/PhysicsEngines/JigLib/Helpers.cs

using System.Collections.Generic;

using Delta.Rendering.Models;

using Delta.Utilities.Datatypes;

using JigLibX.Geometry;

using Microsoft.Xna.Framework;

using Color = Delta.Utilities.Datatypes.Color;

using Line = Delta.Rendering.Basics.Drawing.Line;

using Matrix = Delta.Utilities.Datatypes.Matrix;



namespace Delta.PhysicsEngines.JigLib

{

	/// <summary>

	/// Helper class using for comunicate between DeltaEngine and JigLibX.

	/// </summary>

	public static class Helpers

	{

		#region CreateFrom (Static)

		/// <summary>

		/// Creates from.

		/// </summary>

		/// <param name="mesh">The mesh.</param>

		/// <param name="localSpaceMatrix">The local space matrix.</param>

		/// <param name="invertTriangles">if set to <c>true</c> [invert triangles].</param>

		/// <returns>

		/// New created JigLib TriangleMesh shape created from Delta engine mesh.

		/// </returns>

		public static TriangleMesh CreateFrom(Mesh mesh,

			Matrix localSpaceMatrix, bool invertTriangles)

		{

			// extract the data from the physics mesh

			List<Vector3> triangleVertex =

				new List<Vector3>();

			List<TriangleVertexIndices> triangleVertexIndices =

				new List<TriangleVertexIndices>();



			// apply the local transform of the mesh so we get correct coordinates

			Matrix TransMat = localSpaceMatrix;



			Vector transformed;

			Vector3 xnaVector;

			for (int num = 0; num < mesh.Geometry.Data.NumberOfUsedVertices; num++)

			{

				transformed = Vector.Transform(

					mesh.Geometry.Data.GetPosition(num), TransMat);

				JigLibDatatypesMapping.Convert(ref transformed, out xnaVector);

				triangleVertex.Add(xnaVector);

			}



			// set inverted tris if needed

			ushort[] Indices = mesh.Geometry.Data.Indices;

			if (invertTriangles)

			{

				for (int i = 0; i < Indices.Length; i = i + 3)

				{

					triangleVertexIndices.Add(new TriangleVertexIndices(

						Indices[i + 2],

						Indices[i + 1],

						Indices[i]));

				}

			} // if

			else

			{

				for (int i = 0; i < Indices.Length; i = i + 3)

				{

					triangleVertexIndices.Add(new TriangleVertexIndices(

						Indices[i],

						Indices[i + 1],

						Indices[i + 2]));

				}

			} // else



			// create the triangle mesh of the level and add it to the physics world

			TriangleMesh triangleMesh = new TriangleMesh();

			triangleMesh.CreateMesh(triangleVertex, triangleVertexIndices, 1, 1.0f);



			return triangleMesh;

		}

		#endregion



		#region DrawDebug (Static)

		/// <summary>

		/// Draws the debug.

		/// </summary>

		/// <param name="primitive">The primitive.</param>

		public static void DrawDebug(Primitive primitive)

		{

			if (primitive is TriangleMesh)

			{

				DrawTriangleMesh(primitive as TriangleMesh);

			}

		}

		#endregion



		#region Methods (Private)



		#region DrawTriangleMesh

		/// <summary>

		/// Performs debug drawing of JigLibX triangle mesh.

		/// </summary>

		/// <param name="triangleMesh">The triangle mesh to draw.</param>

		private static void DrawTriangleMesh(TriangleMesh triangleMesh)

		{

			Vector3 tempVector;

			Vector v0;

			Vector v1;

			Vector v2;



			for (int i = 0; i < triangleMesh.GetNumTriangles(); ++i)

			{

				IndexedTriangle tri = triangleMesh.GetTriangle(i);



				tempVector = triangleMesh.GetVertex(tri.GetVertexIndex(0));

				JigLibDatatypesMapping.Convert(ref tempVector, out v0);



				tempVector = triangleMesh.GetVertex(tri.GetVertexIndex(1));

				JigLibDatatypesMapping.Convert(ref tempVector, out v1);



				tempVector = triangleMesh.GetVertex(tri.GetVertexIndex(2));

				JigLibDatatypesMapping.Convert(ref tempVector, out v2);



				Line.Draw(v0, v1, Color.Black);

				Line.Draw(v1, v2, Color.Black);

				Line.Draw(v2, v0, Color.Black);

			}

		}

		#endregion



		#endregion

	}

}