/* $Revision$ */

#include <stdlib.h>

void map_init (char *map, int x, int y) {
	int i;

	for (i=0;i<x*y;i++) {
		map[i]=0;
	}
}

char map_ncol (int mc, int n, int dvd);

void map_generate (char *map, int x1,int y1,int x2,int y2) {

	int xn,yn,dxy,p1,p2,p3,p4;

	if ((x2-x1<2) && (y2-y1<2)) return;

	p1 = map[x1*256+y1];
	p2 = map[x1*256+y2];
	p3 = map[x2*256+y1];
	p4 = map[x2*256+y2];

	xn = (x2+x1)/2;  
	yn = (y2+y1)/2;

	dxy = 5*(x2-x1+y2-y1)/3;

	if (map[xn*256+y1] <= 0) map[xn*256+y1] = map_ncol(p1+p3,dxy,2);
	if (map[x1*256+yn] <= 0) map[x1*256+yn] = map_ncol(p1+p2,dxy,2);
	if (map[x2*256+yn] <= 0) map[x2*256+yn] = map_ncol(p3+p4,dxy,2);
	if (map[xn*256+y2] <= 0) map[xn*256+y2] = map_ncol(p2+p4,dxy,2);

	map[xn*256+yn] = map_ncol(p1+p2+p3+p4,dxy,4); 

	map_generate(map, x1,y1,xn,yn);
	map_generate(map, xn,y1,x2,yn);
	map_generate(map, x1,yn,xn,y2);
	map_generate(map, xn,yn,x2,y2);
}

char map_ncol (int mc, int n, int dvd) {
	char loc = 0;

	loc = (mc+n-(int) (2.0*n*rand()/(RAND_MAX+1.0)) )/dvd;
	if (loc < 5) loc = 5;

	return loc;
}