Box2DX.Collision.EdgeShape.ComputeSubmergedArea C# (CSharp) 메소드

        public override float ComputeSubmergedArea(Vector2 normal, float offset, Transform xf, out Vector2 c)
        {
            //Note that v0 is independent of any details of the specific edge
            //We are relying on v0 being consistent between multiple edges of the same body
            Vector2 v0 = offset * normal;
            //b2Vec2 v0 = xf.position + (offset - b2Dot(normal, xf.position)) * normal;

            Vector2 v1 = xf.TransformPoint(_v1);
            Vector2 v2 = xf.TransformPoint(_v2);

            float d1 = Vector2.Dot(normal, v1) - offset;
            float d2 = Vector2.Dot(normal, v2) - offset;

            if (d1 > 0.0f)
            {
                if (d2 > 0.0f)
                {
                    c = new Vector2();
                    return 0.0f;
                }
                else
                {
                    v1 = -d2 / (d1 - d2) * v1 + d1 / (d1 - d2) * v2;
                }
            }
            else
            {
                if (d2 > 0.0f)
                {
                    v2 = -d2 / (d1 - d2) * v1 + d1 / (d1 - d2) * v2;
                }
                else
                {
                    //Nothing
                }
            }

            // v0,v1,v2 represents a fully submerged triangle
            float k_inv3 = 1.0f / 3.0f;

            // Area weighted centroid
            c = k_inv3 * (v0 + v1 + v2);

            Vector2 e1 = v1 - v0;
            Vector2 e2 = v2 - v0;

            return 0.5f * e1.Cross(e2);
        }