   vx=0;

  vy-=4;
  if(vy<0)
   vy=0;
  vy=-vy;
}

tPre=GetTickCount();
}