Game1.cpp

using BEPUphysics;
using BEPUphysics.Entities.Prefabs;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace Physics
{
	public class Game1 : Game
	{
		GraphicsDeviceManager graphics;
		SpriteBatch spriteBatch;

		Space world;
		Model cube, sphere;

		Box cubeBox, sphereBox;

		Matrix viewMatrix, projectionMatrix;

		KeyboardState current, previous;

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

			this.IsMouseVisible = true;
			this.graphics.PreferredBackBufferWidth = 1280;
			this.graphics.PreferredBackBufferHeight = 720;
		}

		protected override void Initialize()
		{
			world = new Space();

			viewMatrix = Matrix.CreateLookAt(new Vector3(0f, 4f, -10f), new Vector3(0f, 0f, 0f), Vector3.Up);
			projectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(65f), GraphicsDevice.DisplayMode.AspectRatio, 0.5f, 1000f);

			base.Initialize();
		}

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

			// Load models
			cube = this.Content.Load<Model>("Cube");
			sphere = this.Content.Load<Model>("Cube");

			cubeBox = new Box(BEPUutilities.Vector3.Zero, 2f, 2f, 2f);
			sphereBox = new Box(new BEPUutilities.Vector3(0f, 4f, 0f), 2f, 2f, 2f, 10f);

			world.Add(cubeBox);
			world.Add(sphereBox);

			world.ForceUpdater.Gravity = new BEPUutilities.Vector3(0f, -20f, 0f);
		}

		protected override void UnloadContent()
		{
			// TODO: Unload any non ContentManager content here
			spriteBatch.Dispose();
			Content.Dispose();
		}

		protected override void Update(GameTime gameTime)
		{
			if (Keyboard.GetState().IsKeyDown(Keys.Escape))
				Exit();

			previous = current;
			current = Keyboard.GetState();

			if(current != previous)
			{
				if (Keyboard.GetState().IsKeyDown(Keys.Left))
					sphereBox.LinearVelocity += new BEPUutilities.Vector3(5f, 0f, 0f);

				if (Keyboard.GetState().IsKeyDown(Keys.Right))
					sphereBox.LinearVelocity -= new BEPUutilities.Vector3(5f, 0f, 0f);

				if (Keyboard.GetState().IsKeyDown(Keys.Space))
					sphereBox.LinearVelocity += new BEPUutilities.Vector3(0f, 5f, 0f);
			}
			
			// Update the world
			world.Update();

			base.Update(gameTime);
		}

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

			foreach(ModelMesh mesh in cube.Meshes)
			{
				foreach(BasicEffect effect in mesh.Effects)
				{
					effect.View = viewMatrix;
					effect.World = Matrix.CreateTranslation(new Vector3(cubeBox.Position.X, cubeBox.Position.Y, cubeBox.Position.Z));
					effect.Projection = projectionMatrix;

					effect.EnableDefaultLighting();
				}

				mesh.Draw();
			}

			foreach (ModelMesh mesh in sphere.Meshes)
			{
				foreach (BasicEffect effect in mesh.Effects)
				{
					effect.View = viewMatrix;
					effect.World = Matrix.CreateTranslation(new Vector3(sphereBox.Position.X, sphereBox.Position.Y, sphereBox.Position.Z));
					effect.Projection = projectionMatrix;

					effect.EnableDefaultLighting();
				}

				mesh.Draw();
			}

			base.Draw(gameTime);
		}
	}
}