smarting about XNA

Game1.cs

// quick hack
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System;

namespace MonoGameTest
{
    public class Game1 : Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        SpriteFont sf;
        Texture2D bulb;
        Texture2D folder;

        Point playerPosition;
        //bool[,] map = { { false, true, false, false}, { false, false, false, true }, { true, true, true, false } };
        bool[,] map = new bool[32,32];

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }


        protected override void Initialize()
        {
            var r = new Random();
            for (int i = 0; i < 32; i++)
            {
                for (int j = 0; j < 32; j++)
                {
                    if (i == 0 && j == 0) continue;
                    map[j, i] = r.Next(0, 3) > 1;
                }
            }
            base.Initialize();
        }


        protected override void LoadContent()
        {
            // Create a new SpriteBatch, which can be used to draw textures.
            spriteBatch = new SpriteBatch(GraphicsDevice);

            sf = Content.Load<SpriteFont>("font");
            bulb = Content.Load<Texture2D>("lightbulb");
            folder = Content.Load<Texture2D>("folder");
        }

        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        void Move(int x, int y)
        {
            for (int i = 0; i < map.GetLength(1); i++)
            {
                for (int j = 0; j < map.GetLength(0); j++)
                {
                    if (map[j, i])
                    {
                        var newPos = new Rectangle(new Point(x, y), new Point(32, 32));
                        var testTile = new Rectangle(new Point(i * 32, j * 32), new Point(32, 32));
                        if (newPos.Intersects(testTile))
                            return;
                    }
                }
            }
            playerPosition = new Point(x, y);
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
                Exit();

            const int by = 2;
            if (Keyboard.GetState().IsKeyDown(Keys.Up))
                Move(playerPosition.X, playerPosition.Y - by);
            if (Keyboard.GetState().IsKeyDown(Keys.Down))
                Move(playerPosition.X, playerPosition.Y + by);
            if (Keyboard.GetState().IsKeyDown(Keys.Left))
                Move(playerPosition.X - by, playerPosition.Y);
            if (Keyboard.GetState().IsKeyDown(Keys.Right))
                Move(playerPosition.X + by, playerPosition.Y);

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);

            spriteBatch.Begin(transformMatrix: Matrix.CreateTranslation(-playerPosition.X + (GraphicsDevice.Viewport.Width / 2), -playerPosition.Y + (GraphicsDevice.Viewport.Height / 2), 0));
            for (int i = 0; i < map.GetLength(1); i++)
            {
                for (int j = 0; j < map.GetLength(0); j++)
                {
                    if (map[j, i])
                    {
                        spriteBatch.Draw(folder, new Rectangle(new Point(i * 32, j * 32), new Point(32, 32)), Color.Beige);
                    }
                }
            }
            spriteBatch.Draw(bulb, new Rectangle(playerPosition, new Point(32, 32)), Color.Beige);
            spriteBatch.End();
            // draw hud
            spriteBatch.Begin();
            spriteBatch.DrawString(sf, playerPosition.ToString(), new Vector2(0, 0), Color.Black);
            spriteBatch.End();

            base.Draw(gameTime);
        }
    }
}