public static bool CollidesWith(this BoundingCircle c, BoundingRectangle r)
{
//var closestX = Math.Max(Math.Min(c.X, r.X + r.Width), r.X);
//var closestY = Math.Max(Math.Min(c.Y, r.Y + r.Height), r.Y);
//return (c.Radius * c.Radius <= Math.Pow(closestX - r.X, 2) + Math.Pow(closestY - r.Y, 2));
var cX = c.X - c.Radius;
var cY = c.Y - c.Radius;
var cRadius = c.Radius;
var rX = r.X;
var rY = r.Y;
var rWidth = r.Width;
var rHeight = r.Height;
// adapted from https://stackoverflow.com/questions/401847/circle-rectangle-collision-detection-intersection
// --------------------------------------------------
var distX = Math.Abs(cX - rX);
var distY = Math.Abs(cY - rY);
if (distX > (rWidth / 2 + cRadius))
{
return(false);
}
if (distY > (rHeight / 2 + cRadius))
{
return(false);
}
if (distX <= (rWidth / 2))
{
return(true);
}
if (distY <= (rHeight / 2))
{
return(true);
}
var cornerDistance_sq = Math.Pow(distX - rWidth / 2, 2) +
Math.Pow(distY - rHeight / 2, 2);
return(cornerDistance_sq <= (cRadius * cRadius));
// --------------------------------------------------
}
public static bool CollidesWith(this BoundingCircle c, Vector2 v)
{
return(v.CollidesWith(c));
}
public static bool CollidesWith(this Vector2 v, BoundingCircle c)
{
return(Math.Pow(c.Radius, 2) >= Math.Pow(v.X - c.X, 2) + Math.Pow(v.Y - c.Y, 2));
}
public static bool CollidesWith(this BoundingRectangle r, BoundingCircle c)
{
return(c.CollidesWith(r));
}
public static bool CollidesWith(this BoundingCircle a, BoundingCircle b)
{
float distance = (a.X - b.X) * (a.X - b.X) + (a.Y - b.Y) * (a.Y - b.Y);
return(distance < (a.Radius + b.Radius) * (a.Radius + b.Radius));
}