//目前设置了360个随机方向,可以更改M置产生更多随机方向
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
#include<time.h>

#define SCREEN_X  640
#define SCREEN_Y  480//屏幕大小
#define M         360   //1<=方向数目<=360
#define PI 3.141592653589793
#define N          10
#define V          10  //控制运动速度
int               R=10;//圆心坐标和半径
struct yuanxin
{
  int A;
  int B;
};

struct yuanxin *move(struct yuanxin *p,int R,int n);//让球运动的函数

int main(void)
{
    //绘图窗口相关设置
    initgraph(SCREEN_X , SCREEN_Y);
    setbkcolor(WHITE);
    cleardevice();
    srand((unsigned)time(NULL));//设置随机数种子
   
    int n;//控制方向数目
    struct yuanxin O,*p;
    p=&O;//指向圆心的指针
   
    p->A = rand()%241+200;
    p->B = rand()%81+200;
    n = rand()%9;            //产生随机数
   
    while(!kbhit())
    {
        //判断遇到了哪种边界
        if( SCREEN_X -(p->A)<=R)        n=rand()%(M/2+1)+(M/2);
        else if((p->A)<=R)        n=rand()%(M/2+1);
        else if(SCREEN_Y -(p->B)<=R)    n=rand()%(M/2+1)%+(3*M/4);
        else if((p->B)<=R)        n=rand()%(M/2+1)+(M/4);   
        else                n=rand()%(M+1);
        p = move(p,R,n);//遇到边界后任意弹回
    }

    getch();
    closegraph();
    return 0;
}


struct yuanxin *move(struct yuanxin *p,int R,int n)
{   
    struct yuanxin *p2;
    p2=p;

    do
    {
        setfillcolor(LIGHTGREEN);
        fillcircle(p2->A,p2->B,R);
        Sleep(V);
        setfillcolor(GREEN);
        fillcircle(p2->A,p2->B,R);
        //Sleep(V);
        p2->A += N*sin(n* 2*PI/M),p2->B -= N*cos(n* 2*PI/M);
    }
    while( !(( SCREEN_X -(p2->A)<=R) || ((p2->A)<=R) || (SCREEN_Y -(p2->B)<=R) || ((p2->B)<=R)) );//没有到达边界

    return(p2);//到达边界后返回主函数，带回指向圆心的指针
   
}

[ 本帖最后由 haiboself 于 2013-11-22 14:23 编辑 ]

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