shithub: vcrop

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clamp cropped area to image bounds

	garbage was being captured when the crop rectangle was outside of image
	bounds. We now ensure that the cropped area is constrained within image
	rectangle.

--- a/vcrop.c

+++ b/vcrop.c

@@ -44,15 +44,24 @@

 crop(Mouse *m)

 {

 	Rectangle r;

+	Point o;

 	Image *i;

 	r = egetrect(1, m);

 	if(eqrect(r, ZR) || badrect(r) || (Dx(r)<Threshold && Dy(r)<Threshold))

 		return;

-	i = allocimage(display, Rect(0,0,Dx(r),Dy(r)), screen->chan, 0, DNofill);

+	o = subpt(r.min, screen->r.min);

+	o = addpt(n->r.min, o);

+	o = subpt(o, addpt(n->r.min, pos));

+	/* clamp rect to image bounds */

+	if(o.x < n->r.min.x) o.x = n->r.min.x;

+	if(o.y < n->r.min.y) o.y = n->r.min.y;

+	if((o.x + Dx(r)) > n->r.max.x) r.max.x = r.min.x + n->r.max.x - o.x;

+	if((o.y + Dy(r)) > n->r.max.y) r.max.y = r.min.y + n->r.max.y - o.y;

+	i = allocimage(display, r, screen->chan, 0, DNofill);

 	if(i==nil)

 		sysfatal("allocimage: %r");

-	draw(i, i->r, screen, nil, r.min);

+	draw(i, i->r, n, nil, o);

 	if(p)

 		freeimage(p);

 	p = n;