MoveComponent.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ClassBasedES
{
    public struct vec2
    {
        public float x;
        public float y;

        public static vec2 operator +(vec2 value1, vec2 value2)
        {
            return new vec2() { x = value1.x + value2.x, y = value1.y + value2.y };
        }
    }

    /// <summary>
    /// Static component classes = no singleton needed, we just use static methods
    /// </summary>
    public class MoveComponent : IComponent
    {
        /*IComponent  begin */
        public static void addComponent(entity e)
        {
            myEntitiesPositions[e] = new vec2() {x=0,y=0};
            myEntitiesVelocities[e] = new vec2() {x=0,y=0};
        }
        public static void removeComponent(entity e)
        {
            myEntitiesPositions.Remove(e);
            myEntitiesVelocities.Remove(e);
        }
        public static List<entity> getEntities()
        {
            var retval = new List<entity>();
            retval.AddRange(myEntitiesPositions.Keys);
            return retval;
        }
        /*IComponent  end */




        static vec2 gravity = new vec2() { x = 0, y = 0.9f };

        //the only storage of entties (Guids) is in components
        //  If we used indexed lists/arrays, the index would change = more bug prone
        //  I just prefer clearer and concise code.
        public static Dictionary<entity, vec2> myEntitiesPositions = new Dictionary<entity,vec2>();
        public static Dictionary<entity, vec2> myEntitiesVelocities = new Dictionary<entity, vec2>();

        public static void moveEntities()
        {
            foreach (var entity in myEntitiesPositions)
            {
                myEntitiesVelocities[entity.Key] += gravity;
                myEntitiesPositions[entity.Key] += myEntitiesVelocities[entity.Key];
            }
        }





    }
}