#include	"defs.h"

/*
 * Add a shape or circle instance
 *
 * input = {-}[shape]^{^}
 *         - flag: scale shape to other than the default size
 *         shape: shape name -- if omitted, the last name typed is used;
 *               if no 'L' entry exists for this name, the shape is drawn as a rectangle
 *         rot: rotation (0-3) of the shape
 *         ^: position of the center-left side of the shape
 * or	 = ^^ for circles.
 *	   ^^: position of centre and point on periphery
 */
achip(head, k, style)
	DL head; 
	CHAR	k;
{
	REG DL	p, q;
	DL1	p1, p2;
	STRING	cnp, rots;
	INT	dir, scaled;
	ITEM	cn;
	INT	k1=k;

	chkhd(head, "cBL");

	if(k=='a') {
		k1='A';
		rdname((cnp = cn), sizeof(cn));
		rots=commasep(cnp);
		if(*cnp == '-'){
			cnp++;
			scaled = 1;
		}
		else
			scaled = 0;
		if(rots) {
			dir=geti(rots)&DIR;
		}
		else
			dir=0;
	} 
	else {
		dir = 0;
		scaled = 1;
		cnp = "";
	}

	/* look for shape at xhairs */
	while(cursor(p1)==SP) {
		copypt(xhairs, p2);
		q=findname('L', cnp);
		if(*cnp && q==0)
			error("shape not found");
		if(scaled || *cnp==0) {
			wchar(p1, '+');
			must(cursor(p2));
		} 
		if( head->type!='L' && (p=finda(head, p1)) ){
			delete(succa(p));
			delete(p);
		} 
		cchip(p1, p2, q, dir, k);
		p = newdl(BEFORE, succ(head->type, head), k, START|dir, p1, style, cnp, nil(STRING));
		newdlw(AFTER, p, k1, END, p2, style);
		destyl = 0;
		showh(head, 0);
	}
}


/*
 * compute rectangle p1, p2 containing a shape instance
 * p1 = 'centre' point
 * p2 = corner point
 *      if p1 and p2 are same point
 *	use default size
 * th = shape header or zero
 * dir is rotation required
 * k = type of shape, 'a' or 'o'.
 */
cchip(p1, p2, th, dir, k)
	REG DL p1, p2;
	DL th;
	INT dir;
	CHAR k;
{
	DL1 r, s, w;
	INT dx, dy, d, v;
	DL tx;

	dx = p1->x - p2->x;
	dy = p1->y - p2->y;
	d = dir;
	if (dx < 0){
		dx = -dx;
		if (dir & 1)
			d = d ^ 1;
		else
			d = 3 - d;
	}
	if (dy < 0){
		dy = -dy;
		if (dir & 1)
			d = 3 - d;
		else
			d = d ^ 1;
	}
	if (k == 'o'){
		if (dy > dx) dx = dy;
		p2->x = p1->x + dx;
		p2->y = p1->y + dx;
		p1->x -= dx;
		p1->y -= dx;
	} 
	else {
		if (th && (tx = succ('x', th))){
			copypt(tx, s);
			if ((tx = succa(tx))->type == 'X')
				copypt(tx, r);
			else
				copypt(point(0, s->y >> 1), r);
		} 
		else {
			copypt(point(dx, dy << 1), s);
			copypt(point(0, dy), r);
		}
		copypt(r, w);
		switch(d){
		case 0:
			break;
		case 1:
		case 2:
			r->y = s->y - r->y;
			if (d == 1)
				break;
		case 3:
			r->x = s->x - r->x;
		}
		if (dir & 1){
			v = r->x; 
			r->x = r->y; 
			r->y = v;
			v = w->x; 
			w->x = w->y; 
			w->y = v;
			v = s->x; 
			s->x = s->y; 
			s->y = v;
		}
		switch(dir){
		case 0:
			break;
		case 1:
		case 2:
			w->x = s->x - w->x;
			if (dir == 1)
				break;
		case 3:
			w->y = s->y - w->y;
			break;
		}
		if (dx == 0 || r->x == 0)
			dx = r->x = 1;
		if (dy == 0 || r->y == 0)
			dy = r->y = 1;
		p1->x -= scale(w->x, dx, r->x);
		p2->x = p1->x + scale(s->x, dx, r->x);
		p1->y -= scale(w->y, dy, r->y);
		p2->y = p1->y + scale(s->y, dy, r->y);
	}
	chkcur(p1);
	chkcur(p2);
}