#include	"defs.h"

/*
 * Delete the current item.
 *
 * h = zero or current item entry
 * t = item type
 */
delitem(h, t)
	REG DL	h;
	CHAR	t;
{
	chkhd(h, "cwBL");
	moveup(h, adr(succ(h->type, h)) - adr(h));
}

/*
 * Delete all points along a path between two specified points.
 *
 * h = item header
 * input = two cursor positions (the closest points are used)
 */
delpath(h)
	REG DL h;
{
	REG DL	pa, pb;
	DL1	p1, p2;

	chkhd(h, "wBL");
	must(cursor(p1));
	pa = findpt(h, p1);
	if(pa==0)
		error("point not found");
	wchar(pa, '@');
	while(cursor(p2)==SP) {
		pb = findpt(h, p2);
		if(pb==0)
			error("point not found");
		wchar(pb, '@');
		if(rempath(h, pa, pb)==0)
			error("segment not found");
		if((pa=findpt(h,p2))==0)
			break;
	}
}

/*
 * Remove a path
 *
 * h = 'w' entry
 */
LOC INT rempath(h, pa, pb)
	REG DL	h;
	DL	pa, pb;
{
	REG DL	p, q;
	INT	sa, sb;

	q = succa(h);
	while( (p=q)->type!=h->type ) {
		q = succa(p);
		if( (sa=xysame(p,pa)) || (sb=xysame(p,pb)) ) {
			if(sa) {
				if(xysame(q,pb)==0)
					continue;
			}
			elif(sb) {
				if(xysame(q,pa)==0)
					continue;
			}
			if(p->flag&END)
				continue;
			p->flag |= END;
			q->flag |= START;
			h->flag |= DIRTY;
			return(1);
		}
	}
	return(0);
}


/*
 * delete a shape occurence.
 *
 * h is addr of head item
 */
delshape(h)
	REG DL h;
{
	REG DL	p;
	DL1	p1;

	chkhd(h, "cBL");
	must(cursor(p1));
	if(p = finda(h, p1)){
		delete(succa(p));
		delete(p);
	} 
	else
		error("shape not found");
}

/*
 * Delete the closest entry to the cursor of a given type.
 *
 * h = item head
 * t = entry type to delete
 * input = cursor position
 */
delthing(h, t)
	REG DL h;
{
	REG DL	p;
	DL1	p1;

	chkhd(h, "wcLBM");
	must(cursor(p1));
	if(p = findclose(t, h, p1)){
		delete(p);
	}
	else
		error("not found");
}

/*
 * Leave only the end-points of a wire.
 *
 * h = pointer to 'w' entry
 */
delwire(h)
	DL h;
{
	REG DL	p;

	chkhd(h, "w");
	p = h;
	while(p) {
		switch(p->type) {
		case 'e':
		case 'v':
		case 'V':
			delete(p);
			break;
		default:
			p=nexta('w',p);
		}
	}
}

/*
 * delete extent for a shape
 *
 */
delx(h)
	DL	h;
{
	REG DL	p;

	chkhd(h, "L");
	p = h;
	while(p){
		if(p->type=='x')
			delete(p);
		else
			p=nexta('L',p);
	}
}