using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Azimuth;
using Lodestone;
using UnitTestSharp;

namespace Lodestone.UnitTests.DiscreteCollisionDetection
{
	class PointToTriangle : TestFixture
	{
		public static readonly Vector a = new Vector(0, 1);
		public static readonly Vector b = new Vector(-1, 0);
		public static readonly Vector c = new Vector(1, 0);
		public static readonly Vector abMid = (a + b) / 2;

		Scalar wA, wB, wC;

		public void VertexA()
		{
			Vector p = a * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

			CheckEqual(a, pPrime);
			CheckEqual(1, wA);
			CheckEqual(0, wB);
			CheckEqual(0, wC);
		}

		public void VertexB()
		{
			Vector p = a * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(b, a, c, p, out wA, out wB, out wC);

			CheckEqual(a, pPrime);
			CheckEqual(0, wA);
			CheckEqual(1, wB);
			CheckEqual(0, wC);
		}

		public void VertexC()
		{
			Vector p = a * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(c, b, a, p, out wA, out wB, out wC);

			CheckEqual(a, pPrime);
			CheckEqual(0, wA);
			CheckEqual(0, wB);
			CheckEqual(1, wC);
		}

		public void AB()
		{
			Vector p = abMid * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

			CheckEqual(abMid, pPrime);
			CheckEqual(0.5, wA);
			CheckEqual(0.5, wB);
			CheckEqual(0, wC);
		}

		public void BC()
		{
			Vector p = abMid * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(c, b, a, p, out wA, out wB, out wC);

			CheckEqual(abMid, pPrime);
			CheckEqual(0, wA);
			CheckEqual(0.5, wB);
			CheckEqual(0.5, wC);
		}

		public void CA()
		{
			Vector p = abMid * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(a, c, b, p, out wA, out wB, out wC);

			CheckEqual(abMid, pPrime);
			CheckEqual(0.5, wA);
			CheckEqual(0, wB);
			CheckEqual(0.5, wC);
		}

		public void Inside()
		{
			Vector p = (a + b + c) / 3;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

			CheckEqual(p, pPrime);
			CheckEqual(1.0 / 3.0, wA);
			CheckEqual(1.0 / 3.0, wB);
			CheckEqual(1.0 / 3.0, wC);
		}

		public void Degenerate()
		{
			Vector p = a * 10;
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(a, a, a, p, out wA, out wB, out wC);

			CheckEqual(a, pPrime);
		}

		public void Colinear()
		{
			Vector a = new Vector(-1, 0);
			Vector b = new Vector(0, 0);
			Vector c = new Vector(1, 0);

			Vector p = new Vector(0.5, 10);
			Vector pPrime = Lodestone.DiscreteCollisionDetection.PointToTriangle.ClosestPointOnTriangleToPoint(a, b, c, p, out wA, out wB, out wC);

			CheckEqual(new Vector(0.5, 0), pPrime);
		}
	}
}