dda.c

C 语言算法

 /*How to init graphics mode*/
#include <stdio.h>
#include <graphics.h>
#include <math.h>
void DDA(int x0,int y0,int x1,int y1)
{
float x,y,dx,dy;
float m;
dx=x1-x0;
dy=y1-y0;
y=y0;
if(x0==x1)
  for(y=y0;y<=y1;y++)
  {
    putpixel(x1,y,RED);

  }
else
  {
    m=dy/dx;
    if(fabs(m)<=1)
     {
       for(x=x0;x<=x1;x++)
	{
	putpixel(x,y,GREEN);
	y+=m;
	}
     }
    else
     {
      m=dx/dy;
      for(y=y0;y<=y1;y++)
       {
       putpixel(x,y,YELLOW);
       x+=m;
       }
     }
  }
}
main()
{
int gd,gm;
int x0,y0,x1,y1;

printf(" Input integer x0,y0,x1,y1:");
scanf("%d,%d,%d,%d",&x0,&y0,&x1,&y1);

gd=DETECT;
initgraph(&gd,&gm,"c:\\tc\\bgi");
cleardevice();
DDA(x0,y0,x1,y1);
getchar();
getchar();
closegraph();
}