Initial implementation of a test case which showcases waveforms

osu.Game/Tests/Visual/TestCaseWaveform.cs

@@ -0,0 +1,149 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Collections.Generic;
+using OpenTK;
+using OpenTK.Graphics;
+using osu.Framework.Allocation;
+using osu.Framework.Audio.Track;
+using osu.Framework.Configuration;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Game.Beatmaps;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Overlays;
+
+namespace osu.Game.Tests.Visual
+{
+    internal class TestCaseWaveform : OsuTestCase
+    {
+        private readonly Bindable<WorkingBeatmap> beatmapBacking = new Bindable<WorkingBeatmap>();
+
+        private readonly List<WaveformDisplay> displays = new List<WaveformDisplay>();
+
+        public TestCaseWaveform()
+        {
+            MusicController mc;
+            FillFlowContainer flow;
+            Child = flow = new FillFlowContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                Direction = FillDirection.Vertical,
+                Spacing = new Vector2(0, 10),
+                Children = new Drawable[]
+                {
+                    mc = new MusicController
+                    {
+                        Anchor = Anchor.TopCentre,
+                        Origin = Anchor.TopCentre,
+                        Y = 100,
+                        State = Visibility.Visible
+                    },
+                }
+            };
+
+            for (int i = 1; i <= 16; i *= 2)
+            {
+                var newDisplay = new WaveformDisplay(i) { RelativeSizeAxes = Axes.Both };
+
+                displays.Add(newDisplay);
+
+                flow.Add(new Container
+                {
+                    RelativeSizeAxes = Axes.X,
+                    Height = 100,
+                    Children = new Drawable[]
+                    {
+                        newDisplay,
+                        new Container
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            AutoSizeAxes = Axes.Both,
+                            Children = new Drawable[]
+                            {
+                                new Box
+                                {
+                                    RelativeSizeAxes = Axes.Both,
+                                    Colour = Color4.Black,
+                                    Alpha = 0.75f
+                                },
+                                new OsuSpriteText
+                                {
+                                    Anchor = Anchor.Centre,
+                                    Origin = Anchor.Centre,
+                                    Text = $"Resolution: {(1f / i).ToString("0.00")}"
+                                }
+                            }
+                        }
+                    }
+                });
+            }
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuGameBase osuGame)
+        {
+            beatmapBacking.BindTo(osuGame.Beatmap);
+            beatmapBacking.ValueChanged += b => b.Track.QueryWaveform(processWaveform);
+        }
+
+        private void processWaveform(Waveform waveform) => Schedule(() => displays.ForEach(d => d.Display(waveform)));
+
+        private class WaveformDisplay : CompositeDrawable
+        {
+            private readonly int resolution;
+
+            public WaveformDisplay(int resolution)
+            {
+                this.resolution = resolution;
+            }
+
+            public void Display(Waveform waveform)
+            {
+                ClearInternal();
+
+                var generated = waveform.Generate((int)MathHelper.Clamp(Math.Ceiling(DrawWidth), 0, waveform.TotalPoints) / resolution);
+
+                for (int i = 0; i < generated.Count; i++)
+                {
+                    var point = generated[i];
+
+                    // Left channel
+                    AddInternal(new NonInputBox
+                    {
+                        Anchor = Anchor.CentreLeft,
+                        Origin = Anchor.BottomLeft,
+                        RelativePositionAxes = Axes.X,
+                        RelativeSizeAxes = Axes.Both,
+                        X = 1f / generated.Count * i,
+                        Size = new Vector2(1f / generated.Count, point.Amplitude[0] / 2),
+                        Colour = Color4.Red
+                    });
+
+                    if (waveform.Channels >= 2)
+                    {
+                        // Right channel
+                        AddInternal(new NonInputBox
+                        {
+                            Anchor = Anchor.CentreLeft,
+                            Origin = Anchor.TopLeft,
+                            RelativePositionAxes = Axes.X,
+                            RelativeSizeAxes = Axes.Both,
+                            X = 1f / generated.Count * i,
+                            Size = new Vector2(1f / generated.Count, point.Amplitude[1] / 2),
+                            Colour = Color4.Green
+                        });
+                    }
+                }
+            }
+
+            private class NonInputBox : Box
+            {
+                public override bool HandleInput => false;
+            }
+        }
+    }
+}

osu.Game/osu.Game.csproj

@@ -777,6 +777,7 @@
     <Compile Include="Tests\Visual\TestCaseTwoLayerButton.cs" />
     <Compile Include="Tests\Visual\TestCaseUserPanel.cs" />
     <Compile Include="Tests\Visual\TestCaseUserProfile.cs" />
+    <Compile Include="Tests\Visual\TestCaseWaveform.cs" />
     <Compile Include="Users\Avatar.cs" />
     <Compile Include="Users\Country.cs" />
     <Compile Include="Users\Medal.cs" />