Change: Support side-by-side fallback FontCaches instead of hierarchical.

The text layouter system can now support using different fonts for different glyphs, including mixing scalable and sprite glyphs.

src/console_cmds.cpp

@@ -2360,17 +2360,18 @@ static bool ConFont(std::span<std::string_view> argv)
 		SetFont(argfs, font, size);
 	}
 
-	for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
+	IConsolePrint(CC_INFO, "Configured fonts:");
-		FontCache *fc = FontCache::Get(fs);
+	for (uint i = 0; FontSize fs : FONTSIZES_ALL) {
-		FontCacheSubSetting *setting = GetFontCacheSubSetting(fs);
+		const FontCacheSubSetting *setting = GetFontCacheSubSetting(fs);
-		/* Make sure all non sprite fonts are loaded. */
+		IConsolePrint(CC_DEFAULT, "{}) {} font: \"{}\", size {}", i, FontSizeToName(fs), setting->font, setting->size);
-		if (!setting->font.empty() && !fc->HasParent()) {
+		++i;
-			InitFontCache(fs);
-			fc = FontCache::Get(fs);
 	}
-		IConsolePrint(CC_DEFAULT, "{} font:", FontSizeToName(fs));
+
-		IConsolePrint(CC_DEFAULT, "Currently active: \"{}\", size {}", fc->GetFontName(), fc->GetFontSize());
+	IConsolePrint(CC_INFO, "Currently active fonts:");
-		IConsolePrint(CC_DEFAULT, "Requested: \"{}\", size {}", setting->font, setting->size);
+	for (uint i = 0; const auto &fc : FontCache::Get()) {
+		if (fc == nullptr) continue;
+		IConsolePrint(CC_DEFAULT, "{}) {} font: \"{}\" size {}", i, FontSizeToName(fc->GetSize()), fc->GetFontName(), fc->GetFontSize());
+		++i;
 	}
 
 	return true;

src/fontcache.cpp

@@ -8,6 +8,8 @@
 /** @file fontcache.cpp Cache for characters from fonts. */
 
 #include "stdafx.h"
+
+#include "core/string_consumer.hpp"
 #include "fontcache.h"
 #include "blitter/factory.hpp"
 #include "gfx_layout.h"
@@ -17,13 +19,10 @@
 #include "viewport_func.h"
 #include "window_func.h"
 #include "fileio_func.h"
+#include "zoom_func.h"
 
 #include "safeguards.h"
 
-/** Default heights for the different sizes of fonts. */
-static const int _default_font_height[FS_END]   = {10, 6, 18, 10};
-static const int _default_font_ascender[FS_END] = { 8, 5, 15,  8};
-
 FontCacheSettings _fcsettings;
 
 /**
@@ -31,10 +30,10 @@ FontCacheSettings _fcsettings;
  * @param fs Font size to load.
  * @param fonttype Font type requested.
  */
-/* static */ void FontProviderManager::LoadFont(FontSize fs, FontType fonttype)
+/* static */ void FontProviderManager::LoadFont(FontSize fs, FontType fonttype, bool search, const std::string &font_name, std::span<const std::byte> os_handle)
 {
 	for (auto &provider : FontProviderManager::GetProviders()) {
-		provider->LoadFont(fs, fonttype);
+		provider->LoadFont(fs, fonttype, search, font_name, os_handle);
 	}
 }
 
@@ -47,10 +46,10 @@ FontCacheSettings _fcsettings;
  * @param callback The function to call to check for missing glyphs.
  * @return true if a font has been set, false otherwise.
  */
-/* static */ bool FontProviderManager::SetFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback)
+/* static */ bool FontProviderManager::SetFallbackFont(const std::string &language_isocode, FontSizes  bad_mask, class MissingGlyphSearcher *callback)
 {
 	for (auto &provider : FontProviderManager::GetProviders()) {
-		if (provider->SetFallbackFont(settings, language_isocode, callback)) {
+		if (provider->SetFallbackFont(language_isocode, bad_mask, callback)) {
 			return true;
 		}
 	}
@@ -61,42 +60,49 @@ FontCacheSettings _fcsettings;
  * Create a new font cache.
  * @param fs The size of the font.
  */
-FontCache::FontCache(FontSize fs) : parent(FontCache::Get(fs)), fs(fs), height(_default_font_height[fs]),
+FontCache::FontCache(FontSize fs) : fs(fs)
-		ascender(_default_font_ascender[fs]), descender(_default_font_ascender[fs] - _default_font_height[fs])
 {
-	assert(this->parent == nullptr || this->fs == this->parent->fs);
+	/* Find an empty font cache slot. */
-	FontCache::caches[this->fs] = this;
+	auto it = std::find(std::begin(FontCache::caches), std::end(FontCache::caches), nullptr);
+	if (it == std::end(FontCache::caches)) it = FontCache::caches.insert(it, nullptr);
+
+	/* Register this font cache in the slot. */
+	it->reset(this);
+
+	/* Set up our font index and make us the default font cache for this font size. */
+	this->font_index = static_cast<FontIndex>(std::distance(std::begin(FontCache::caches), it));
+	FontCache::default_font_index[fs] = this->font_index;
+
 	Layouter::ResetFontCache(this->fs);
 }
 
 /** Clean everything up. */
 FontCache::~FontCache()
 {
-	assert(this->fs == this->parent->fs);
-	FontCache::caches[this->fs] = this->parent;
 	Layouter::ResetFontCache(this->fs);
 }
 
 int FontCache::GetDefaultFontHeight(FontSize fs)
 {
-	return _default_font_height[fs];
+	return DEFAULT_FONT_HEIGHT[fs];
 }
 
-/**
+/* static */ void FontCache::UpdateCharacterHeight(FontSize fs)
- * Get the font name of a given font size.
- * @param fs The font size to look up.
- * @return The font name.
- */
-std::string FontCache::GetName(FontSize fs)
 {
-	FontCache *fc = FontCache::Get(fs);
+	FontCache::max_height[fs] = 0;
-	if (fc != nullptr) {
+	for (const auto &fc : FontCache::caches) {
-		return fc->GetFontName();
+		if (fc == nullptr || fc->fs != fs) continue;
-	} else {
+		FontCache::max_height[fs] = std::max(FontCache::max_height[fs], fc->height);
-		return "[NULL]";
 	}
+	if (FontCache::max_height[fs] == 0) FontCache::max_height[fs] = GetDefaultFontHeight(fs);
 }
 
+int FontCache::GetGlyphYOffset()
+{
+	int fs_height = FontCache::GetCharacterHeight(this->GetSize());
+	int height = this->GetAscender() - this->GetDescender();
+	return (fs_height - height) / 2;
+}
 
 /**
  * Get height of a character for a given font size.
@@ -105,16 +111,19 @@ std::string FontCache::GetName(FontSize fs)
  */
 int GetCharacterHeight(FontSize size)
 {
-	return FontCache::Get(size)->GetHeight();
+	uint height = FontCache::GetCharacterHeight(size);
+	if (height == 0) height = ScaleGUITrad(FontCache::GetDefaultFontHeight(FS_MONO));
+	return height;
 }
 
-
+/* static */ FontCache::FontCaches FontCache::caches;
-/* static */ FontCache *FontCache::caches[FS_END];
+/* static */ std::array<int, FS_END> FontCache::max_height{};
+/* static */ std::array<FontIndex, FS_END> FontCache::default_font_index{};
 
