一个方程实现液体下流效果

#include<stdio.h>
#include<math.h>
#include<graphics.h>
#define PI 3.14
int main()
{
    float i ,j ,x ,y;
    int MAXX2 ,MAXY2;
    int gd = DETECT,gm = 0;

    initgraph(&gd,&gm,"");

    MAXX2 = getmaxx()/2;
    MAXY2 = getmaxy()/2;

    setcolor(15);
    setfillstyle(1 ,2);

    for(j = 0;j < MAXY2*2;j+=40)
    {
        rectangle(1 ,j ,i+39 ,j+21);
        for(i = 0;i < MAXX2*2;i+=40)
        {
            rectangle(i ,j+1 ,i+39 ,j+20);
            floodfill(i+3 ,j+3 ,getcolor());
            rectangle(i+20 ,j+21 ,i+59 ,j+40);
            floodfill(i+23 ,j+23 ,getcolor());
        }
        rectangle(21 ,j+21 ,i+59 ,j+41);
        floodfill(3 ,j+23 ,getcolor());
    }

    for(i = -3*PI-1;i < 0;i +=0.005)
    {
        for(j = -4*PI;j < 4*PI;j += 0.01)
        {
            x = cos(i*2+j)*20+j*30;
            y = sin(i-j*2)*20+i*30*sin(i/2)+sin(x/25)*30;

            putpixel(x+MAXX2 ,y+MAXY2 ,4);

            if(kbhit())
             exit(0);
        }
    }
    getch();
}