Windows Phone Labyrinth

using FarseerPhysics.Common;
using FarseerPhysics.Dynamics;
using FarseerPhysics.Factories;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace FarseerPhysics.SamplesFramework
{
    public class Border
    {
        private Body _anchor;
        private BasicEffect _basicEffect;
        private VertexPositionColorTexture[] _borderVerts;
        private PhysicsGameScreen _screen;
        private World _world;

        public Border(World world, PhysicsGameScreen screen, Viewport viewport)
        {
            _world = world;
            _screen = screen;

            float halfWidth = ConvertUnits.ToSimUnits(viewport.Width) / 2f - 0.75f;
            float halfHeight = ConvertUnits.ToSimUnits(viewport.Height) / 2f - 0.75f;

            Vertices borders = new Vertices(4);
            borders.Add(new Vector2(-halfWidth, halfHeight));
            borders.Add(new Vector2(halfWidth, halfHeight));
            borders.Add(new Vector2(halfWidth, -halfHeight));
            borders.Add(new Vector2(-halfWidth, -halfHeight));

            _anchor = BodyFactory.CreateLoopShape(_world, borders);
            _anchor.CollisionCategories = Category.All;
            _anchor.CollidesWith = Category.All;

            _basicEffect = new BasicEffect(_screen.ScreenManager.GraphicsDevice);
            _basicEffect.VertexColorEnabled = true;
            _basicEffect.TextureEnabled = true;
            _basicEffect.Texture = _screen.ScreenManager.Content.Load<Texture2D>("Materials/pavement");

            VertexPositionColorTexture[] vertice = new VertexPositionColorTexture[8];
            vertice[0] = new VertexPositionColorTexture(new Vector3(-halfWidth, -halfHeight, 0f),
                                                        Color.LightGray, new Vector2(-halfWidth, -halfHeight) / 5.25f);
            vertice[1] = new VertexPositionColorTexture(new Vector3(halfWidth, -halfHeight, 0f),
                                                        Color.LightGray, new Vector2(halfWidth, -halfHeight) / 5.25f);
            vertice[2] = new VertexPositionColorTexture(new Vector3(halfWidth, halfHeight, 0f),
                                                        Color.LightGray, new Vector2(halfWidth, halfHeight) / 5.25f);
            vertice[3] = new VertexPositionColorTexture(new Vector3(-halfWidth, halfHeight, 0f),
                                                        Color.LightGray, new Vector2(-halfWidth, halfHeight) / 5.25f);
            vertice[4] = new VertexPositionColorTexture(new Vector3(-halfWidth - 2f, -halfHeight - 2f, 0f),
                                                        Color.LightGray,
                                                        new Vector2(-halfWidth - 2f, -halfHeight - 2f) / 5.25f);
            vertice[5] = new VertexPositionColorTexture(new Vector3(halfWidth + 2f, -halfHeight - 2f, 0f),
                                                        Color.LightGray,
                                                        new Vector2(halfWidth + 2f, -halfHeight - 2f) / 5.25f);
            vertice[6] = new VertexPositionColorTexture(new Vector3(halfWidth + 2f, halfHeight + 2f, 0f),
                                                        Color.LightGray,
                                                        new Vector2(halfWidth + 2f, halfHeight + 2f) / 5.25f);
            vertice[7] = new VertexPositionColorTexture(new Vector3(-halfWidth - 2f, halfHeight + 2f, 0f),
                                                        Color.LightGray,
                                                        new Vector2(-halfWidth - 2f, halfHeight + 2f) / 5.25f);

            _borderVerts = new VertexPositionColorTexture[24];
            _borderVerts[0] = vertice[0];
            _borderVerts[1] = vertice[5];
            _borderVerts[2] = vertice[4];
            _borderVerts[3] = vertice[0];
            _borderVerts[4] = vertice[1];
            _borderVerts[5] = vertice[5];
            _borderVerts[6] = vertice[1];
            _borderVerts[7] = vertice[6];
            _borderVerts[8] = vertice[5];
            _borderVerts[9] = vertice[1];
            _borderVerts[10] = vertice[2];
            _borderVerts[11] = vertice[6];
            _borderVerts[12] = vertice[2];
            _borderVerts[13] = vertice[7];
            _borderVerts[14] = vertice[6];
            _borderVerts[15] = vertice[2];
            _borderVerts[16] = vertice[3];
            _borderVerts[17] = vertice[7];
            _borderVerts[18] = vertice[3];
            _borderVerts[19] = vertice[4];
            _borderVerts[20] = vertice[7];
            _borderVerts[21] = vertice[3];
            _borderVerts[22] = vertice[0];
            _borderVerts[23] = vertice[4];
        }

        public void Draw()
        {
            GraphicsDevice device = _screen.ScreenManager.GraphicsDevice;
            LineBatch batch = _screen.ScreenManager.LineBatch;

            device.SamplerStates[0] = SamplerState.AnisotropicWrap;
            device.RasterizerState = RasterizerState.CullNone;
            _basicEffect.Projection = _screen.Camera.SimProjection;
            _basicEffect.View = _screen.Camera.SimView;
            _basicEffect.CurrentTechnique.Passes[0].Apply();

            device.DrawUserPrimitives(PrimitiveType.TriangleList, _borderVerts, 0, 8);

            batch.Begin(_screen.Camera.SimProjection, _screen.Camera.SimView);
            batch.DrawLineShape(_anchor.FixtureList[0].Shape);
            batch.End();
        }
    }
}