 /* static */ void FontCache::InitializeFontCaches()
 {
-	for (FontSize fs = FS_BEGIN; fs != FS_END; fs++) {
+	for (FontSize fs : FONTSIZES_ALL) {
-		if (FontCache::caches[fs] == nullptr) FontProviderManager::LoadFont(fs, FontType::Sprite); /* FontCache inserts itself into to the cache. */
+		FontCache::max_height[fs] = ScaleSpriteTrad(GetDefaultFontHeight(fs));
 	}
 }
 
@@ -145,15 +154,8 @@ void SetFont(FontSize fontsize, const std::string &font, uint size)
 	if (!changed) return;
 
 	if (fontsize != FS_MONO) {
-		/* Try to reload only the modified font. */
+		/* Check if fallback fonts are needed. */
-		FontCacheSettings backup = _fcsettings;
-		for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
-			if (fs == fontsize) continue;
-			FontCache *fc = FontCache::Get(fs);
-			GetFontCacheSubSetting(fs)->font = fc->HasParent() ? fc->GetFontName() : "";
-		}
 		CheckForMissingGlyphs();
-		_fcsettings = std::move(backup);
 	} else {
 		InitFontCache(fontsize);
 	}
@@ -171,7 +173,7 @@ void SetFont(FontSize fontsize, const std::string &font, uint size)
  */
 static bool IsDefaultFont(const FontCacheSubSetting &setting)
 {
-	return setting.font.empty() && setting.os_handle == nullptr;
+	return setting.font.empty();
 }
 
 /**
@@ -208,7 +210,7 @@ static std::string GetDefaultTruetypeFont(FontSize fs)
  * @param fs Font size.
  * @return Full path of default font file.
  */
-static std::string GetDefaultTruetypeFontFile([[maybe_unused]] FontSize fs)
+std::string GetDefaultTruetypeFontFile([[maybe_unused]] FontSize fs)
 {
 #if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
 	/* Find font file. */
@@ -237,13 +239,52 @@ std::string GetFontCacheFontName(FontSize fs)
  */
 void InitFontCache(FontSizes fontsizes)
 {
-	FontCache::InitializeFontCaches();
+	static constexpr std::string_view DEFAULT_FONT = "default";
 
 	for (FontSize fs : fontsizes) {
-		FontCache *fc = FontCache::Get(fs);
+		Layouter::ResetFontCache(fs);
-		if (fc->HasParent()) delete fc;
+		FontCache::default_font_index[fs] = INVALID_FONT_INDEX;
+	}
 
-		FontProviderManager::LoadFont(fs, FontType::TrueType);
+	/* Remove all existing FontCaches. */
+	for (auto it = std::begin(FontCache::caches); it != std::end(FontCache::caches); ++it) {
+		if (*it == nullptr) continue;
+		if (!fontsizes.Test((*it)->fs)) continue;
+		it->reset();
+	}
+
+	for (FontSize fs : fontsizes) {
+		const FontCacheSubSetting *setting = GetFontCacheSubSetting(fs);
+
+		/* Add all detected fallback fonts. */
+		for (auto &fallback : setting->fallback_fonts) {
+			FontProviderManager::LoadFont(fs, FontType::TrueType, /*fallback.dynamic ? "missing-fallback" : "language-fallback", */ false, fallback.name, fallback.os_handle);
+		}
+
+		/* Parse configured fonts, separated by ';' into a list. */
+		std::vector<std::string_view> fontnames;
+		StringConsumer consumer(setting->font);
+		do {
+			auto fontname = StrTrimView(consumer.ReadUntilChar(';', StringConsumer::SKIP_ONE_SEPARATOR), " \t");
+			if (!fontname.empty()) fontnames.push_back(fontname);
+		} while (consumer.AnyBytesLeft());
+
+		/* Add the default font as lowest priority if not manually specified. */
+		if (std::ranges::find(fontnames, DEFAULT_FONT) == std::end(fontnames)) fontnames.push_back(DEFAULT_FONT);
+
+		/* Load configured fonts in reverse order so that the first entry has priority. */
+		for (auto it = fontnames.rbegin(); it != fontnames.rend(); ++it) {
+			if (*it == DEFAULT_FONT) {
+				/* Load the sprite font, even if it's not preferred. */
+				FontProviderManager::LoadFont(fs, FontType::Sprite, /*"default"*/ false, {}, {});
+				if (!_fcsettings.prefer_sprite) {
+					/* Load the default truetype font if sprite not isn't preferred. */
+					FontProviderManager::LoadFont(fs, FontType::TrueType, /*"default",*/ false, GetDefaultTruetypeFontFile(fs), {});
+				}
+			} else {
+				FontProviderManager::LoadFont(fs, FontType::TrueType, /*"configured",*/ true, std::string{*it}, {});
+			}
+		}
 	}
 }
 
@@ -252,8 +293,5 @@ void InitFontCache(FontSizes fontsizes)
  */
 void UninitFontCache()
 {
-	for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
+	FontCache::caches.clear();
-		FontCache *fc = FontCache::Get(fs);
-		if (fc->HasParent()) delete fc;
-	}
 }

src/fontcache.h

@@ -16,17 +16,31 @@
 
 /** Glyphs are characters from a font. */
 typedef uint32_t GlyphID;
-static const GlyphID SPRITE_GLYPH = 1U << 30;
+using FontIndex = uint8_t;
+
+static const FontIndex INVALID_FONT_INDEX = std::numeric_limits<FontIndex>::max();
+
+/** Default heights for the different sizes of fonts. */
+static constexpr int DEFAULT_FONT_HEIGHT[FS_END]   = {10, 6, 18, 10};
+static constexpr int DEFAULT_FONT_ASCENDER[FS_END] = { 8, 5, 15,  8};
 
 /** Font cache for basic fonts. */
 class FontCache {
 protected:
-	static FontCache *caches[FS_END]; ///< All the font caches.
+	using FontCaches = std::vector<std::unique_ptr<FontCache>>;
-	FontCache *parent;                ///< The parent of this font cache.
+	static FontCaches caches;
+
+	static std::array<int, FS_END> max_height;
+	static std::array<FontIndex, FS_END> default_font_index;
+
 	const FontSize fs;                ///< The size of the font.
-	int height;                       ///< The height of the font.
+	FontIndex font_index; ///< The index of the font.
-	int ascender;                     ///< The ascender value of the font.
+	int height = 0; ///< The height of the font.
-	int descender;                    ///< The descender value of the font.
+	int ascender = 0; ///< The ascender value of the font.
+	int descender = 0; ///< The descender value of the font.
+
+	friend void UninitFontCache();
+	friend void InitFontCache(FontSizes fontsizes);
 
 public:
 	FontCache(FontSize fs);
@@ -42,6 +56,8 @@ public:
 	 */
 	inline FontSize GetSize() const { return this->fs; }
 
+	inline FontIndex GetIndex() const { return this->font_index; }
+
 	/**
 	 * Get the height of the font.
 	 * @return The height of the font.
@@ -92,10 +108,9 @@ public:
 	/**
 	 * Map a character into a glyph.
 	 * @param key The character.
-	 * @param fallback Allow fallback to the parent font.
 	 * @return The glyph ID used to draw the character.
 	 */
-	virtual GlyphID MapCharToGlyph(char32_t key, bool fallback = true) = 0;
+	virtual GlyphID MapCharToGlyph(char32_t key) = 0;
 
 	/**
 	 * Get the native OS font handle, if there is one.
@@ -112,25 +127,57 @@ public:
 	 */
 	virtual std::string GetFontName() = 0;
 
