drawpoly

Draws the outline of a polygon.

Defined in header <graphics.h>

Syntax

#include <graphics.h>
void far drawpoly(int numpoints, int far *polypoints);

Portability

Remarks

drawpoly draws a polygon with numpoints points, using the current line style and color.

*polypoints points to a sequence of (numpoints x 2) integers. Each pair of integers gives the x and y coordinates of a point on the polygon.

■^

In order to draw a closed figure with n vertices, you must pass n + 1 coordinates to drawpoly where the nth coordinate is equal to the 0th.

Return value

None.

See also

• fillpoly
• floodfill
• graphresult
• setwritemode

Example

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
   /* request autodetection  */
   int gdriver = DETECT, gmode,  errorcode;
   int maxx, maxy;

   int poly[l(     /* our polygon  array */

   /* initialize graphics and  local variables */
   initgraphl&gdriver, &gmode,  "");

   /* read result of initialization  */
   errorcode = graphresult ();
   if (errorcode != grOk) { /* an error occurred */
     ■ printf("Graphics error: %s\n", grapherrormsg(errorcode))
      printf("Press any key to halt:");
      getchO ;
      exit(l)              /* terminate  with an error code */

   maxx = getmaxx ();
   maxy = getmaxy();
   poly[0] = 20;           /*  first vertex */
   poly[l] = maxy / 2;
   poly[2] = maxx - 20;    /* second vertex  */
   poly[3] = 20;
   poly[4] = maxx - 50;    /* third vertex  */
   poly[5] = maxy - 20;
   poly[6] = maxx / 2;     /*  fourth vertex */
   poly[7] = maxy / 2;
   poly[8] = poly[0];      /* drawpoly  doesn't automatically close */
   poly[9] = poly[l];      /* the polygon,  so we close it */

   drawpoly(5, poly);   /* draw the polygon  */

   /* clean up */
   getchO ;
   closegraphO ;
return

Differences from modern implementations

Nothing recorded yet.

Modern references

• Microsoft C runtime (search)

These are search links, not yet checked by hand.

Stable link: /3.1/graphics.h/drawpoly/ · short form /3.1/drawpoly/