1 files changed, 71 insertions, 0 deletions
diff --git a/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Font/FontUpdateTracker.cs b/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Font/FontUpdateTracker.cs
new file mode 100644
index 0000000..a63d62b
--- /dev/null
+++ b/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Font/FontUpdateTracker.cs
@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace UnityEngine.UI
+{
+    // 全局记录使用了某个Font字体的所有Text，当这个Font的GlyphAtlas大小改变的时候通知这些Text重建mesh(更新UV）
+    // 因为GlyphAtlas大小改变了，原先的UV已经不对了
+    public static class FontUpdateTracker
+    {
+        static Dictionary<Font, HashSet<Text>> m_Tracked = new Dictionary<Font, HashSet<Text>>();
+
+        public static void TrackText(Text t)
+        {
+            if (t.font == null)
+                return;
+
+            HashSet<Text> exists;
+            m_Tracked.TryGetValue(t.font, out exists);
+            if (exists == null)
+            {
+                // font texture重新生成的时候会调这个回调，然后需要Text组件重建mesh的UV数据，因为原先的fontGlyph里的UV已经不准了
+                // https://docs.unity3d.com/ScriptReference/Font-textureRebuilt.html
+                // The textureRebuilt event is global for all fonts, so we add our delegate the first time we register *any* Text
+                if (m_Tracked.Count == 0)
+                    Font.textureRebuilt += RebuildForFont; 
+
+                exists = new HashSet<Text>();
+                m_Tracked.Add(t.font, exists);
+            }
+
+            if (!exists.Contains(t))
+                exists.Add(t);
+        }
+
+        private static void RebuildForFont(Font f)
+        {
+            HashSet<Text> texts;
+            m_Tracked.TryGetValue(f, out texts);
+
+            if (texts == null)
+                return;
+
+            foreach (var text in texts)
+                text.FontTextureChanged();
+        }
+
+        public static void UntrackText(Text t)
+        {
+            if (t.font == null)
+                return;
+
+            HashSet<Text> texts;
+            m_Tracked.TryGetValue(t.font, out texts);
+
+            if (texts == null)
+                return;
+
+            texts.Remove(t);
+
+            if (texts.Count == 0)
+            {
+                m_Tracked.Remove(t.font);
+
+                // There is a global textureRebuilt event for all fonts, so once the last Text reference goes away, remove our delegate
+                if (m_Tracked.Count == 0)
+                    Font.textureRebuilt -= RebuildForFont;
+            }
+        }
+    }
+}