试一下 moving ball

\*******'w'加速,'s'减速,'a','d'转向************

#include <bios.h>

#include <math.h>

#include <graphics.h>

#include <stdio.h>

#include <time.h>

#include <dos.h>

#define PI 3.14159265

#define r 15

#define c(c) setfillstyle(1,c)

main()

{int x=320,y=240,x0=320,y0=240;float v=0,t=0,a=0;

char k='0';

int gdriver=DETECT,gmode;

initgraph(&gdriver,&gmode,"c:\\tc2\\bgi");

setcolor(15);

setwritemode(XOR_PUT);

while(k!='q')

{while(bioskey(1)==0)

{printf("t=%f,v=%f,a=%f(%d,%d)\r",t,v,a,x,y);

if(x<=0x>=639)a=PI-a;if(y<=0y>=479)a=-a;

x=v*cos(a)*t+x;y=v*sin(a)*t+y;

line(x0,y0,x,y);

circle(x,y,5);

delay(5000);

circle(x,y,5);

x0=x;y0=y;

t+=0.01;

}

k=bioskey(0);

switch(k)

{case 'a': a-=0.1;break;

case 'd': a+=0.1;break;

case 's': v-=0.1;break;

case 'w': v+=0.1;break;

}

}

}