+	virtual int GetGlyphYOffset();
+
+	/**
+	 * Get span of all FontCaches.
+	 * @return Span of all FontCaches.
+	 */
+	static inline std::span<const std::unique_ptr<FontCache>> Get()
+	{
+		return FontCache::caches;
+	}
+
 	/**
 	 * Get the font cache of a given font size.
 	 * @param fs The font size to look up.
 	 * @return The font cache.
 	 */
-	static inline FontCache *Get(FontSize fs)
+	static inline FontCache *Get(FontIndex font_index)
 	{
-		assert(fs < FS_END);
+		assert(font_index < FontCache::caches.size());
-		return FontCache::caches[fs];
+		return FontCache::caches[font_index].get();
 	}
 
-	static std::string GetName(FontSize fs);
+	static inline int GetCharacterHeight(FontSize fs)
-
-	/**
-	 * Check whether the font cache has a parent.
-	 */
-	inline bool HasParent()
 	{
-		return this->parent != nullptr;
+		return FontCache::max_height[fs];
+	}
+
+	static void UpdateCharacterHeight(FontSize fs);
+
+	static inline FontIndex GetDefaultFontIndex(FontSize fs)
+	{
+		return FontCache::default_font_index[fs];
+	}
+
+	static inline class FontCache *GetDefaultFontCache(FontSize fs)
+	{
+		FontIndex index = FontCache::GetDefaultFontIndex(fs);
+		if (index != INVALID_FONT_INDEX) return FontCache::Get(index);
+		NOT_REACHED();
+	}
+
+	static inline FontIndex GetFontIndexForCharacter(FontSize fs, char32_t c)
+	{
+		for (auto it = std::rbegin(FontCache::caches); it != std::rend(FontCache::caches); ++it) {
+			FontCache *fc = it->get();
+			if (fc == nullptr) continue;
+			if (fc->GetSize() != fs) continue;
+			if (fc->MapCharToGlyph(c) == 0) continue;
+			return std::distance(std::begin(FontCache::caches), std::next(it).base());
+		}
+		return INVALID_FONT_INDEX;
 	}
 
 	/**
@@ -141,36 +188,55 @@ public:
 
 inline void ClearFontCache(FontSizes fontsizes)
 {
-	for (FontSize fs : fontsizes) {
+	for (const auto &fc : FontCache::Get()) {
-		FontCache::Get(fs)->ClearFontCache();
+		if (fc == nullptr) continue;
+		if (!fontsizes.Test(fc->GetSize())) continue;
+		fc->ClearFontCache();
 	}
 }
 
 /** Get the Sprite for a glyph */
 inline const Sprite *GetGlyph(FontSize size, char32_t key)
 {
-	FontCache *fc = FontCache::Get(size);
+	FontIndex font_index = FontCache::GetFontIndexForCharacter(size, key);
+	FontCache *fc = font_index != INVALID_FONT_INDEX ? FontCache::Get(font_index) : FontCache::GetDefaultFontCache(size);
+	if (fc == nullptr) return nullptr;
 	return fc->GetGlyph(fc->MapCharToGlyph(key));
 }
 
 /** Get the width of a glyph */
 inline uint GetGlyphWidth(FontSize size, char32_t key)
 {
-	FontCache *fc = FontCache::Get(size);
+	FontIndex font_index = FontCache::GetFontIndexForCharacter(size, key);
+	FontCache *fc = font_index != INVALID_FONT_INDEX ? FontCache::Get(font_index) : FontCache::GetDefaultFontCache(size);
+	if (fc == nullptr) return 0;
 	return fc->GetGlyphWidth(fc->MapCharToGlyph(key));
 }
 
-inline bool GetDrawGlyphShadow(FontSize size)
-{
-	return FontCache::Get(size)->GetDrawGlyphShadow();
-}
-
 /** Settings for a single font. */
 struct FontCacheSubSetting {
 	std::string font; ///< The name of the font, or path to the font.
 	uint size;        ///< The (requested) size of the font.
 
-	const void *os_handle = nullptr; ///< Optional native OS font info. Only valid during font search.
+	struct FontCacheFallback {
+		std::string name;
+		std::vector<std::byte> os_handle;
+		bool dynamic;
+	};
+
+	std::vector<FontCacheFallback> fallback_fonts;
+
+	/**
+	 * Add a fallback font this font size configuration.
+	 * @param name Name of font to add.
+	 * @param handle OS-specific handle or data of font.
+	 */
+	template <typename T>
+	void AddFallback(const std::string &name, T &handle)
+	{
+		auto os_data = std::as_bytes(std::span(&handle, 1));
+		this->fallback_fonts.emplace_back(name, std::vector<std::byte>{os_data.begin(), os_data.end()});
+	}
 };
 
 /** Settings for the four different fonts. */
@@ -228,14 +294,14 @@ public:
 		ProviderManager<FontCacheFactory>::Unregister(*this);
 	}
 
-	virtual void LoadFont(FontSize fs, FontType fonttype) = 0;
+	virtual void LoadFont(FontSize fs, FontType fonttype, bool search, const std::string &font_name, std::span<const std::byte> os_handle) = 0;
-	virtual bool SetFallbackFont(struct FontCacheSettings *settings, const std::string &language_isocode, class MissingGlyphSearcher *callback) = 0;
+	virtual bool SetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, class MissingGlyphSearcher *callback) = 0;
 };
 
 class FontProviderManager : ProviderManager<FontCacheFactory> {
 public:
-	static void LoadFont(FontSize fs, FontType fonttype);
+	static void LoadFont(FontSize fs, FontType fonttype, bool search, const std::string &font_name, std::span<const std::byte> os_handle);
-	static bool SetFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback);
+	static bool SetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, class MissingGlyphSearcher *callback);
 };
 
 /* Implemented in spritefontcache.cpp */

src/fontcache/freetypefontcache.cpp

@@ -40,7 +40,7 @@ public:
 	FreeTypeFontCache(FontSize fs, FT_Face face, int pixels);
 	~FreeTypeFontCache();
 	void ClearFontCache() override;
-	GlyphID MapCharToGlyph(char32_t key, bool allow_fallback = true) override;
+	GlyphID MapCharToGlyph(char32_t key) override;
 	std::string GetFontName() override { return fmt::format("{}, {}", face->family_name, face->style_name); }
 	bool IsBuiltInFont() override { return false; }
 	const void *GetOSHandle() override { return &face; }
@@ -104,6 +104,7 @@ void FreeTypeFontCache::SetFontSize(int pixels)
 		this->ascender     = this->face->size->metrics.ascender >> 6;
 		this->descender    = this->face->size->metrics.descender >> 6;
 		this->height       = this->ascender - this->descender;
+		FontCache::UpdateCharacterHeight(this->fs);
 	} else {
 		/* Both FT_Set_Pixel_Sizes and FT_Select_Size failed. */
 		Debug(fontcache, 0, "Font size selection failed. Using FontCache defaults.");
@@ -193,17 +194,11 @@ const Sprite *FreeTypeFontCache::InternalGetGlyph(GlyphID key, bool aa)
 }
 
 
-GlyphID FreeTypeFontCache::MapCharToGlyph(char32_t key, bool allow_fallback)
+GlyphID FreeTypeFontCache::MapCharToGlyph(char32_t key)
 {
 	assert(IsPrintable(key));
 
-	FT_UInt glyph = FT_Get_Char_Index(this->face, key);
+	return FT_Get_Char_Index(this->face, key);
-
-	if (glyph == 0 && allow_fallback && key >= SCC_SPRITE_START && key <= SCC_SPRITE_END) {
-		return this->parent->MapCharToGlyph(key);
-	}
-
-	return glyph;
 }
 
