osu/osu.Game/Screens/Backgrounds/BackgroundModeBeatmap.cs

//Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
//Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using osu.Framework.Allocation;
using OpenTK;
using osu.Framework.Graphics.Transformations;
using osu.Game.Beatmaps;
using osu.Game.Graphics.Background;

namespace osu.Game.Screens.Backgrounds
{
    public class BackgroundModeBeatmap : BackgroundMode
    {
        private Background background;

        private WorkingBeatmap beatmap;
        private Vector2 blurTarget;

        public WorkingBeatmap Beatmap
        {
            get
            {
                return beatmap;
            }

            set
            {
                if (beatmap == value)
                    return;

                beatmap = value;

                Schedule(() =>
                {
                    Background newBackground = new BeatmapBackground(beatmap);

                    newBackground.Preload(Game, delegate
                    {
                        Background oldBackground = background;

                        Add(background = newBackground);
                        background.BlurSigma = blurTarget;

                        if (oldBackground != null)
                        {
                            oldBackground.Depth = 1;
                            oldBackground.Flush();
                            oldBackground.FadeOut(250);
                            oldBackground.Expire();
                        }
                    });
                });
            }
        }

        public BackgroundModeBeatmap(WorkingBeatmap beatmap)
        {
            Beatmap = beatmap;
        }

        public void BlurTo(Vector2 sigma, double duration)
        {
            background?.BlurTo(sigma, duration, EasingTypes.OutExpo);
            blurTarget = sigma;
        }

        public override bool Equals(BackgroundMode other)
        {
            return base.Equals(other) && beatmap == ((BackgroundModeBeatmap)other).Beatmap;
        }

        class BeatmapBackground : Background
        {
            private WorkingBeatmap beatmap;

            public BeatmapBackground(WorkingBeatmap beatmap)
            {
                this.beatmap = beatmap;
                CacheDrawnFrameBuffer = true;
            }

            [BackgroundDependencyLoader]
            private void load()
            {
                Sprite.Texture = beatmap.Background;
            }

        }
    }
}