Function:ns2arc

void ns2arc(float px, float py, float pz, float nx, float ny, float nz, 
float sx, float sy, float sz, float deg, int nseg);
</code>

Description

Draw an arc at (px,py,pz) with normal (nx,ny,nz) using the current pen thickness and colour. Vector (sx,sy,sz) gives starting vector from (px,py,pz) and is rotated around the normal in steps (deg/(nseg-1)).

This function is an "extension", and its behaviour for world coordinates which have unequal scales in x, y and/or z is not particularly well defined.

See Also

Code Example

#include <stdio.h>
#include <stdlib.h>
#include "s2plot.h"

int main(int argc, char *argv[])
{
   float px, py, pz;				/* Position */
   float nx, ny, nz;				/* Normal */
   float sx, sy, sz;				/* Starting vector */
   float deg = 180.0;				/* Angular extent */
   int nseg = 48;				/* Number of segments */

   s2opend("/?",argc, argv);			/* Open the display */
   s2swin(-1.,1., -1.,1., -1.,1.);		/* Set the window coordinates */
   s2box("BCDET",0,0,"BCDET",0,0,"BCDET",0,0);	/* Draw coordinate box */

   px = 0.0; py = 0.0; pz = 0.0;		/* Set position */
   nx = 0.0; ny = 1.0; nz = 1.0; 		/* Normal vector */
   sx = 1.0; sy = 0.0; sz = 0.0;		/* Starting vector */

   s2slw(3);					/* Set line width */
   s2sci(S2_PG_YELLOW);				/* Set the colour */
   ns2arc(px,py,pz, nx,ny,nz, sx,sy,sz, deg, nseg);	
						/* Draw the arc */
   s2show(1);					/* Open the s2plot window */
   
   return 1;
}