Improve ranked play rating graph's x-axis divisions

osu.Game/Screens/OnlinePlay/Matchmaking/Queue/RatingDistributionGraph.cs

@@ -24,7 +24,7 @@ namespace osu.Game.Screens.OnlinePlay.Matchmaking.Queue
     public partial class RatingDistributionGraph : CompositeDrawable, IHasCustomTooltip<RatingDistributionGraph.RatingDistributionGraphTooltipData>
     {
         private const int y_divisions = 4;
-        private const int x_divisions = 16;
+        private const int x_max_divisions = 16;
 
         [Resolved]
         private OverlayColourProvider colourProvider { get; set; } = null!;
@@ -50,6 +50,7 @@ public partial class RatingDistributionGraph : CompositeDrawable, IHasCustomTool
         private int? userRating;
         private (int min, int max, int step) xRange;
         private (int min, int max) yRange;
+        private int xDivisionStep = 1;
 
         [BackgroundDependencyLoader]
         private void load()
@@ -237,6 +238,17 @@ public void SetData((int x, int y)[] data, int? userRating)
                 data.Zip(data.Skip(1), (a, b) => Math.Abs(b.x - a.x)).DefaultIfEmpty().Min()
             );
 
+            xDivisionStep = Math.Max(xRange.step, 50); // avoid division by zero
+
+            // Keep increasing the division until number of lines is appropriately low
+            while ((xRange.max - xRange.min) / xDivisionStep > x_max_divisions)
+            {
+                xDivisionStep *= 2;
+            }
+
+            xRange.min = (int)floorWithFactor(xRange.min, xDivisionStep);
+            xRange.max = (int)ceilingWithFactor(xRange.max, xDivisionStep);
+
             if (userRating < xRange.min)
             {
                 this.data = this.data.Prepend((userRating.Value, 1)).ToArray();
@@ -249,9 +261,11 @@ public void SetData((int x, int y)[] data, int? userRating)
                 xRange.max = userRating.Value;
             }
 
+            int yMax = this.data.Select(d => d.y).DefaultIfEmpty().Max();
+
             yRange = (
                 0,
-                (int)roundToSignificant(this.data.Select(d => d.y).DefaultIfEmpty().Max())
+                (int)ceilingWithFactor(yMax, significantOfNumber(yMax))
             );
 
             updateGraph();
@@ -274,13 +288,15 @@ private void updateGraph() => Scheduler.AddOnce(() =>
             barsContainer.Clear();
             userRatingContainer.Clear();
 
-            for (int step = 0; step <= x_divisions; step++)
+            int xDivisions = Math.Max(1, (xRange.max - xRange.min) / xDivisionStep);
+
+            for (int step = 0; step <= xDivisions; step++)
             {
                 gridContainer.Add(new VerticalLine
                 {
                     RelativeSizeAxes = Axes.Y,
                     RelativePositionAxes = Axes.X,
-                    X = (float)step / x_divisions,
+                    X = (float)step / xDivisions,
                     Colour = colourProvider.Background1
                 });
 
@@ -289,10 +305,10 @@ private void updateGraph() => Scheduler.AddOnce(() =>
                     Anchor = Anchor.TopLeft,
                     Origin = Anchor.CentreRight,
                     RelativePositionAxes = Axes.X,
-                    X = (float)step / x_divisions,
+                    X = (float)step / xDivisions,
                     Margin = new MarginPadding { Right = -2 },
                     Rotation = -40,
-                    Text = (xRange.min + (xRange.max - xRange.min) / x_divisions * step).ToString(),
+                    Text = (xRange.min + xDivisionStep * step).ToString(),
                     UseFullGlyphHeight = false,
                     Font = OsuFont.Default.With(size: 12),
                     Colour = colourProvider.Foreground1
@@ -337,7 +353,7 @@ private void updateGraph() => Scheduler.AddOnce(() =>
             {
                 barsContainer.Add(new Container
                 {
-                    Origin = Anchor.BottomCentre,
+                    Origin = Anchor.BottomLeft,
                     Anchor = Anchor.BottomLeft,
                     RelativePositionAxes = Axes.X,
                     RelativeSizeAxes = Axes.Both,
@@ -393,7 +409,7 @@ private void updateGraph() => Scheduler.AddOnce(() =>
                 currentCount += d.y;
                 float p = (float)currentCount / totalCount;
                 return new Vector2(pointOnGraph(d.x, 0).X, 1 - p);
-            }).ToArray();
+            }).Append(new Vector2(1, 0)).ToArray();
         });
 
         private Vector2 pointOnGraph(int x, int y)
@@ -403,13 +419,25 @@ private Vector2 pointOnGraph(int x, int y)
             return new Vector2(xPos, yPos);
         }
 
-        private static double roundToSignificant(double value)
+        private static double significantOfNumber(double value)
+        {
+            return Math.Pow(10, Math.Floor(Math.Log10(value)));
+        }
+
+        private static double floorWithFactor(double value, double factor)
+        {
+            if (value == 0 || factor == 0)
+                return 0;
+
+            return Math.Floor(value / factor) * factor;
+        }
+
+        private static double ceilingWithFactor(double value, double factor)
         {
-            if (value == 0)
+            if (value == 0 || factor == 0)
                 return 0;
 
-            double scale = Math.Pow(10, Math.Floor(Math.Log10(value)));
-            return Math.Ceiling(value / scale) * scale;
+            return Math.Ceiling(value / factor) * factor;
         }
 
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos)
@@ -474,7 +502,7 @@ protected override bool OnMouseMove(MouseMoveEvent e)
             int currentCount = 0;
             int totalCount = data.Sum(p => p.y);
 
-            for (int i = 0; i < cumulativePath.Vertices.Count; i++)
+            for (int i = 0; i < data.Length; i++)
             {
                 currentCount += data[i].y;