private static Line ClosestLine(Rect rect, Point p)
{
var angle = new Vector(1, 1).AngleTo(p.VectorTo(rect.CenterPoint()));
if (angle >= 0 && angle <= 90)
{
return rect.TopLine();
}
if (angle >= 90 && angle <= 180)
{
return rect.RightLine();
}
if (angle >= -90 && angle <= 0)
{
return rect.LeftLine();
}
if (angle >= -180 && angle <= -90)
{
return rect.BottomLine();
}
throw new InvalidOperationException("Could not find closest line");
}
private Point? GetPointOnTarget(Point sourceMidPoint, Rect target)
{
switch (this.Vertical)
{
case VerticalPlacement.Auto:
switch (this.Horizontal)
{
case HorizontalPlacement.Auto:
var closestLine = ClosestLine(target, sourceMidPoint);
return AutoPoint(sourceMidPoint.LineTo(target.CenterPoint()), closestLine);
case HorizontalPlacement.Left:
return AutoPoint(sourceMidPoint.LineTo(target.CenterPoint()), target.LeftLine());
case HorizontalPlacement.Center:
return sourceMidPoint.Closest(target.BottomLine(), target.TopLine())
.MidPoint;
case HorizontalPlacement.Right:
return AutoPoint(sourceMidPoint.LineTo(target.CenterPoint()), target.RightLine());
default:
throw new ArgumentOutOfRangeException();
}
case VerticalPlacement.Top:
switch (this.Horizontal)
{
case HorizontalPlacement.Auto:
return AutoPoint(sourceMidPoint.LineTo(target.CenterPoint()), target.TopLine());
case HorizontalPlacement.Left:
return target.TopLeft;
case HorizontalPlacement.Center:
return PointExt.MidPoint(target.TopLeft, target.TopRight);
case HorizontalPlacement.Right:
return target.TopRight;
default:
throw new ArgumentOutOfRangeException();
}
case VerticalPlacement.Center:
switch (this.Horizontal)
{
case HorizontalPlacement.Auto:
return sourceMidPoint.Closest(target.LeftLine(), target.RightLine())
.MidPoint;
case HorizontalPlacement.Left:
return PointExt.MidPoint(target.BottomLeft, target.TopLeft);
case HorizontalPlacement.Center:
return PointExt.MidPoint(target.TopLeft, target.BottomRight);
case HorizontalPlacement.Right:
return PointExt.MidPoint(target.BottomRight, target.TopRight);
default:
throw new ArgumentOutOfRangeException();
}
case VerticalPlacement.Bottom:
switch (this.Horizontal)
{
case HorizontalPlacement.Auto:
return AutoPoint(sourceMidPoint.LineTo(target.CenterPoint()), target.BottomLine());
case HorizontalPlacement.Left:
return target.BottomLeft;
case HorizontalPlacement.Center:
return PointExt.MidPoint(target.BottomLeft, target.BottomRight);
case HorizontalPlacement.Right:
return target.BottomRight;
default:
throw new ArgumentOutOfRangeException();
}
default:
throw new ArgumentOutOfRangeException();
}
}
internal Point? FirstIntersectionWith(Rect rectangle)
{
var quadrant = rectangle.Contains(this.Point)
? this.Direction.Quadrant()
: this.Direction.Negated().Quadrant();
switch (quadrant)
{
case Quadrant.NegativeXPositiveY:
return IntersectionPoint(this, rectangle.LeftLine(), true) ??
IntersectionPoint(this, rectangle.BottomLine(), true);
case Quadrant.PositiveXPositiveY:
return IntersectionPoint(this, rectangle.RightLine(), true) ??
IntersectionPoint(this, rectangle.BottomLine(), true);
case Quadrant.PositiveXNegativeY:
return IntersectionPoint(this, rectangle.RightLine(), true) ??
IntersectionPoint(this, rectangle.TopLine(), true);
case Quadrant.NegativeXNegativeY:
return IntersectionPoint(this, rectangle.LeftLine(), true) ??
IntersectionPoint(this, rectangle.TopLine(), true);
default:
throw new ArgumentOutOfRangeException();
}
}