Add support for reading skin frame rate from configuration file

osu.Game.Rulesets.Osu/Skinning/OsuLegacySkinTransformer.cs

@@ -46,17 +46,20 @@ namespace osu.Game.Rulesets.Osu.Skinning
             switch (osuComponent.Component)
             {
                 case OsuSkinComponents.FollowPoint:
-                    return this.GetAnimation(component.LookupName, true, false);
+                    return this.GetAnimation(component.LookupName, true, false, true);
 
                 case OsuSkinComponents.SliderFollowCircle:
-                    var followCircle = this.GetAnimation("sliderfollowcircle", true, true);
+                    var followCircle = this.GetAnimation("sliderfollowcircle", true, true, true);
                     if (followCircle != null)
                         // follow circles are 2x the hitcircle resolution in legacy skins (since they are scaled down from >1x
                         followCircle.Scale *= 0.5f;
                     return followCircle;
 
                 case OsuSkinComponents.SliderBall:
-                    var sliderBallContent = this.GetAnimation("sliderb", true, true, "");
+                    var sliderBallContent = this.GetAnimation("sliderb", true, true, animationSeparator: "");
+
+                    // todo: slider ball has a custom frame delay based on velocity
+                    // Math.Max((150 / Velocity) * GameBase.SIXTY_FRAME_TIME, GameBase.SIXTY_FRAME_TIME);
 
                     if (sliderBallContent != null)
                     {

osu.Game/Skinning/GlobalSkinConfiguration.cs

@@ -5,5 +5,6 @@ namespace osu.Game.Skinning
 {
     public enum GlobalSkinConfiguration
     {
+        AnimationFramerate
     }
 }

osu.Game/Skinning/LegacySkinExtensions.cs

@@ -1,6 +1,8 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Collections.Generic;
+using System.Linq;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Animations;
 using osu.Framework.Graphics.Sprites;
@@ -10,48 +12,62 @@ namespace osu.Game.Skinning
 {
     public static class LegacySkinExtensions
     {
-        public static Drawable GetAnimation(this ISkin source, string componentName, bool animatable, bool looping, string animationSeparator = "-")
+        public static Drawable GetAnimation(this ISkin source, string componentName, bool animatable, bool looping, bool applyConfigFrameRate = false, string animationSeparator = "-")
         {
-            const double default_frame_time = 1000 / 60d;
-
             Texture texture;
 
-            Texture getFrameTexture(int frame) => source.GetTexture($"{componentName}{animationSeparator}{frame}");
-
-            TextureAnimation animation = null;
-
             if (animatable)
             {
-                for (int i = 0; true; i++)
+                var textures = getTextures().ToArray();
+
+                if (textures.Length > 0)
                 {
-                    if ((texture = getFrameTexture(i)) == null)
+                    var animation = new TextureAnimation
-                        break;
-
-                    if (animation == null)
                     {
-                        animation = new TextureAnimation
+                        DefaultFrameLength = getFrameLength(source, applyConfigFrameRate, textures),
-                        {
+                        Repeat = looping,
-                            DefaultFrameLength = default_frame_time,
+                    };
-                            Repeat = looping
-                        };
-                    }
 
-                    animation.AddFrame(texture);
+                    foreach (var t in textures)
+                        animation.AddFrame(t);
+
+                    return animation;
                 }
             }
 
-            if (animation != null)
+            // if an animation was not allowed or not found, fall back to a sprite retrieval.
-                return animation;
-
             if ((texture = source.GetTexture(componentName)) != null)
-            {
+                return new Sprite { Texture = texture };
-                return new Sprite
-                {
-                    Texture = texture
-                };
-            }
 
             return null;
+
+            IEnumerable<Texture> getTextures()
+            {
+                for (int i = 0; true; i++)
+                {
+                    if ((texture = source.GetTexture($"{componentName}{animationSeparator}{i}")) == null)
+                        break;
+
+                    yield return texture;
+                }
+            }
+        }
+
+        private const double default_frame_time = 1000 / 60d;
+
+        private static double getFrameLength(ISkin source, bool applyConfigFrameRate, Texture[] textures)
+        {
+            if (applyConfigFrameRate)
+            {
+                var iniRate = source.GetConfig<GlobalSkinConfiguration, int>(GlobalSkinConfiguration.AnimationFramerate);
+
+                if (iniRate != null)
+                    return 1000f / iniRate.Value;
+
+                return 1000f / textures.Length;
+            }
+
+            return default_frame_time;
         }
     }
 }