#ifndef lint
static char rcsid[] =
    "@(#) $Header: /src/X11/contrib/demos/xphoon/RCS/fullmoon.c,v 1.5 90/06/27 10:29:59 tim Exp $ (LBL)";
#endif

/*
** Copyright (C) 1988 by Jef Poskanzer and Craig Leres.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#include <X11/Xlib.h>
#include <bigfullmoon.xbm>
#define CENTER_X 800
#define CENTER_Y 645
#define RADIUS 378

checkbitmapsize(w, h)
	int *w, *h;
{
	int minw, minh;
	minw = ((CENTER_X + RADIUS + 7)/8 - (CENTER_X - RADIUS)/8) * 8;
	minh = 2*RADIUS;
	if (*w < minw) *w = minw;
	if (*h < minh) *h = minh;
	if (*w > bigfullmoon_width)  *w = bigfullmoon_width;
	if (*h > bigfullmoon_height) *h = bigfullmoon_height;
}

getbitmap(w, h, bits, cx, cy, r)
	int w, h;
	char *bits;
	int *cx, *cy, *r;
{
	int bx, by;	/* origin of fullmoon bitmap in display coordinates */
	int fl, dl;	/* length of scan line in bytes of fullmoon, display */
	int fb;		/* useable bytes of image */
	int y;		/* Current position in display bitmap */
	char *fbp, *dbp;	/* Pointers to current bitmap position */

	dl = (w+7)/8;
	fl = (bigfullmoon_width+7)/8;
	fb = (bigfullmoon_width)/8;

	bx = (dl-fb)/2;
	by = (h-bigfullmoon_height)/2;
	if (h < 900) by -= 5;		/* center fullmoon vertically */

	*cx = CENTER_X+bx*8;
	*cy = CENTER_Y+by;
	*r = RADIUS;

	dbp = bits;
	for (y=0; y<h; y++){
		fbp = bigfullmoon_bits + (y-by)*fl - bx;
		bcopy(fbp,dbp,dl);
		dbp += dl;
	}
}