 FT_Library _ft_library = nullptr;
@@ -225,15 +220,10 @@ public:
 	 * format is 'font family name' or 'font family name, font style'.
 	 * @param fs The font size to load.
 	 */
-	void LoadFont(FontSize fs, FontType fonttype) override
+	void LoadFont(FontSize fs, FontType fonttype, bool search, const std::string &font, std::span<const std::byte> os_handle) override
 	{
 		if (fonttype != FontType::TrueType) return;
 
-		FontCacheSubSetting *settings = GetFontCacheSubSetting(fs);
-
-		std::string font = GetFontCacheFontName(fs);
-		if (font.empty()) return;
-
 		if (_ft_library == nullptr) {
 			if (FT_Init_FreeType(&_ft_library) != FT_Err_Ok) {
 				ShowInfo("Unable to initialize FreeType, using sprite fonts instead");
@@ -247,7 +237,9 @@ public:
 
 		/* If font is an absolute path to a ttf, try loading that first. */
 		int32_t index = 0;
-		if (settings->os_handle != nullptr) index = *static_cast<const int32_t *>(settings->os_handle);
+		if (os_handle.size() == sizeof(index)) {
+			index = *reinterpret_cast<const int32_t *>(os_handle.data());
+		}
 		FT_Error error = FT_New_Face(_ft_library, font.c_str(), index, &face);
 
 		if (error != FT_Err_Ok) {
@@ -259,24 +251,24 @@ public:
 		}
 
 #ifdef WITH_FONTCONFIG
-		/* Try loading based on font face name (OS-wide fonts). */
+		/* If allowed to search, try loading based on font face name (OS-wide fonts). */
-		if (error != FT_Err_Ok) error = GetFontByFaceName(font, &face);
+		if (error != FT_Err_Ok && search) error = GetFontByFaceName(font, &face);
 #endif /* WITH_FONTCONFIG */
 
 		if (error == FT_Err_Ok) {
 			error = LoadFont(fs, face, font, GetFontCacheFontSize(fs));
 			if (error != FT_Err_Ok) {
-				ShowInfo("Unable to use '{}' for {} font, FreeType reported error 0x{:X}, using sprite font instead", font, FontSizeToName(fs), error);
+				ShowInfo("Unable to use '{}' for {} font, FreeType reported error 0x{:X}", font, FontSizeToName(fs), error);
 			}
 		} else {
 			FT_Done_Face(face);
 		}
 	}
 
-	bool SetFallbackFont(struct FontCacheSettings *settings, const std::string &language_isocode, class MissingGlyphSearcher *callback) override
+	bool SetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, MissingGlyphSearcher *callback) override
 	{
 #ifdef WITH_FONTCONFIG
-		if (FontConfigSetFallbackFont(settings, language_isocode, callback)) return true;
+		if (FontConfigSetFallbackFont(language_isocode, bad_mask, callback)) return true;
 #endif /* WITH_FONTCONFIG */
 
 		return false;

src/fontcache/spritefontcache.cpp

@@ -38,8 +38,15 @@ static int ScaleFontTrad(int value)
  */
 SpriteFontCache::SpriteFontCache(FontSize fs) : FontCache(fs)
 {
-	this->height = ScaleGUITrad(FontCache::GetDefaultFontHeight(this->fs));
+	this->UpdateMetrics();
-	this->ascender = (this->height - ScaleFontTrad(FontCache::GetDefaultFontHeight(this->fs))) / 2;
+}
+
+void SpriteFontCache::UpdateMetrics()
+{
+	this->height = ScaleGUITrad(DEFAULT_FONT_HEIGHT[this->fs]);
+	this->ascender = ScaleFontTrad(DEFAULT_FONT_ASCENDER[fs]);
+	this->descender = ScaleFontTrad(DEFAULT_FONT_ASCENDER[fs] - DEFAULT_FONT_HEIGHT[fs]);
+	FontCache::UpdateCharacterHeight(this->fs);
 }
 
 /**
@@ -60,30 +67,29 @@ SpriteID SpriteFontCache::GetSpriteIDForChar(char32_t key)
 void SpriteFontCache::ClearFontCache()
 {
 	Layouter::ResetFontCache(this->fs);
-	this->height = ScaleGUITrad(FontCache::GetDefaultFontHeight(this->fs));
+	this->UpdateMetrics();
-	this->ascender = (this->height - ScaleFontTrad(FontCache::GetDefaultFontHeight(this->fs))) / 2;
 }
 
 const Sprite *SpriteFontCache::GetGlyph(GlyphID key)
 {
-	SpriteID sprite = this->GetSpriteIDForChar(static_cast<char32_t>(key & ~SPRITE_GLYPH));
+	SpriteID sprite = this->GetSpriteIDForChar(static_cast<char32_t>(key));
 	if (sprite == 0) sprite = this->GetSpriteIDForChar('?');
 	return GetSprite(sprite, SpriteType::Font);
 }
 
 uint SpriteFontCache::GetGlyphWidth(GlyphID key)
 {
-	SpriteID sprite = this->GetSpriteIDForChar(static_cast<char32_t>(key & ~SPRITE_GLYPH));
+	SpriteID sprite = this->GetSpriteIDForChar(static_cast<char32_t>(key));
 	if (sprite == 0) sprite = this->GetSpriteIDForChar('?');
 	return SpriteExists(sprite) ? GetSprite(sprite, SpriteType::Font)->width + ScaleFontTrad(this->fs != FS_NORMAL ? 1 : 0) : 0;
 }
 
-GlyphID SpriteFontCache::MapCharToGlyph(char32_t key, [[maybe_unused]] bool allow_fallback)
+GlyphID SpriteFontCache::MapCharToGlyph(char32_t key)
 {
 	assert(IsPrintable(key));
 	SpriteID sprite = this->GetSpriteIDForChar(key);
 	if (sprite == 0) return 0;
-	return SPRITE_GLYPH | key;
+	return static_cast<GlyphID>(key);
 }
 
 bool SpriteFontCache::GetDrawGlyphShadow()
@@ -95,14 +101,14 @@ class SpriteFontCacheFactory : public FontCacheFactory {
 public:
 	SpriteFontCacheFactory() : FontCacheFactory("sprite", "Sprite font provider") {}
 
-	void LoadFont(FontSize fs, FontType fonttype) override
+	void LoadFont(FontSize fs, FontType fonttype, bool, const std::string &, std::span<const std::byte>) override
 	{
 		if (fonttype != FontType::Sprite) return;
 
 		new SpriteFontCache(fs);
 	}
 
-	bool SetFallbackFont(struct FontCacheSettings *, const std::string &, class MissingGlyphSearcher *) override
+	bool SetFallbackFont(const std::string &, FontSizes, class MissingGlyphSearcher *) override
 	{
 		return false;
 	}

src/fontcache/spritefontcache.h

@@ -21,11 +21,12 @@ public:
 	const Sprite *GetGlyph(GlyphID key) override;
 	uint GetGlyphWidth(GlyphID key) override;
 	bool GetDrawGlyphShadow() override;
-	GlyphID MapCharToGlyph(char32_t key, bool allow_fallback = true) override;
+	GlyphID MapCharToGlyph(char32_t key) override;
 	std::string GetFontName() override { return "sprite"; }
 	bool IsBuiltInFont() override { return true; }
 
 private:
+	void UpdateMetrics();
 	SpriteID GetSpriteIDForChar(char32_t key);
 };
 

src/fontcache/truetypefontcache.cpp

@@ -64,8 +64,6 @@ bool TrueTypeFontCache::GetDrawGlyphShadow()
 
 uint TrueTypeFontCache::GetGlyphWidth(GlyphID key)
 {
-	if ((key & SPRITE_GLYPH) != 0) return this->parent->GetGlyphWidth(key);
-
 	GlyphEntry *glyph = this->GetGlyphPtr(key);
 	if (glyph == nullptr || glyph->data == nullptr) {
 		this->GetGlyph(key);
@@ -77,8 +75,6 @@ uint TrueTypeFontCache::GetGlyphWidth(GlyphID key)
 
 const Sprite *TrueTypeFontCache::GetGlyph(GlyphID key)
 {
-	if ((key & SPRITE_GLYPH) != 0) return this->parent->GetGlyph(key);
-
 	/* Check for the glyph in our cache */
 	GlyphEntry *glyph = this->GetGlyphPtr(key);
 	if (glyph != nullptr && glyph->data != nullptr) return glyph->GetSprite();

src/gfx.cpp

@@ -481,6 +481,12 @@ static void SetColourRemap(TextColour colour)
 	_colour_remap_ptr = _string_colourremap;
 }
 
