/// <summary>
/// Is this segment interesects the given segment?
/// </summary>
/// <param name="s">The segment</param>
/// <returns>Returns true if this segment intersects the given segment.</returns>
public bool Intersects(Segment2d s)
{
var aa = s.a - a;
var det = Vector2d.Cross(ab, s.ab);
var t0 = Vector2d.Cross(aa, s.ab) / det;
if (t0 > 0.0 && t0 < 1.0)
{
var t1 = Vector2d.Cross(aa, ab) / det;
return(t1 > 0 && t1 < 1);
}
return(false);
}
/// <summary>
/// Is this segment is inside or intersects the given bounding box?
/// </summary>
/// <param name="r">The bounding box.</param>
/// <returns>Returns true if this segment is inside or intersects the given bounding box.</returns>
public bool Intersects(Box2d r)
{
var b = a + ab;
if (r.Contains(a) || r.Contains(b))
{
return(true);
}
var t = new Box2d(a, b);
if (t.xmin > r.xmax || t.xmax < r.xmin || t.ymin > r.ymax || t.ymax < r.ymin)
{
return(false);
}
var p0 = Vector2d.Cross(ab, new Vector2d(r.xmin, r.ymin) - a);
var p1 = Vector2d.Cross(ab, new Vector2d(r.xmax, r.ymin) - a);
if (p1 * p0 <= 0.0)
{
return(true);
}
var p2 = Vector2d.Cross(ab, new Vector2d(r.xmin, r.ymax) - a);
if (p2 * p0 <= 0.0)
{
return(true);
}
var p3 = Vector2d.Cross(ab, new Vector2d(r.xmax, r.ymax) - a);
if (p3 * p0 <= 0.0)
{
return(true);
}
return(false);
}