ref: 4c96751045a7f0baf6b3a872c20ada9da1bcd5f8
dir: /sys/src/cmd/map/libmap/rectangular.c/
#include <u.h>
#include <libc.h>
#include "map.h"
static double scale;
static int
Xrectangular(struct place *place, double *x, double *y)
{
	*x = -scale*place->wlon.l;
	*y = place->nlat.l;
	return(1);
}
proj
rectangular(double par)
{
	scale = cos(par*RAD);
	if(scale<.1)
		return 0;
	return(Xrectangular);
}