#include	"defs.h"

/*
 * Find another point with the same position.
 *
 * h = item head
 * z = 'e' entry to be checked
 * return = first point with the same coordinates as z but that
 *          is not z, 0 if none
 */
DL another(h, t, z)
	REG DL h, z;
{
	REG DL p;

	p=h;
	while(p=nexta(h->type,p)) {
		if((p->type == t) && xysame(p, z) && (p != z))
			return(p);
	}
	return(nil(DL));
}

/*
 * Compute maximum x/y values
 *
 * h = head item
 * return = max position, 0 if empty shape
 */
DL maxpt(h)
	DL h;
{
	OWN DL1 maxp;
	REG DL p;

	maxp->x = maxp->y = 0;
	p=h;
	while(p=nexta(h->type,p)) {
		switch(p->type) {
		case 'x':
		case 'h':
		case 'v':
		case 'V':
			break;
		default:
			if (p->x > maxp->x)
				maxp->x = p->x;
			if (p->y > maxp->y)
				maxp->y = p->y;
		}
	}
	return(maxp->x ? (maxp) : nil(DL));
}

/*
 * Compute minimum x/y values
 *
 * h = head item
 * return = min position, 0 if empty shape
 */
LOC DL1 minp;
DL minpt(h)
	REG DL h;
{
	REG DL p;

	minp->x = minp->y = MAXINT;
	p=h;
	while(p=nexta(h->type,p)) {
		switch(p->type) {
		case 'x':
		case 'h':
		case 'v':
		case 'V':
			break;
		default:
			if(p->x < minp->x)
				minp->x = p->x;
			if(p->y < minp->y)
				minp->y = p->y;
		}
	}
	return((minp->x == MAXINT) ? nil(DL) : minp);
}

/*
 * linear displacement from given point
 * displacement is display image distance.
 *
 * p = base position
 * xoff = x increment
 * yoff = y increment
 */
DL roffset(p, xoff, yoff)
	DL p;
	INT xoff, yoff;
{
	return(offset(p, xoff >> gscale, yoff >> gscale));
}