#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>

#include <bt.h>
#include <map.h>

#include "dat.h"

Point cardinals[] = {
[WEST]	{ -1,  0 },
[SOUTH]	{  0,  1 },
[NORTH]	{  0, -1 },
[EAST]	{  1,  0 },
[NODIR]	{  0,  0 },
};

/* pick a random point along some side of the rect, no corners */
Point
pickpoint(Rectangle r, int dir, int inset)
{
	Point p;

	assert(inset >= 0);

	switch(dir){
	case WEST:
		p = Pt(r.min.x, r.min.y + nrand(Dy(r)-inset) + inset);
		break;
	case SOUTH:
		p = Pt(r.min.x + nrand(Dx(r)-inset) + inset, r.max.y);
		break;
	case NORTH:
		p = Pt(r.min.x + nrand(Dx(r)-inset) + inset, r.min.y);
		break;
	case EAST:
		p = Pt(r.max.x, r.min.y + nrand(Dy(r)-inset) + inset);
		break;
	default:
		abort();
	}

	r.max.x++;
	r.max.y++;
	assert(ptinrect(p, r));

	return p;
}

int
roll(int count, int sides)
{
	int d;
	d = 0;
	while(count--> 0)
		d += 1+nrand(sides);
	return d;
}

int
parseroll(char *str, int *count, int *sides)
{
	int i;
	char *f[2];

	if(str == nil || count == nil || sides == nil)
		return 0;

	i = gettokens(str, f, 2, "d");
	if(i != 2)
		return 0;

	*count = atoi(f[0]);
	*sides = atoi(f[1]);
	return 1;
}

int
min(int a, int b)
{
	if(a < b)
		return a;
	return b;
}

int
max(int a, int b)
{
	if(a > b)
		return a;
	return b;
}

/* needed because p9p doesn't have frand for some reason. */
#define	MASK	0x7fffffffL
#define	NORM	(1.0/(1.0+MASK))

double
frand(void)
{
	double x;

	do {
		x = lrand() * NORM;
		x = (x + lrand()) * NORM;
	} while(x >= 1);
	return x;
}

void*
emalloc(ulong size)
{
	void *p;

	p = mallocz(size, 1);
	if(p == nil)
		sysfatal("out of memory allocating %lud bytes", size);
	setmalloctag(p, getcallerpc(&size));
	return p;
}