Add font index, support font family variants depending on language

Add `fonts/index.json` which specifies:

- List of all font files that should be loaded (filenames).
- Default font (specified by family name or by family and style name).
- Font variants for different languages, using the name of the language file as key.
- Fallback fonts.
- Icon font.

There are characters (e.g. all in `刃直海角骨入`) that look different depending on the language of the content being Japanese, Simplified Chinese, Traditional Chinese and Hangul, because Unicode uses the same codepoint for characters regardless of the language. To render these characters correctly, the active variant font is switched depending on the selected language.

The `ITextRender` interface is changed so the current language variant can be set using `SetFontLanguageVariant` and the default and icon fonts can be toggled using `SetFontPreset`.

The text render is restructured: The font faces and font atlas are now managed by a separate class `CGlyphAtlas` like on upstream.

The font files are also updated:

- Update Source Han Sans to version 2.001.
- Update Glow Sans Japanese Compressed to version 0.93.
- Update Deja Vu Sans to version 2.37.
- Update Font Awesome icons font to March 2023 version.

Closes 6881.

.gitignore

@@ -119,7 +119,6 @@ tags
 *.exe
 *.fifo
 *.filters
-*.json
 *.lnk
 *.log
 *.opensdf

CMakeLists.txt

@@ -1451,9 +1451,10 @@ set(EXPECTED_DATA
   emoticons.png
   extras.png
   fonts/DejaVuSans.ttf
-  fonts/GlowSansJCompressed-Book.otf
-  fonts/Icons.otf
-  fonts/SourceHanSansSC-Regular.otf
+  fonts/Font_Awesome_6_Free-Solid-900.otf
+  fonts/GlowSansJ-Compressed-Book.otf
+  fonts/SourceHanSans.ttc
+  fonts/index.json
   game.png
   gui_buttons.png
   gui_cursor.png
@@ -1731,7 +1732,7 @@ set(EXPECTED_DATA
   wordlist.txt
 )
 
-set_glob(DATA GLOB_RECURSE "cfg;frag;json;map;otf;png;rules;ttf;txt;vert;wv" data ${EXPECTED_DATA})
+set_glob(DATA GLOB_RECURSE "cfg;frag;json;map;otf;png;rules;ttc;ttf;txt;vert;wv" data ${EXPECTED_DATA})
 
 ########################################################################
 # COPY DATA AND SHARED LIBS

data/fonts/index.json

@@ -0,0 +1,19 @@
+{
+    "font files": [
+        "DejaVuSans.ttf",
+        "Font_Awesome_6_Free-Solid-900.otf",
+        "GlowSansJ-Compressed-Book.otf",
+        "SourceHanSans.ttc"
+    ],
+    "default": "DejaVu Sans",
+    "language variants": {
+        "japanese": "Glow Sans J Compressed Book",
+        "korean": "Source Han Sans K",
+        "simplified_chinese": "Source Han Sans SC",
+        "traditional_chinese": "Source Han Sans TC"
+    },
+    "fallbacks": [
+        "Source Han Sans"
+    ],
+    "icon": "Font Awesome 6 Free"
+}

src/engine/client.h

@@ -180,7 +180,6 @@ class IClient : public IInterface
 	virtual void SwitchWindowScreen(int Index) = 0;
 	virtual void SetWindowParams(int FullscreenMode, bool IsBorderless, bool AllowResizing) = 0;
 	virtual void ToggleWindowVSync() = 0;
-	virtual void LoadFont() = 0;
 	virtual void Notify(const char *pTitle, const char *pMessage) = 0;
 
 	virtual void UpdateAndSwap() = 0;

src/engine/client/client.cpp

@@ -3035,8 +3035,9 @@ void CClient::Run()
 	}
 #endif
 
-	// init font rendering
-	Kernel()->RequestInterface<IEngineTextRender>()->Init();
+	// init text render
+	IEngineTextRender *pTextRender = Kernel()->RequestInterface<IEngineTextRender>();
+	pTextRender->Init();
 
 	// init the input
 	Input()->Init();
@@ -3393,6 +3394,9 @@ void CClient::Run()
 		m_aNetClient[i].Close();
 
 	delete m_pEditor;
+
+	// shutdown text render while graphics are still available
+	pTextRender->Shutdown();
 }
 
 bool CClient::InitNetworkClient(char *pError, size_t ErrorSize)
@@ -4272,61 +4276,6 @@ void CClient::ToggleWindowVSync()
 		g_Config.m_GfxVsync ^= 1;
 }
 
-void CClient::LoadFont()
-{
-	static CFont *pDefaultFont = 0;
-	char aFilename[IO_MAX_PATH_LENGTH];
-	char aBuff[1024];
-	const char *pFontFile = "fonts/DejaVuSans.ttf";
-	const char *apFallbackFontFiles[] =
-		{
-			"fonts/GlowSansJCompressed-Book.otf",
-			"fonts/SourceHanSansSC-Regular.otf",
-		};
-	IOHANDLE File = Storage()->OpenFile(pFontFile, IOFLAG_READ, IStorage::TYPE_ALL, aFilename, sizeof(aFilename));
-	if(File)
-	{
-		IEngineTextRender *pTextRender = Kernel()->RequestInterface<IEngineTextRender>();
-		pDefaultFont = pTextRender->GetFont(aFilename);
-		if(pDefaultFont == NULL)
-		{
-			void *pBuf;
-			unsigned Size;
-			io_read_all(File, &pBuf, &Size);
-			pDefaultFont = pTextRender->LoadFont(aFilename, (unsigned char *)pBuf, Size);
-		}
-		io_close(File);
-
-		for(auto &pFallbackFontFile : apFallbackFontFiles)
-		{
-			bool FontLoaded = false;
-			File = Storage()->OpenFile(pFallbackFontFile, IOFLAG_READ, IStorage::TYPE_ALL, aFilename, sizeof(aFilename));
-			if(File)
-			{
-				void *pBuf;
-				unsigned Size;
-				io_read_all(File, &pBuf, &Size);
-				io_close(File);
-				FontLoaded = pTextRender->LoadFallbackFont(pDefaultFont, aFilename, (unsigned char *)pBuf, Size);
-			}
-
-			if(!FontLoaded)
-			{
-				str_format(aBuff, std::size(aBuff), "failed to load the fallback font. filename='%s'", pFallbackFontFile);
-				m_pConsole->Print(IConsole::OUTPUT_LEVEL_STANDARD, "gameclient", aBuff);
-			}
-		}
-
-		pTextRender->SetDefaultFont(pDefaultFont);
-	}
-
-	if(!pDefaultFont)
-	{
-		str_format(aBuff, std::size(aBuff), "failed to load font. filename='%s'", pFontFile);
-		m_pConsole->Print(IConsole::OUTPUT_LEVEL_STANDARD, "gameclient", aBuff);
-	}
-}
-
 void CClient::Notify(const char *pTitle, const char *pMessage)
 {
 	if(m_pGraphics->WindowActive() || !g_Config.m_ClShowNotifications)

src/engine/client/client.h

@@ -506,7 +506,6 @@ class CClient : public IClient, public CDemoPlayer::IListener
 	void SwitchWindowScreen(int Index) override;
 	void SetWindowParams(int FullscreenMode, bool IsBorderless, bool AllowResizing) override;
 	void ToggleWindowVSync() override;
-	void LoadFont() override;
 	void Notify(const char *pTitle, const char *pMessage) override;
 	void BenchmarkQuit(int Seconds, const char *pFilename);