Nez.PhysicsShapes.ShapeCollisions.lineToCircle C# (CSharp) Method

		public static bool lineToCircle( Vector2 start, Vector2 end, Circle s, out RaycastHit hit )
		{
			hit = new RaycastHit();

			// calculate the length here and normalize d separately since we will need it to get the fraction if we have a hit
			var lineLength = Vector2.Distance( start, end );
			var d = ( end - start ) / lineLength;
			var m = start - s.position;
			var b = Vector2.Dot( m, d );
			var c = Vector2.Dot( m, m ) - s.radius * s.radius;

			// exit if r's origin outside of s (c > 0) and r pointing away from s (b > 0)
			if( c > 0f && b > 0f )
				return false;

			var discr = b * b - c;

			// a negative descriminant means the line misses the circle
			if( discr < 0 )
				return false;

			// ray intersects circle. calculate details now.
			hit.fraction = -b - Mathf.sqrt( discr );

			// if fraction is negative, ray started inside circle so clamp fraction to 0
			if( hit.fraction < 0 )
				hit.fraction = 0;

			hit.point = start + hit.fraction * d;
			Vector2.Distance( ref start, ref hit.point, out hit.distance );
			hit.normal = Vector2.Normalize( hit.point - s.position );
			hit.fraction = hit.distance / lineLength;

			return true;
		}

 public override bool collidesWithLine(Vector2 start, Vector2 end, out RaycastHit hit)
 {
     hit = new RaycastHit();
     return(ShapeCollisions.lineToCircle(start, end, this, out hit));
 }