boundsOf function
Compute the axis-aligned bounding rect of a set of offsets.
Implementation
Rect boundsOf(Iterable<Offset> pts) {
final it = pts.iterator..moveNext();
double minX = it.current.dx, maxX = it.current.dx;
double minY = it.current.dy, maxY = it.current.dy;
while (it.moveNext()) {
final p = it.current;
if (p.dx < minX) minX = p.dx;
if (p.dx > maxX) maxX = p.dx;
if (p.dy < minY) minY = p.dy;
if (p.dy > maxY) maxY = p.dy;
}
return Rect.fromLTRB(minX, minY, maxX, maxY);
}