using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace Fake3D
{
    public static class Camera2D
    {
        public static Matrix GetTransformationCenter(Vector2 pos, float zoom, float rotation)
        {
            if (zoom < float.Epsilon) zoom = float.Epsilon;
            return Matrix.CreateTranslation(new Vector3(-pos.X, -pos.Y, 0)) *
                   Matrix.CreateRotationZ(rotation) *
                   Matrix.CreateScale(new Vector3(zoom, zoom, 1)) *
                   Matrix.CreateTranslation(new Vector3(MainGame.graphics.PreferredBackBufferWidth * 0.5f, MainGame.graphics.PreferredBackBufferHeight * 0.5f, 0));
        }

        public static Matrix GetTransformationTopLeft(Vector2 pos, float zoom, float rotation)
        {
            Vector2 newPos = new Vector2(pos.X + (MainGame.graphics.PreferredBackBufferWidth / 2f) / zoom, pos.Y + (MainGame.graphics.PreferredBackBufferHeight / 2f) / zoom);
            
            if (zoom < float.Epsilon) zoom = float.Epsilon;
            return Matrix.CreateTranslation(new Vector3(-newPos.X, -newPos.Y, 0)) *
                   Matrix.CreateRotationZ(rotation) *
                   Matrix.CreateScale(new Vector3(zoom, zoom, 1)) *
                   Matrix.CreateTranslation(new Vector3(MainGame.graphics.PreferredBackBufferWidth * 0.5f, MainGame.graphics.PreferredBackBufferHeight * 0.5f, 0));
        }
    }
}