/* 
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

#include <u.h>
#include <libc.h>
#include "map.h"

static struct coord stdpar;

static int
Xconic(struct place *place, double *x, double *y)
{
	double r;
	if(fabs(place->nlat.l-stdpar.l) > 80.*RAD)
		return(-1);
	r = stdpar.c/stdpar.s - tan(place->nlat.l - stdpar.l);
	*x = - r*sin(place->wlon.l * stdpar.s);
	*y = - r*cos(place->wlon.l * stdpar.s);
	if(r>3) return(0);
	return(1);
}

proj
conic(double par)
{
	if(fabs(par) <.1)
		return(Xcylindrical);
	deg2rad(par, &stdpar);
	return(Xconic);
}