+static void RenderGlyph(FontCache *fc, GlyphID glyph, int left, int, int top, int)
+{
+	const Sprite *sprite = fc->GetGlyph(glyph);
+	GfxMainBlitter(sprite, left, top, BlitterMode::ColourRemap);
+};
+
 /**
  * Drawing routine for drawing a laid out line of text.
  * @param line      String to draw.
@@ -595,6 +601,9 @@ static int DrawLayoutLine(const ParagraphLayouter::Line &line, int y, int left,
 			colour_has_shadow = (colour & TC_NO_SHADE) == 0 && colour != TC_BLACK;
 			SetColourRemap(do_shadow ? TC_BLACK : colour); // the last run also sets the colour for the truncation dots
 			if (do_shadow && (!fc->GetDrawGlyphShadow() || !colour_has_shadow)) continue;
+			int height = GetCharacterHeight(fc->GetSize());
+
+			auto render = RenderGlyph;
 
 			DrawPixelInfo *dpi = _cur_dpi;
 			int dpi_left  = dpi->left;
@@ -612,14 +621,16 @@ static int DrawLayoutLine(const ParagraphLayouter::Line &line, int y, int left,
 
 				/* Truncated away. */
 				if (truncation && (begin_x < min_x || end_x > max_x)) continue;
+				/* Outside the clipping area. */
+				if (begin_x > dpi_right || end_x < dpi_left) continue;
 
-				const Sprite *sprite = fc->GetGlyph(glyph);
+				if (do_shadow) {
-				/* Check clipping (the "+ 1" is for the shadow). */
+					begin_x += shadow_offset;
-				if (begin_x + sprite->x_offs > dpi_right || begin_x + sprite->x_offs + sprite->width /* - 1 + 1 */ < dpi_left) continue;
+					end_x += shadow_offset;
+					top += shadow_offset;
+				}
 
-				if (do_shadow && (glyph & SPRITE_GLYPH) != 0) continue;
+				render(fc, glyph, begin_x, end_x, top, top + height - 1);
-
-				GfxMainBlitter(sprite, begin_x + (do_shadow ? shadow_offset : 0), top + (do_shadow ? shadow_offset : 0), BlitterMode::ColourRemap);
 			}
 		}
 

src/gfx_layout.cpp

@@ -38,18 +38,17 @@
 std::unique_ptr<Layouter::LineCache> Layouter::linecache;
 
 /** Cache of Font instances. */
-Layouter::FontColourMap Layouter::fonts[FS_END];
+std::unordered_map<FontIndex, Layouter::FontColourMap> Layouter::fonts;
 
 
 /**
  * Construct a new font.
- * @param size   The font size to use for this font.
+ * @param font_index The font index to use for this font.
  * @param colour The colour to draw this font in.
  */
-Font::Font(FontSize size, TextColour colour) :
+Font::Font(FontIndex font_index, TextColour colour) :
-		fc(FontCache::Get(size)), colour(colour)
+		fc(FontCache::Get(font_index)), colour(colour)
 {
-	assert(size < FS_END);
 }
 
 /**
@@ -71,7 +70,7 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view s
 	const typename T::CharType *buffer_last = buff_begin + str.size() + 1;
 	typename T::CharType *buff = buff_begin;
 	FontMap &font_mapping = line.runs;
-	Font *f = Layouter::GetFont(state.fontsize, state.cur_colour);
+	Font *f = Layouter::GetFont(state.font_index, state.cur_colour);
 
 	font_mapping.clear();
 
@@ -80,7 +79,10 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view s
 	 * whenever the font changes, and convert the wide characters into a format
 	 * usable by ParagraphLayout.
 	 */
-	for (char32_t c : Utf8View(str)) {
+	Utf8View view(str);
+	for (auto it = view.begin(); it != view.end(); /* nothing */) {
+		auto cur = it;
+		uint32_t c = *it++;
 		if (c == '\0' || c == '\n') {
 			/* Caller should already have filtered out these characters. */
 			NOT_REACHED();
@@ -95,19 +97,40 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view s
 		} else {
 			/* Filter out non printable characters */
 			if (!IsPrintable(c)) continue;
+
+			if (IsTextDirectionChar(c)) {
 				/* Filter out text direction characters that shouldn't be drawn, and
 				 * will not be handled in the fallback case because they are mostly
 				 * needed for RTL languages which need more proper shaping support. */
-			if (!T::SUPPORTS_RTL && IsTextDirectionChar(c)) continue;
+				if constexpr (!T::SUPPORTS_RTL) continue;
+
 				buff += T::AppendToBuffer(buff, buffer_last, c);
 				if (buff >= buffer_last) break;
 				continue;
 			}
 
-		if (font_mapping.empty() || font_mapping.back().first != buff - buff_begin) {
+			FontIndex font_index = FontCache::GetFontIndexForCharacter(state.fontsize, c);
+
+			if (font_index == INVALID_FONT_INDEX) {
+				font_index = FontCache::GetDefaultFontIndex(state.fontsize);
+			}
+
+			if (state.font_index == font_index) {
+				buff += T::AppendToBuffer(buff, buffer_last, c);
+				if (buff >= buffer_last) break;
+				continue;
+			}
+
+			/* This character goes in the next run so don't advance. */
+			state.font_index = font_index;
+
+			it = cur;
+		}
+
+		if (buff - buff_begin > 0 && (font_mapping.empty() || font_mapping.back().first != buff - buff_begin)) {
 			font_mapping.emplace_back(buff - buff_begin, f);
 		}
-		f = Layouter::GetFont(state.fontsize, state.cur_colour);
+		f = Layouter::GetFont(state.font_index, state.cur_colour);
 	}
 
 	/* Better safe than sorry. */
@@ -116,6 +139,14 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view s
 	if (font_mapping.empty() || font_mapping.back().first != buff - buff_begin) {
 		font_mapping.emplace_back(buff - buff_begin, f);
 	}
+
+	if constexpr (!std::is_same_v<T, FallbackParagraphLayoutFactory>) {
+		/* Don't layout if all runs use a built-in font and we're not using the fallback layouter. */
+		if (std::all_of(std::begin(font_mapping), std::end(font_mapping), [](const auto &i) { return i.second->fc->IsBuiltInFont(); })) {
+			return;
+		}
+	}
+
 	line.layout = T::GetParagraphLayout(buff_begin, buff, font_mapping);
 	line.state_after = state;
 }
@@ -128,7 +159,7 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view s
  */
 Layouter::Layouter(std::string_view str, int maxw, FontSize fontsize) : string(str)
 {
-	FontState state(TC_INVALID, fontsize);
+	FontState state(TC_INVALID, fontsize, FontCache::GetDefaultFontIndex(fontsize));
 
 	while (true) {
 		auto line_length = str.find_first_of('\n');
@@ -341,13 +372,17 @@ ptrdiff_t Layouter::GetCharAtPosition(int x, size_t line_index) const
 /**
  * Get a static font instance.
  */
-Font *Layouter::GetFont(FontSize size, TextColour colour)
+Font *Layouter::GetFont(FontIndex font_index, TextColour colour)
 {
-	FontColourMap::iterator it = fonts[size].find(colour);
+	if (font_index == INVALID_FONT_INDEX) return nullptr;
-	if (it != fonts[size].end()) return it->second.get();
+	assert(font_index < FontCache::Get().size());
 
