osu-lazer/osu.Game/Storyboards/CommandTimelineGroup.cs

// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using OpenTK;
using OpenTK.Graphics;
using System.Collections.Generic;
using System.Linq;

namespace osu.Game.Storyboards
{
    public delegate CommandTimeline<T> CommandTimelineSelector<T>(CommandTimelineGroup commandTimelineGroup);

    public class CommandTimelineGroup
    {
        public CommandTimeline<float> X = new CommandTimeline<float>();
        public CommandTimeline<float> Y = new CommandTimeline<float>();
        public CommandTimeline<Vector2> Scale = new CommandTimeline<Vector2>();
        public CommandTimeline<float> Rotation = new CommandTimeline<float>();
        public CommandTimeline<Color4> Colour = new CommandTimeline<Color4>();
        public CommandTimeline<float> Alpha = new CommandTimeline<float>();
        public CommandTimeline<bool> Additive = new CommandTimeline<bool>();
        public CommandTimeline<bool> FlipH = new CommandTimeline<bool>();
        public CommandTimeline<bool> FlipV = new CommandTimeline<bool>();

        public IEnumerable<ICommandTimeline> Timelines
        {
            get
            {
                yield return X;
                yield return Y;
                yield return Scale;
                yield return Rotation;
                yield return Colour;
                yield return Alpha;
                yield return Additive;
                yield return FlipH;
                yield return FlipV;
            }
        }

        public double CommandsStartTime => Timelines.Where(t => t.HasCommands).Min(t => t.StartTime);
        public double CommandsEndTime => Timelines.Where(t => t.HasCommands).Max(t => t.EndTime);
        public double CommandsDuration => CommandsEndTime - CommandsStartTime;

        public virtual double StartTime => CommandsStartTime;
        public virtual double EndTime => CommandsEndTime;
        public double Duration => EndTime - StartTime;

        public bool HasCommands => Timelines.Any(t => t.HasCommands);

        public virtual IEnumerable<CommandTimeline<T>.TypedCommand> GetCommands<T>(CommandTimelineSelector<T> timelineSelector, double offset = 0)
        {
            if (offset != 0)
                return timelineSelector(this).Commands.Select(command =>
                    new CommandTimeline<T>.TypedCommand
                    {
                        Easing = command.Easing,
                        StartTime = offset + command.StartTime,
                        EndTime = offset + command.EndTime,
                        StartValue = command.StartValue,
                        EndValue = command.EndValue,
                    });

            return timelineSelector(this).Commands;
        }
    }
}