#region Using Statements
using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Storage;
#endregion

namespace XNADemo
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        ContentManager content;
        private Matrix projection;
        private Matrix view;
        private Matrix world;
        private Vector3 cameraPosition = new Vector3(0.0f, 0.0f, 3.0f);
        private Vector3 cameraTarget = Vector3.Zero;
        private Vector3 cameraUpVector = Vector3.Up;
        private VertexPositionNormalTexture[] vertices;
        private short[] indices;
        private FPS fps;
       
        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            content = new ContentManager(Services);
#if PROFILE
            this.IsFixedTimeStep = false;
            graphics.SynchronizeWithVerticalRetrace = false;
            fps = new FPS(this);
            Components.Add(fps);
#endif
#if DEBUG

            fps = new FPS(this);
            Components.Add(fps);
#endif
        }


        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            // TODO: Add your initialization logic here

            base.Initialize();
        }


        /// <summary>
        /// Load your graphics content.  If loadAllContent is true, you should
        /// load content from both ResourceManagementMode pools.  Otherwise, just
        /// load ResourceManagementMode.Manual content.
        /// </summary>
        /// <param name="loadAllContent">Which type of content to load.</param>
        protected override void LoadGraphicsContent(bool loadAllContent)
        {
            InitializeCamera();
            InitializeVertices();
            InitializeIndices();
            if (loadAllContent)
            {
                // TODO: Load any ResourceManagementMode.Automatic content
            }

            // TODO: Load any ResourceManagementMode.Manual content
        }


        /// <summary>
        /// Unload your graphics content.  If unloadAllContent is true, you should
        /// unload content from both ResourceManagementMode pools.  Otherwise, just
        /// unload ResourceManagementMode.Manual content.  Manual content will get
        /// Disposed by the GraphicsDevice during a Reset.
        /// </summary>
        /// <param name="unloadAllContent">Which type of content to unload.</param>
        protected override void UnloadGraphicsContent(bool unloadAllContent)
        {
            if (unloadAllContent)
            {
                // TODO: Unload any ResourceManagementMode.Automatic content
                content.Unload();
            }

            // TODO: Unload any ResourceManagementMode.Manual content
        }


        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            // TODO: Add your update logic here

            base.Update(gameTime);
        }


        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            graphics.GraphicsDevice.Clear(Color.CornflowerBlue);

            // TODO: Add your drawing code here
            world = Matrix.Identity;
            graphics.GraphicsDevice.VertexDeclaration = new
                VertexDeclaration(graphics.GraphicsDevice,
                VertexPositionNormalTexture.VertexElements);

            BasicEffect effect = new BasicEffect(graphics.GraphicsDevice, null);

            world = Matrix.Identity;
            effect.World = world;
            effect.Projection = projection;
            effect.View = view;

            effect.EnableDefaultLighting();
            effect.Begin();

            foreach (EffectPass pass in effect.CurrentTechnique.Passes)
            {
                pass.Begin();
                graphics.GraphicsDevice.DrawUserIndexedPrimitives(
                    PrimitiveType.TriangleList, vertices, 0, vertices.Length,
                    indices, 0, indices.Length / 3);
                pass.End();
            }

            effect.End();
            base.Draw(gameTime);
        }
        void InitializeCamera()
        {
            float aspectRatio = (float)graphics.GraphicsDevice.Viewport.Width /
                (float)graphics.GraphicsDevice.Viewport.Height;
            Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, aspectRatio,
                0.0001f, 1000.0f, out projection);
            Matrix.CreateLookAt(ref cameraPosition, ref cameraTarget,
                ref cameraUpVector, out view);
        }
        private void InitializeVertices()
        {
            Vector3 position;
            Vector2 textureCoordinates;

            vertices = new VertexPositionNormalTexture[4];

            //top left
            position = new Vector3(-1, 1, -3);
            textureCoordinates = new Vector2(0, 0);
            vertices[0] = new VertexPositionNormalTexture(position, Vector3.Forward,
                textureCoordinates);
            //bottom right
            position = new Vector3(1, -1, 0);
            textureCoordinates = new Vector2(1, 1);
            vertices[1] = new VertexPositionNormalTexture(position, Vector3.Forward,
                textureCoordinates);
            //bottom left
            position = new Vector3(-1, -1, -3);
            textureCoordinates = new Vector2(1, 1);
            vertices[2] = new VertexPositionNormalTexture(position, Vector3.Forward,
                textureCoordinates);
            //top right
            position = new Vector3(1, 1, 0);
            textureCoordinates = new Vector2(1, 0);
            vertices[3] = new VertexPositionNormalTexture(position, Vector3.Forward,
                textureCoordinates);
        }
        private void InitializeIndices()
        {
            //6 vertices make up 2 rtriangles which make up our rectangle
            indices = new short[6];

            //triangle 1 (bottom portion)
            indices[0] = 0; //top left
            indices[1] = 1; //bottom right
            indices[2] = 2; //bottom left

            //triangle2 (top portion)
            indices[3] = 0; //top left
            indices[4] = 3; //top right
            indices[5] = 1; //bottom right
        }
    }
}