-	fonts[size][colour] = std::make_unique<Font>(size, colour);
+	FontColourMap &fcm = Layouter::fonts[font_index];
-	return fonts[size][colour].get();
+	auto it = fcm.find(colour);
+	if (it != fcm.end()) return it->second.get();
+
+	fcm[colour] = std::make_unique<Font>(font_index, colour);
+	return fcm[colour].get();
 }
 
 /**
@@ -362,11 +397,10 @@ void Layouter::Initialize()
 
 /**
  * Reset cached font information.
- * @param size Font size to reset.
  */
-void Layouter::ResetFontCache(FontSize size)
+void Layouter::ResetFontCache([[maybe_unused]] FontSize size)
 {
-	fonts[size].clear();
+	Layouter::fonts.clear();
 
 	/* We must reset the linecache since it references the just freed fonts */
 	ResetLineCache();

src/gfx_layout.h

@@ -23,11 +23,12 @@
  */
 struct FontState {
 	FontSize fontsize; ///< Current font size.
+	FontIndex font_index; ///< Current font index.
 	TextColour cur_colour; ///< Current text colour.
 	std::vector<TextColour> colour_stack; ///< Stack of colours to assist with colour switching.
 
-	FontState() : fontsize(FS_END), cur_colour(TC_INVALID) {}
+	FontState() : fontsize(FS_END), font_index(INVALID_FONT_INDEX), cur_colour(TC_INVALID) {}
-	FontState(TextColour colour, FontSize fontsize) : fontsize(fontsize), cur_colour(colour) {}
+	FontState(TextColour colour, FontSize fontsize, FontIndex font_index) : fontsize(fontsize), font_index(font_index), cur_colour(colour) {}
 
 	auto operator<=>(const FontState &) const = default;
 
@@ -67,6 +68,7 @@ struct FontState {
 	inline void SetFontSize(FontSize f)
 	{
 		this->fontsize = f;
+		this->font_index = FontCache::GetDefaultFontIndex(this->fontsize);
 	}
 };
 
@@ -85,9 +87,10 @@ template <> struct std::hash<FontState> {
 	std::size_t operator()(const FontState &state) const noexcept
 	{
 		size_t h1 = std::hash<FontSize>{}(state.fontsize);
-		size_t h2 = std::hash<TextColour>{}(state.cur_colour);
+		size_t h2 = std::hash<FontIndex>{}(state.font_index);
-		size_t h3 = std::hash<std::vector<TextColour>>{}(state.colour_stack);
+		size_t h3 = std::hash<TextColour>{}(state.cur_colour);
-		return h1 ^ (h2 << 1) ^ (h3 << 2);
+		size_t h4 = std::hash<std::vector<TextColour>>{}(state.colour_stack);
+		return h1 ^ (h2 << 1) ^ (h3 << 2) ^ (h4 << 3);
 	}
 };
 
@@ -99,7 +102,7 @@ public:
 	FontCache *fc;     ///< The font we are using.
 	TextColour colour; ///< The colour this font has to be.
 
-	Font(FontSize size, TextColour colour);
+	Font(FontIndex font_index, TextColour colour);
 };
 
 /** Mapping from index to font. The pointer is owned by FontColourMap. */
@@ -206,9 +209,9 @@ private:
 	static LineCacheItem &GetCachedParagraphLayout(std::string_view str, const FontState &state);
 
 	using FontColourMap = std::map<TextColour, std::unique_ptr<Font>>;
-	static FontColourMap fonts[FS_END];
+	static std::unordered_map<FontIndex, FontColourMap> fonts;
 public:
-	static Font *GetFont(FontSize size, TextColour colour);
+	static Font *GetFont(FontIndex font_index, TextColour colour);
 
 	Layouter(std::string_view str, int maxw = INT32_MAX, FontSize fontsize = FS_NORMAL);
 	Dimension GetBounds();
@@ -216,7 +219,7 @@ public:
 	ptrdiff_t GetCharAtPosition(int x, size_t line_index) const;
 
 	static void Initialize();
-	static void ResetFontCache(FontSize size);
+	static void ResetFontCache(FontSize fs);
 	static void ResetLineCache();
 };
 

src/gfx_layout_fallback.cpp

@@ -51,7 +51,7 @@ public:
 		int GetGlyphCount() const override { return static_cast<int>(this->glyphs.size()); }
 		std::span<const GlyphID> GetGlyphs() const override { return this->glyphs; }
 		std::span<const Position> GetPositions() const override { return this->positions; }
-		int GetLeading() const override { return this->GetFont()->fc->GetHeight(); }
+		int GetLeading() const override { return GetCharacterHeight(this->GetFont()->fc->GetSize()); }
 		std::span<const int> GetGlyphToCharMap() const override { return this->glyph_to_char; }
 	};
 
@@ -112,23 +112,17 @@ public:
 FallbackParagraphLayout::FallbackVisualRun::FallbackVisualRun(Font *font, const char32_t *chars, int char_count, int char_offset, int x) :
 		font(font)
 {
-	const bool isbuiltin = font->fc->IsBuiltInFont();
-
 	this->glyphs.reserve(char_count);
 	this->glyph_to_char.reserve(char_count);
 	this->positions.reserve(char_count);
 
+	FontCache &fc = *this->font->fc;
+	int y_offset = fc.GetGlyphYOffset();;
 	int advance = x;
 	for (int i = 0; i < char_count; i++) {
-		const GlyphID &glyph_id = this->glyphs.emplace_back(font->fc->MapCharToGlyph(chars[i]));
+		const GlyphID &glyph_id = this->glyphs.emplace_back(fc.MapCharToGlyph(chars[i]));
-		int x_advance = font->fc->GetGlyphWidth(glyph_id);
+		int x_advance = fc.GetGlyphWidth(glyph_id);
-		if (isbuiltin) {
+		this->positions.emplace_back(advance, advance + x_advance - 1, y_offset); // No ascender adjustment.
-			this->positions.emplace_back(advance, advance + x_advance - 1, font->fc->GetAscender()); // Apply sprite font's ascender.
-		} else if (chars[i] >= SCC_SPRITE_START && chars[i] <= SCC_SPRITE_END) {
-			this->positions.emplace_back(advance, advance + x_advance - 1, (font->fc->GetHeight() - ScaleSpriteTrad(FontCache::GetDefaultFontHeight(font->fc->GetSize()))) / 2); // Align sprite font to centre
-		} else {
-			this->positions.emplace_back(advance, advance + x_advance - 1, 0); // No ascender adjustment.
-		}
 		advance += x_advance;
 		this->glyph_to_char.push_back(char_offset + i);
 	}
@@ -234,6 +228,7 @@ std::unique_ptr<const ParagraphLayouter::Line> FallbackParagraphLayout::NextLine
 	}
 
 	const FontCache *fc = iter->second->fc;
+	assert(fc != nullptr);
 	const char32_t *next_run = this->buffer_begin + iter->first;
 
 	const char32_t *begin = this->buffer;
@@ -251,6 +246,7 @@ std::unique_ptr<const ParagraphLayouter::Line> FallbackParagraphLayout::NextLine
 
 		if (this->buffer == next_run) {
 			int w = l->GetWidth();
+			assert(iter->second->fc != nullptr);
 			l->emplace_back(iter->second, begin, this->buffer - begin, begin - this->buffer_begin, w);
 			++iter;
 			assert(iter != this->runs.end());

src/gfx_layout_fallback.h

@@ -26,5 +26,24 @@ public:
 	static size_t AppendToBuffer(char32_t *buff, const char32_t *buffer_last, char32_t c);
 };
 
