/// <summary>
/// Gets intersection percent of two rectangles.
/// </summary>
/// <param name="rect1">First rectangle.</param>
/// <param name="rect2">Second rectangle.</param>
/// <returns>Intersection percent (1 - full intersection, 0 - no intersection).</returns>
public static float IntersectionPercent(this RectangleF rect1, RectangleF rect2)
{
float rect1Area = rect1.Width * rect1.Height;
float rect2Area = rect2.Width * rect2.Height;
RectangleF interesectRect = RectangleF.Intersect(rect1, rect2);
float intersectRectArea = interesectRect.Width * interesectRect.Height;
float minRectArea = System.Math.Min(rect1Area, rect2Area);
return((float)intersectRectArea / minRectArea);
}
/// <summary>
/// Inflates the rectangle by specified width and height (can be negative) and automatically clamps rectangle coordinates.
/// </summary>
/// <param name="rect">Rectangle to inflate.</param>
/// <param name="widthScale">Horizontal scale.</param>
/// <param name="heightScale">Vertical scale.</param>
/// <param name="constrainedArea">If specified rectangle region will be clamped.</param>
/// <returns>Inflated rectangle.</returns>
public static RectangleF Inflate(this RectangleF rect, double widthScale, double heightScale, SizeF constrainedArea = default(SizeF))
{
RectangleF newRect = new RectangleF
{
X = (float)(rect.X - rect.Width * widthScale / 2),
Y = (float)(rect.Y - rect.Height * heightScale / 2),
Width = (float)(rect.Width + rect.Width * widthScale),
Height = (float)(rect.Height + rect.Height * heightScale)
};
if (constrainedArea.IsEmpty == false)
{
newRect.Intersect(new RectangleF(new PointF(), constrainedArea));
}
return(newRect);
}
/// <summary>
/// Inflates the rectangle by specified width and height (can be negative) and automatically clamps rectangle coordinates.
/// </summary>
/// <param name="rect">Rectangle to inflate.</param>
/// <param name="widthScale">Horizontal scale.</param>
/// <param name="heightScale">Vertical scale.</param>
/// <param name="constrainedArea">If specified rectangle region will be clamped.</param>
/// <returns>Inflated rectangle.</returns>
public static RectangleF Inflate(this RectangleF rect, double widthScale, double heightScale, SizeF constrainedArea = default(SizeF))
{
RectangleF newRect = new RectangleF
{
X = (float)(rect.X - rect.Width * widthScale / 2),
Y = (float)(rect.Y - rect.Height * heightScale / 2),
Width = (float)(rect.Width + rect.Width * widthScale),
Height = (float)(rect.Height + rect.Height * heightScale)
};
if (constrainedArea.IsEmpty == false)
newRect.Intersect(new RectangleF(new PointF(), constrainedArea));
return newRect;
}
/// <summary>
/// Replaces this rectangle with the intersection of itself and the specified rectangle.
/// </summary>
/// <param name="rect">The rectangle with which to intersect.</param>
public void Intersect(RectangleF rect)
{
this = RectangleF.Intersect(this, rect);
}
