using AcknexWrapper;

namespace NoSchedulerTest
{
    public class Program
    {
        static void Main(string[] args)
        {
            // opening the engine
            EngFun.engine_open(null, null);

            // limit frame rate
            EngVar.fps_max = 60;

            // load an empty level
            EngFun.level_load(null);

            // create a player entity
            Player player =
                new Player(new Vector(100, 0, 0));

            // create and keep the reference to the delegate as long as it is needed !
            WrapperDelegateVoid onSpaceMethodDelegate =
                OnSpaceMethod;

            // assign the delegate to the EngVar variable
            EngVar.on_space =
                onSpaceMethodDelegate;

            // create a panel
            PANEL sliderPanel =
                PANEL.pan_create(null, 1);
            sliderPanel.SHOW = true;
            sliderPanel.size_x = 300;
            sliderPanel.size_y = 100;
            
            // allow mouse interaction
            EngVar.mouse_mode = 4;

            // create bitmaps, to be used in the slider
            BMAP sliderBackground =
                BMAP.bmap_createblack(200, 40, 24);
            BMAP sliderKnob =
                BMAP.bmap_createblack(20, 60, 24);
            sliderBackground.bmap_fill(new Color(255, 255, 255), 100);

            // the value to be read and modified by the user AND the engine
            WrappedDouble wrappedDouble =
                new WrappedDouble(50);

            // create the slider
            sliderPanel.pan_setslider(
                0,
                50,
                50,
                sliderBackground,
                sliderKnob,
                0,
                255,
                wrappedDouble);

            bool keyEnterHasBeenReleased = true;

            while (EngFun.engine_frame() != 0)
            {
                // interaction in the rendering loop
                if (EngVar.key_enter == true)
                {
                    if (keyEnterHasBeenReleased == true)
                    {
                        EngVar.sky_color.blue += 25;
                        EngVar.sky_color.blue %= 255;
                        keyEnterHasBeenReleased = false;
                    }
                }
                else
                {
                    keyEnterHasBeenReleased = true;
                }

                EngVar.sky_color.red = wrappedDouble.Value;
            }

            EngFun.engine_close();
        }

        // interaction using EngVar key events
        private static void OnSpaceMethod()
        {
            EngVar.sky_color.green += 25;
            EngVar.sky_color.green %= 255;
        }
    }

    public class Player
    {
        private readonly ENTITY PlayerEntity;

        /// <summary>
        /// the delegate has to be referenced to, as long as it is used !
        /// </summary>
        private readonly WrapperDelegateVoid PlayerRoutineDelegate;

        public Player(Vector position)
        {
            // create the entity
            this.PlayerEntity =
                ENTITY.ent_create("_CUBE.MDL", new Vector(100, 0, 0), null);

            // enable triggering of the event function, every frame !
            this.PlayerEntity.ENABLE_FRAME = true;

            // create and store the delegate
            this.PlayerRoutineDelegate =
                this.PlayerRoutine;

            // assign the event method/delegate
            this.PlayerEntity.event_ =
                this.PlayerRoutineDelegate;
        }

        // interaction using on_frame
        private void PlayerRoutine()
        {
            double speedOfPositionChange =
                2.5 * EngVar.time_step;

            if (EngVar.key_a == true)
            {
                this.PlayerEntity.y += speedOfPositionChange;
            }
            if (EngVar.key_d == true)
            {
                this.PlayerEntity.y -= speedOfPositionChange;
            }
            if (EngVar.key_w == true)
            {
                this.PlayerEntity.z += speedOfPositionChange;
            }
            if (EngVar.key_s == true)
            {
                this.PlayerEntity.z -= speedOfPositionChange;
            }
        }
    }
}