+/**
+ * Swap paired brackets for fallback RTL layouting.
+ * @param c Character to swap.
+ * @return Swapped character, or original character if it is not a paired bracket.
+ */
+inline char32_t SwapRtlPairedCharacters(char32_t c)
+{
+	/* There are many more paired brackets, but for fallback purposes we only handle ASCII brackets. */
+	/* https://www.unicode.org/Public/UCD/latest/ucd/BidiBrackets.txt */
+	switch (c) {
+		case U'(': return U')';
+		case U')': return U'(';
+		case U'[': return U']';
+		case U']': return U'[';
+		case U'{': return U'}';
+		case U'}': return U'{';
+		default: return c;
+	}
+}
 
 #endif /* GFX_LAYOUT_FALLBACK_H */

src/gfx_layout_icu.cpp

@@ -9,8 +9,10 @@
 
 #include "stdafx.h"
 #include "gfx_layout_icu.h"
+#include "gfx_layout_fallback.h"
 
 #include "debug.h"
+#include "string_func.h"
 #include "strings_func.h"
 #include "language.h"
 #include "table/control_codes.h"
@@ -51,6 +53,7 @@ public:
 	ICURun(int start, int length, UBiDiLevel level, UScriptCode script = USCRIPT_UNKNOWN, Font *font = nullptr) : start(start), length(length), level(level), script(script), font(font) {}
 
 	void Shape(UChar *buff, size_t length);
+	void FallbackShape(UChar *buff);
 };
 
 /**
@@ -76,7 +79,7 @@ public:
 		std::span<const int> GetGlyphToCharMap() const override { return this->glyph_to_char; }
 
 		const Font *GetFont() const override { return this->font; }
-		int GetLeading() const override { return this->font->fc->GetHeight(); }
+		int GetLeading() const override { return GetCharacterHeight(this->font->fc->GetSize()); }
 		int GetGlyphCount() const override { return this->glyphs.size(); }
 		int GetAdvance() const { return this->total_advance; }
 	};
@@ -135,12 +138,52 @@ ICUParagraphLayout::ICUVisualRun::ICUVisualRun(const ICURun &run, int x) :
 	assert(!run.positions.empty());
 	this->positions.reserve(run.positions.size());
 
+	int y_offset = this->font->fc->GetGlyphYOffset();
 	/* Copy positions, moving x coordinate by x offset. */
 	for (const auto &pos : run.positions) {
-		this->positions.emplace_back(pos.left + x, pos.right + x, pos.top);
+		this->positions.emplace_back(pos.left + x, pos.right + x, pos.top + y_offset);
 	}
 }
 
+/**
+ * Manually shape a run for built-in non-truetype fonts.
+ * Similar to but not quite the same as \a UniscribeRun::FallbackShape.
+ * @param buff The complete buffer of the run.
+ */
+void ICURun::FallbackShape(UChar *buff)
+{
+	this->glyphs.reserve(this->length);
+	this->glyph_to_char.reserve(this->length);
+
+	/* Read each UTF-16 character, mapping to an appropriate glyph. */
+	for (int i = this->start; i < this->start + this->length; ++i) {
+		char32_t c = Utf16DecodeChar(buff + i);
+		if (this->level & 1) c = SwapRtlPairedCharacters(c);
+		this->glyphs.emplace_back(this->font->fc->MapCharToGlyph(c));
+		this->glyph_to_char.push_back(i);
+		if (Utf16IsLeadSurrogate(*(buff + i))) ++i;
+	}
+
+	/* Reverse the sequence if this run is RTL. */
+	if (this->level & 1) {
+		std::reverse(std::begin(this->glyphs), std::end(this->glyphs));
+		std::reverse(std::begin(this->glyph_to_char), std::end(this->glyph_to_char));
+	}
+
+	this->positions.reserve(this->glyphs.size());
+
+	/* Set positions of each glyph. */
+	int y_offset = (GetCharacterHeight(this->font->fc->GetSize()) - this->font->fc->GetHeight()) / 2;
+	int advance = 0;
+	for (const GlyphID glyph : this->glyphs) {
+		int x_advance = this->font->fc->GetGlyphWidth(glyph);
+		this->positions.emplace_back(advance, advance + x_advance - 1, y_offset);
+		this->advance.push_back(x_advance);
+		advance += x_advance;
+	}
+	this->total_advance = advance;
+}
+
 /**
  * Shape a single run.
  *
@@ -149,6 +192,17 @@ ICUParagraphLayout::ICUVisualRun::ICUVisualRun(const ICURun &run, int x) :
  */
 void ICURun::Shape(UChar *buff, size_t buff_length)
 {
+	/* Make sure any former run is lost. */
+	this->glyphs.clear();
+	this->glyph_to_char.clear();
+	this->positions.clear();
+	this->advance.clear();
+
+	if (this->font->fc->IsBuiltInFont()) {
+		this->FallbackShape(buff);
+		return;
+	}
+
 	auto hbfont = hb_ft_font_create_referenced(*(static_cast<const FT_Face *>(font->fc->GetOSHandle())));
 	/* Match the flags with how we render the glyphs. */
 	hb_ft_font_set_load_flags(hbfont, GetFontAAState() ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO);
@@ -170,12 +224,6 @@ void ICURun::Shape(UChar *buff, size_t buff_length)
 	auto glyph_info = hb_buffer_get_glyph_infos(hbbuf, &glyph_count);
 	auto glyph_pos = hb_buffer_get_glyph_positions(hbbuf, &glyph_count);
 
-	/* Make sure any former run is lost. */
-	this->glyphs.clear();
-	this->glyph_to_char.clear();
-	this->positions.clear();
-	this->advance.clear();
-
 	/* Reserve space, as we already know the size. */
 	this->glyphs.reserve(glyph_count);
 	this->glyph_to_char.reserve(glyph_count);
@@ -183,20 +231,12 @@ void ICURun::Shape(UChar *buff, size_t buff_length)
 	this->advance.reserve(glyph_count);
 
 	/* Prepare the glyphs/position. ICUVisualRun will give the position an offset if needed. */
+	int y_offset = (GetCharacterHeight(this->font->fc->GetSize()) - this->font->fc->GetHeight()) / 2;
 	hb_position_t advance = 0;
 	for (unsigned int i = 0; i < glyph_count; i++) {
-		int x_advance;
+		int x_advance = glyph_pos[i].x_advance / FONT_SCALE;
-
-		if (buff[glyph_info[i].cluster] >= SCC_SPRITE_START && buff[glyph_info[i].cluster] <= SCC_SPRITE_END && glyph_info[i].codepoint == 0) {
-			auto glyph = this->font->fc->MapCharToGlyph(buff[glyph_info[i].cluster]);
-			x_advance = this->font->fc->GetGlyphWidth(glyph);
-			this->glyphs.push_back(glyph);
-			this->positions.emplace_back(advance, advance + x_advance - 1, (this->font->fc->GetHeight() - ScaleSpriteTrad(FontCache::GetDefaultFontHeight(this->font->fc->GetSize()))) / 2); // Align sprite font to centre
-		} else {
-			x_advance = glyph_pos[i].x_advance / FONT_SCALE;
 		this->glyphs.push_back(glyph_info[i].codepoint);
-			this->positions.emplace_back(glyph_pos[i].x_offset / FONT_SCALE + advance, glyph_pos[i].x_offset / FONT_SCALE + advance + x_advance - 1, glyph_pos[i].y_offset / FONT_SCALE);
+		this->positions.emplace_back(glyph_pos[i].x_offset / FONT_SCALE + advance, glyph_pos[i].x_offset / FONT_SCALE + advance + x_advance - 1, glyph_pos[i].y_offset / FONT_SCALE + y_offset);
-		}
 
 		this->glyph_to_char.push_back(glyph_info[i].cluster);
 		this->advance.push_back(x_advance);
@@ -359,11 +399,6 @@ std::vector<ICURun> ItemizeStyle(std::vector<ICURun> &runs_current, FontMap &fon
 	/* Can't layout an empty string. */
 	if (length == 0) return nullptr;
 
