ExampleInput.cs

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;
using System;

namespace Game1
{
    internal static class ExampleInput
    {
        static MouseState previousMouseState;
        #region Extension Methods
        internal static int DeltaX(this MouseState mouseState)
        {
            return Mouse.GetState().X - previousMouseState.X;
        }
        internal static int DeltaY(this MouseState mouseState)
        {
            return Mouse.GetState().Y - previousMouseState.Y;
        }
        internal static int DeltaScrollWheelValue(this MouseState mouseState)
        {
            return Mouse.GetState().ScrollWheelValue - previousMouseState.ScrollWheelValue;
        }
        internal static bool Moving(this MouseState mouseState)
        {
            return (Mouse.GetState().X != previousMouseState.X || Mouse.GetState().Y != previousMouseState.Y) ? true : !true;
        }
        #endregion
        internal static void Update()
        {
            CameraMovement();
            // Call last so all other methods have previous states when called.
            previousMouseState = Mouse.GetState();
        }
        static void CameraMovement()
        {
            if (Mouse.GetState().DeltaScrollWheelValue() != 0)
            {
                Game1.mainCamera.destination += (Mouse.GetState().DeltaScrollWheelValue() * (float)Game1.gameTime.ElapsedGameTime.TotalSeconds * Game1.mainCamera.transform.Matrix.Forward * 100);
                Console.Clear();
                Console.WriteLine("Input manager thinks forward is: " + Game1.mainCamera.View.Forward);
            }
            if (Mouse.GetState().DeltaX() != 0 && Mouse.GetState().MiddleButton == ButtonState.Pressed)
            {
                Game1.mainCamera.destination += Mouse.GetState().DeltaX() * (float)Game1.gameTime.ElapsedGameTime.TotalSeconds * Game1.mainCamera.View.Right * 100;
            }
            if (Mouse.GetState().DeltaY() != 0 && Mouse.GetState().MiddleButton == ButtonState.Pressed)
            {
                Game1.mainCamera.destination += -Mouse.GetState().DeltaY() * (float)Game1.gameTime.ElapsedGameTime.TotalSeconds * Vector3.Up * 100;
            }
            if (Mouse.GetState().Moving() && Keyboard.GetState().IsKeyDown(Keys.LeftAlt))
            {
                // Rotate the camera.
                // **This is the part I have no clue how to rotate properly**
                Game1.mainCamera.transform.Rotation = Quaternion.Concatenate(Game1.mainCamera.transform.Rotation, Quaternion.CreateFromAxisAngle(Game1.mainCamera.View.Up, Mouse.GetState().DeltaX() * (float)Game1.gameTime.ElapsedGameTime.TotalSeconds * 15));
            }
        }
    }
}