/SolarSystem.Wpf/CameraController.cs

using SharpGL;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using System.Windows.Input;

using System.Windows.Media.Media3D;



namespace SolarSystem.Wpf

{

    public class CameraController

    {

        private const Int32 CameraMoveSensitivity = 10;

        private const Int32 CameraRotationSensitivity = 10;



        private Camera camera;

        private Int32 followBodyIndex = -1;

        private System system;

        private Normalizer normalizer;

        private Double height;

        private Double width;

        private Point? lastMousePosition;

        private Boolean mouseControlEnabled;

        private Boolean hudEnabled;



        public CameraController(System system, Normalizer normalizer, Double height, Double width)

        {

            camera = new Camera(new Vector3D(0, 100, 100), new Vector3D(0, 0, 0), new Vector3D(0, Math.Sqrt(2) / 2, -Math.Sqrt(2) / 2));

            this.system = system;

            this.normalizer = normalizer;

            this.height = height;

            this.width = width;

        }



        public void Render(OpenGL gl)

        {

            if (followBodyIndex != -1)

                FollowBody(gl);



            gl.MatrixMode(OpenGL.GL_PROJECTION);

            gl.LoadIdentity();

            gl.Perspective(60.0f, width / height, 0.01d, 1000000d);



            gl.LookAt(

                camera.Position.X,

                camera.Position.Y,

                camera.Position.Z,

                camera.Target.X,

                camera.Target.Y,

                camera.Target.Z,

                camera.Up.X,

                camera.Up.Y,

                camera.Up.Z);



            gl.MatrixMode(OpenGL.GL_MODELVIEW);

        }



        private void FollowBody(OpenGL gl)

        {

            var body = system.Bodies.ElementAt(followBodyIndex);

            var position = new Vector3D(normalizer.NormalizePosition(body.Position[0]), 0, normalizer.NormalizePosition(body.Position[1]));

            camera.FollowBody(position, normalizer.NormalizeRadius(body.Radius));



            if (hudEnabled)

            {

                var planetDisplay = "Planet: " + body.Name;

                var positionDisplay = String.Format(

                    "Position: X={0} Z={1} ", 

                    GetRoundedVectorValue(body.Position[0]), 

                    GetRoundedVectorValue(body.Position[1]));



                var velocityDisplay = String.Format(

                    "Velocity: X={0} Z={1} Magnitude={2}", 

                    GetRoundedVectorValue(body.Velocity[0]),

                    GetRoundedVectorValue(body.Velocity[1]),

                    GetRoundedVectorValue(Math.Sqrt(Math.Pow(body.Velocity[0], 2) + Math.Pow(body.Velocity[1], 2))));



                DrawHudText(gl, planetDisplay, 20);

                DrawHudText(gl, positionDisplay, 40);

                DrawHudText(gl, velocityDisplay, 60);

            }

        }



        private static string GetRoundedVectorValue(Double value)

        {

            return Math.Round(value, 2).ToString("N");

        }



        private static void DrawHudText(OpenGL gl, String text, Int32 topOffset)

        {

            gl.DrawText(10, gl.RenderContextProvider.Height - topOffset, 255, 255, 255, String.Empty, 12f, text);

        }



        public void KeyPress(Key key)

        {

            if (Keyboard.IsKeyDown(Key.W))

                camera.MoveInDirection(CameraMoveSensitivity);



            if (Keyboard.IsKeyDown(Key.S))

                camera.MoveInDirection(-CameraMoveSensitivity);



            if (Keyboard.IsKeyDown(Key.A))

                camera.MoveHorizontally(-CameraMoveSensitivity);



            if (Keyboard.IsKeyDown(Key.D))

                camera.MoveHorizontally(CameraMoveSensitivity);



            if (Keyboard.IsKeyDown(Key.Q))

                camera.MoveVertically(CameraMoveSensitivity);



            if (Keyboard.IsKeyDown(Key.E))

                camera.MoveVertically(-CameraMoveSensitivity);



            if (Keyboard.IsKeyDown(Key.Left))

                camera.Rotate(new Vector3D(CameraRotationSensitivity, 0, 0));



            if (Keyboard.IsKeyDown(Key.Right))

                camera.Rotate(new Vector3D(-CameraRotationSensitivity, 0, 0));



            if (Keyboard.IsKeyDown(Key.Up))

                camera.Rotate(new Vector3D(0, CameraRotationSensitivity, 0));



            if (Keyboard.IsKeyDown(Key.Down))

                camera.Rotate(new Vector3D(0, -CameraRotationSensitivity, 0));



            if (Keyboard.IsKeyDown(Key.M))

                mouseControlEnabled = !mouseControlEnabled;



            if (Keyboard.IsKeyDown(Key.H))

                hudEnabled = !hudEnabled;



            var keyValue = Convert.ToInt32(key);



            if (keyValue == 34)

                followBodyIndex = -1;

            else if (keyValue >= 35 && keyValue <= 42)

                followBodyIndex = keyValue - 34;

        }



        public void MouseMove(Point mousePosition)

        {

            if (mouseControlEnabled == false)

                return;



            if (lastMousePosition.HasValue)

            {

                var movement = new Vector3D(lastMousePosition.Value.X - mousePosition.X, lastMousePosition.Value.Y - mousePosition.Y, 0);



                if (Math.Abs(movement.X) > CameraRotationSensitivity)

                    camera.Rotate(new Vector3D(movement.X / width * 360, 0, 0));



                if (Math.Abs(movement.Y) > CameraRotationSensitivity)

                    camera.Rotate(new Vector3D(0, movement.Y / height * 360, 0));

            }



            lastMousePosition = mousePosition;

        }



        public void RightMouseButtonPressed()

        {

            if (followBodyIndex == 8 || followBodyIndex == -1)

                followBodyIndex = 1;

            else

                followBodyIndex++;

        }

    }

}