Quad.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using StarsGame.Universe_Objects.Planets;

namespace StarsGame
{
    public class Quad
    {
        public PlanetGeometry.FACING_DIRECTION FaceName;

        private Triangle[] triangles;
        public Triangle[] Triangles
        {
            get { return triangles; }
        }

        private VertexPositionNormalTexture[] corners;
        public VertexPositionNormalTexture[] Corners
        {
            get { return corners; }
            set { corners = value; }
        }

        private VertexPositionNormalColor[] colorCorners;
        public VertexPositionNormalColor[] ColorCorners
        {
            get { return colorCorners; }
            set { colorCorners = value; }
        }

        public Quad(VertexPositionNormalTexture[] corners, PlanetGeometry.FACING_DIRECTION faceName)
        {
            this.corners = corners;
            triangles = CreateTriangles();

            this.FaceName = faceName;
            //calc normal from face name
            GenerateNormal();
        }

        public Quad()
        {

        }

        private Triangle[] CreateTriangles()
        {
            Triangle tri1 = new Triangle(
                new int[3] { 0, 1, 3 }); //top left, bottom right, bottom left
            Triangle tri2 = new Triangle(
                new int[3] { 1, 2, 3 }); //top right, bottom right, bottom left
            return new Triangle[2] { tri1, tri2 };
        }

        public Vector3[] GetCornerPositions()
        {
            Vector3[] positions = new Vector3[4];
            for (int p = 0; p < 4; p++)
            {
                positions[p] = corners[p].Position;
            }
            return positions;
        }

        public void CreateColorCorners(Color color)
        {
            colorCorners = new VertexPositionNormalColor[4];
            for (int c = 0; c < 4; c++)
            {
                colorCorners[c] = new VertexPositionNormalColor(corners[c].Position, color, corners[c].Normal);
            }
        }

        public bool CorrectTriangles(Vector3 centerOfBlock)
        {
            bool a = triangles[0].CheckIndices(this, centerOfBlock, FaceName);
            bool b = triangles[1].CheckIndices(this, centerOfBlock, FaceName);
            if (!(a && b))
            {
                CreateColorCorners(Color.Red);
                return false;
            }
            else
            {
                return true;
            }
        }

        private void GenerateNormal()
        {
            Vector3[] cornerPositions = GetCornerPositions();
            Vector3 a = cornerPositions[2] - cornerPositions[0];
            Vector3 b = cornerPositions[2] - cornerPositions[1];
            Vector3 normal = Vector3.Cross(a, b);
            for (int v = 0; v < corners.Length; v++)
            {
                corners[v].Normal = normal;
            }
        }

    }
}