From fa98cfa9e5e32ed52f2538ddce1179e252fcfbfc Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Fri, 16 Jun 2017 14:47:14 +0800
Subject: [PATCH] Handle max==min in LineGraph.

---
 osu.Game/Graphics/UserInterface/LineGraph.cs | 12 +++++++++---
 osu.Game/Users/Profile/RankChart.cs          | 19 ++++++++-----------
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/osu.Game/Graphics/UserInterface/LineGraph.cs b/osu.Game/Graphics/UserInterface/LineGraph.cs
index 02e8a8329a..28b62ff957 100644
--- a/osu.Game/Graphics/UserInterface/LineGraph.cs
+++ b/osu.Game/Graphics/UserInterface/LineGraph.cs
@@ -23,8 +23,8 @@ namespace osu.Game.Graphics.UserInterface
         /// </summary>
         public float? MinValue { get; set; }
 
-        public float? ActualMaxValue { get; private set; }
-        public float? ActualMinValue { get; private set; }
+        public float ActualMaxValue { get; private set; } = float.NaN;
+        public float ActualMinValue { get; private set; } = float.NaN;
 
         private const double transform_duration = 500;
 
@@ -87,10 +87,16 @@ namespace osu.Game.Graphics.UserInterface
             for (int i = 0; i < values.Length; i++)
             {
                 float x = (i + count - values.Length) / (float)(count - 1) * DrawWidth - 1;
-                float y = (max - values[i]) / (max - min) * DrawHeight - 1;
+                float y = GetYPosition(values[i]) * DrawHeight - 1;
                 // the -1 is for inner offset in path (actually -PathWidth)
                 path.AddVertex(new Vector2(x, y));
             }
         }
+
+        protected float GetYPosition(float value)
+        {
+            if (ActualMaxValue == ActualMinValue) return 0;
+            return (ActualMaxValue - value) / (ActualMaxValue - ActualMinValue);
+        }
     }
 }
diff --git a/osu.Game/Users/Profile/RankChart.cs b/osu.Game/Users/Profile/RankChart.cs
index fde7379628..8581635cd7 100644
--- a/osu.Game/Users/Profile/RankChart.cs
+++ b/osu.Game/Users/Profile/RankChart.cs
@@ -3,7 +3,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using OpenTK;
 using osu.Framework.Allocation;
@@ -93,9 +92,12 @@ namespace osu.Game.Users.Profile
         {
             graph.Colour = colours.Yellow;
 
-            // use logarithmic coordinates
-            graph.Values = ranks.Select(x => -(float)Math.Log(x));
-            graph.ResetBall();
+            if (user.Statistics.Rank > 0)
+            {
+                // use logarithmic coordinates
+                graph.Values = ranks.Select(x => -(float)Math.Log(x));
+                graph.ResetBall();
+            }
         }
 
         public override bool Invalidate(Invalidation invalidation = Invalidation.All, Drawable source = null, bool shallPropagate = true)
@@ -136,9 +138,7 @@ namespace osu.Game.Users.Profile
 
             public void ResetBall()
             {
-                Trace.Assert(ActualMaxValue.HasValue);
-                Trace.Assert(ActualMinValue.HasValue);
-                ball.MoveTo(new Vector2(1, ((ActualMaxValue - Values.Last()) / (ActualMaxValue - ActualMinValue)).Value), ballShown ? transform_duration : 0, EasingTypes.OutQuint);
+                ball.MoveTo(new Vector2(1, GetYPosition(Values.Last())), ballShown ? transform_duration : 0, EasingTypes.OutQuint);
                 ball.Show();
                 BallRelease();
                 ballShown = true;
@@ -155,10 +155,7 @@ namespace osu.Game.Users.Profile
                     if (index >= count - values.Count)
                     {
                         int i = index + values.Count - count;
-                        float value = values[i];
-                        Trace.Assert(ActualMaxValue.HasValue);
-                        Trace.Assert(ActualMinValue.HasValue);
-                        float y = ((ActualMaxValue - value) / (ActualMaxValue - ActualMinValue)).Value;
+                        float y = GetYPosition(values[i]);
                         if (Math.Abs(y * DrawHeight - position.Y) <= 8f)
                         {
                             ball.MoveTo(new Vector2(index / (float)(count - 1), y), transform_duration, EasingTypes.OutQuint);