From 49497d1a78e1a5372d0298169d2e382892e894d3 Mon Sep 17 00:00:00 2001
From: Ari Vuollet <ari.vuollet@kapsi.fi>
Date: Sat, 9 Sep 2023 14:20:30 +0300
Subject: [PATCH] _font array storage

---
 Source/Engine/Render2D/Font.cpp | 44 +++++++++++++++++++++++++++++++++
 Source/Engine/Render2D/Font.h   |  6 +++++
 2 files changed, 50 insertions(+)

diff --git a/Source/Engine/Render2D/Font.cpp b/Source/Engine/Render2D/Font.cpp
index 05bf8dab0..0b584aee3 100644
--- a/Source/Engine/Render2D/Font.cpp
+++ b/Source/Engine/Render2D/Font.cpp
@@ -13,7 +13,10 @@ Font::Font(FontAsset* parentAsset, float size)
     : ManagedScriptingObject(SpawnParams(Guid::New(), Font::TypeInitializer))
     , _asset(parentAsset)
     , _size(size)
+#if USE_ARRAY_CHARACTER_STORAGE
+#else
     , _characters(512)
+#endif
 {
     _asset->_fonts.Add(this);
 
@@ -26,6 +29,12 @@ Font::Font(FontAsset* parentAsset, float size)
     _ascender = Convert26Dot6ToRoundedPixel<int16>(face->size->metrics.ascender);
     _descender = Convert26Dot6ToRoundedPixel<int16>(face->size->metrics.descender);
     _lineGap = _height - _ascender + _descender;
+#if USE_ARRAY_CHARACTER_STORAGE
+    _characters.SetCapacity(256);
+    _characters.Resize(256);
+    for (int i = 0; i < _characters.Count(); i++)
+        _characters[i].IsValid = false;
+#endif
 }
 
 Font::~Font()
@@ -36,6 +45,32 @@ Font::~Font()
 
 void Font::GetCharacter(Char c, FontCharacterEntry& result, bool enableFallback)
 {
+#if USE_ARRAY_CHARACTER_STORAGE
+    // Try to get the character or cache it if cannot be found
+    if (c >= _characters.Count())
+    {
+        // This thread race condition may happen in editor but in game we usually do all stuff with fonts on main thread (chars caching)
+        ScopeLock lock(_asset->Locker);
+
+        // Handle situation when more than one thread wants to get the same character
+        if (c >= _characters.Count())
+        {
+            int oldSize = _characters.Count();
+            int newSize = Math::Min(c + 64, 65536);
+            _characters.SetCapacity(newSize);
+            _characters.Resize(newSize);
+            for (int i = oldSize; i < newSize; i++)
+                _characters[i].IsValid = false;
+        }
+    }
+    result = _characters[c];
+    if (!result.IsValid)
+    {
+        // Create character cache
+        FontManager::AddNewEntry(this, c, _characters[c]);
+        result = _characters[c];
+    }
+#else
     // Try to get the character or cache it if cannot be found
     if (!_characters.TryGet(c, result))
     {
@@ -67,6 +102,7 @@ void Font::GetCharacter(Char c, FontCharacterEntry& result, bool enableFallback)
         // Add to the dictionary
         _characters.Add(c, result);
     }
+#endif
 }
 
 int32 Font::GetKerning(Char first, Char second) const
@@ -112,11 +148,19 @@ void Font::Invalidate()
 {
     ScopeLock lock(_asset->Locker);
 
+#if USE_ARRAY_CHARACTER_STORAGE
+    for (int32 i = 0; i < _characters.Count(); i++)
+    {
+        FontManager::Invalidate(_characters[i]);
+    }
+    _characters.Clear();
+#else
     for (auto i = _characters.Begin(); i.IsNotEnd(); ++i)
     {
         FontManager::Invalidate(i->Value);
     }
     _characters.Clear();
+#endif
 }
 
 void Font::ProcessText(const StringView& text, Array<FontLineCache>& outputLines, const TextLayoutOptions& layout, Array<FontCharacterEntry>& characterEntries, Array<float>& characterKernings)
diff --git a/Source/Engine/Render2D/Font.h b/Source/Engine/Render2D/Font.h
index e2026b6ba..79b7e7ec7 100644
--- a/Source/Engine/Render2D/Font.h
+++ b/Source/Engine/Render2D/Font.h
@@ -15,6 +15,8 @@ struct FontTextureAtlasSlot;
 // The default DPI that engine is using
 #define DefaultDPI 96
 
+#define USE_ARRAY_CHARACTER_STORAGE 1
+
 /// <summary>
 /// The text range.
 /// </summary>
@@ -239,7 +241,11 @@ private:
     int32 _descender;
     int32 _lineGap;
     bool _hasKerning;
+#if USE_ARRAY_CHARACTER_STORAGE
+    Array<FontCharacterEntry> _characters;
+#else
     Dictionary<Char, FontCharacterEntry> _characters;
+#endif
     mutable Dictionary<uint32, int32> _kerningTable;
 
 public: