Artemis/src/Artemis.Core/Plugins/LayerEffect/Abstract/BaseLayerEffect.cs

using System;
using Artemis.Core.Models.Profile;
using Artemis.Core.Plugins.Models;
using Artemis.Core.Services.Interfaces;
using SkiaSharp;

namespace Artemis.Core.Plugins.LayerEffect.Abstract
{
    /// <summary>
    ///     For internal use only, please use <see cref="LayerEffect" /> instead
    /// </summary>
    public abstract class BaseLayerEffect : IDisposable
    {
        /// <summary>
        ///     Gets the layer this effect is applied to
        /// </summary>
        public Layer Layer { get; internal set; }

        /// <summary>
        ///     Gets the folder this effect is applied to
        /// </summary>
        public Folder Folder { get; internal set; }

        /// <summary>
        ///     Gets the descriptor of this effect
        /// </summary>
        public LayerEffectDescriptor Descriptor { get; internal set; }

        /// <summary>
        ///     Gets the plugin info that defined this effect
        /// </summary>
        public PluginInfo PluginInfo => Descriptor.LayerEffectProvider.PluginInfo;

        /// <summary>
        ///     Gets a reference to the layer property group without knowing it's type
        /// </summary>
        public virtual LayerPropertyGroup BaseProperties => null;

        public void Dispose()
        {
            DisableLayerEffect();
        }

        /// <summary>
        ///     Called when the layer brush is activated
        /// </summary>
        public abstract void EnableLayerEffect();

        /// <summary>
        ///     Called when the layer brush is deactivated
        /// </summary>
        public abstract void DisableLayerEffect();

        /// <summary>
        ///     Called before rendering every frame, write your update logic here
        /// </summary>
        /// <param name="deltaTime"></param>
        public abstract void Update(double deltaTime);

        /// <summary>
        ///     Called before the layer or folder will be rendered
        /// </summary>
        public abstract void PreProcess(SKCanvas canvas, SKImageInfo canvasInfo, SKPath path, SKPaint paint);

        /// <summary>
        ///     Called after the layer of folder has been rendered
        /// </summary>
        public abstract void PostProcess(SKCanvas canvas, SKImageInfo canvasInfo, SKPath path, SKPaint paint);

        internal void InternalPreProcess(SKCanvas canvas, SKImageInfo canvasInfo, SKPath path, SKPaint paint)
        {
            // Move the canvas to the top-left of the render path
            canvas.Translate(path.Bounds.Left, path.Bounds.Top);
            // Pass the render path to the layer effect positioned at 0,0
            path.Transform(SKMatrix.MakeTranslation(path.Bounds.Left * -1, path.Bounds.Top * -1));

            PreProcess(canvas, canvasInfo, path, paint);
        }

        internal void InternalPostProcess(SKCanvas canvas, SKImageInfo canvasInfo, SKPath path, SKPaint paint)
        {
            // Move the canvas to the top-left of the render path
            canvas.Translate(path.Bounds.Left, path.Bounds.Top);
            // Pass the render path to the layer effect positioned at 0,0
            path.Transform(SKMatrix.MakeTranslation(path.Bounds.Left * -1, path.Bounds.Top * -1));

            PostProcess(canvas, canvasInfo, path, paint);
        }

        // Not only is this needed to initialize properties on the layer effects, it also prevents implementing anything
        // but LayerEffect<T> outside the core
        internal abstract void Initialize(ILayerService layerService);
    }
}