-	/* Can't layout our in-built sprite fonts. */
-	for (auto const &[position, font] : font_mapping) {
-		if (font->fc->IsBuiltInFont()) return nullptr;
-	}
-
 	auto runs = ItemizeBidi(buff, length);
 	runs = ItemizeScript(buff, length, runs);
 	runs = ItemizeStyle(runs, font_mapping);

src/os/macosx/font_osx.cpp

@@ -26,6 +26,7 @@
 CoreTextFontCache::CoreTextFontCache(FontSize fs, CFAutoRelease<CTFontDescriptorRef> &&font, int pixels) : TrueTypeFontCache(fs, pixels), font_desc(std::move(font))
 {
 	this->SetFontSize(pixels);
+	FontCache::UpdateCharacterHeight(this->fs);
 }
 
 /**
@@ -94,7 +95,7 @@ void CoreTextFontCache::SetFontSize(int pixels)
 	Debug(fontcache, 2, "Loaded font '{}' with size {}", this->font_name, pixels);
 }
 
-GlyphID CoreTextFontCache::MapCharToGlyph(char32_t key, bool allow_fallback)
+GlyphID CoreTextFontCache::MapCharToGlyph(char32_t key)
 {
 	assert(IsPrintable(key));
 
@@ -112,10 +113,6 @@ GlyphID CoreTextFontCache::MapCharToGlyph(char32_t key, bool allow_fallback)
 		return glyph[0];
 	}
 
-	if (allow_fallback && key >= SCC_SPRITE_START && key <= SCC_SPRITE_END) {
-		return this->parent->MapCharToGlyph(key);
-	}
-
 	return 0;
 }
 
@@ -211,7 +208,7 @@ public:
 	 * fallback search, use it. Otherwise, try to resolve it by font name.
 	 * @param fs The font size to load.
 	 */
-	void LoadFont(FontSize fs, FontType fonttype)
+	void LoadFont(FontSize fs, FontType fonttype, bool search, const std::string &font, std::span<const std::byte> os_handle) override
 	{
 		if (fonttype != FontType::TrueType) return;
 
@@ -259,7 +256,7 @@ public:
 		new CoreTextFontCache(fs, std::move(font_ref), GetFontCacheFontSize(fs));
 	}
 
-	bool SetFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback) override
+	bool SetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, MissingGlyphSearcher *callback)
 	{
 		/* Determine fallback font using CoreText. This uses the language isocode
 		 * to find a suitable font. CoreText is available from 10.5 onwards. */
@@ -305,7 +302,7 @@ public:
 				/* Skip bold fonts (especially Arial Bold, which looks worse than regular Arial). */
 				if (symbolic_traits & kCTFontBoldTrait) continue;
 				/* Select monospaced fonts if asked for. */
-				if (((symbolic_traits & kCTFontMonoSpaceTrait) == kCTFontMonoSpaceTrait) != callback->Monospace()) continue;
+				if (((symbolic_traits & kCTFontMonoSpaceTrait) == kCTFontMonoSpaceTrait) != fontsizes.Test(FS_MONO)) continue;
 
 				/* Get font name. */
 				char buffer[128];
@@ -323,7 +320,13 @@ public:
 				if (name.starts_with(".") || name.starts_with("LastResort")) continue;
 
 				/* Save result. */
-				callback->SetFontNames(settings, name);
+				for (FontSize fs : bad_mask) {
+					GetFontCacheSubSetting(fs)->AddFallback(name, std::nullopt);
+				}
+
+				// InitFontCache(bad_mask);
+				// return true;
+
 				if (!callback->FindMissingGlyphs()) {
 					Debug(fontcache, 2, "CT-Font for {}: {}", language_isocode, name);
 					result = true;
@@ -335,7 +338,9 @@ public:
 		if (!result) {
 			/* For some OS versions, the font 'Arial Unicode MS' does not report all languages it
 			 * supports. If we didn't find any other font, just try it, maybe we get lucky. */
-			callback->SetFontNames(settings, "Arial Unicode MS");
+			for (FontSize fs : bad_mask) {
+				GetFontCacheSubSetting(fs)->AddFallback("Arial Unicode MS", std::nullopt);
+			}
 			result = !callback->FindMissingGlyphs();
 		}
 

src/os/macosx/font_osx.h

@@ -28,7 +28,7 @@ public:
 	~CoreTextFontCache() {}
 
 	void ClearFontCache() override;
-	GlyphID MapCharToGlyph(char32_t key, bool allow_fallback = true) override;
+	GlyphID MapCharToGlyph(char32_t key) override;
 	std::string GetFontName() override { return font_name; }
 	bool IsBuiltInFont() override { return false; }
 	const void *GetOSHandle() override { return font.get(); }

src/os/macosx/string_osx.cpp

@@ -52,7 +52,7 @@ extern "C" {
 /** Cached current locale. */
 static CFAutoRelease<CFLocaleRef> _osx_locale;
 /** CoreText cache for font information, cleared when OTTD changes fonts. */
-static CFAutoRelease<CTFontRef> _font_cache[FS_END];
+static std::unordered_map<FontIndex, CFAutoRelease<CTFontRef>> _font_cache;
 
 
 /**
@@ -88,7 +88,7 @@ public:
 		std::span<const int> GetGlyphToCharMap() const override { return this->glyph_to_char; }
 
 		const Font *GetFont() const override { return this->font;  }
-		int GetLeading() const override { return this->font->fc->GetHeight(); }
+		int GetLeading() const override { return GetCharacterHeight(this->font->fc->GetSize()); }
 		int GetGlyphCount() const override { return (int)this->glyphs.size(); }
 		int GetAdvance() const { return this->total_advance; }
 	};
@@ -137,17 +137,17 @@ public:
 
 
 /** Get the width of an encoded sprite font character.  */
-static CGFloat SpriteFontGetWidth(void *ref_con)
+static CGFloat CustomFontGetWidth(void *ref_con)
 {
-	FontSize fs = (FontSize)((size_t)ref_con >> 24);
+	FontIndex fi = static_cast<FontIndex>(reinterpret_cast<uintptr_t>(ref_con) >> 24);
-	char32_t c = (char32_t)((size_t)ref_con & 0xFFFFFF);
+	char32_t c = static_cast<char32_t>(reinterpret_cast<uintptr_t>(ref_con) & 0xFFFFFF);
 
-	return GetGlyphWidth(fs, c);
+	return FontCache::Get(fi)->GetGlyphWidth(c);
 }
 
 static const CTRunDelegateCallbacks _sprite_font_callback = {
 	kCTRunDelegateCurrentVersion, nullptr, nullptr, nullptr,
-	&SpriteFontGetWidth
+	&CustomFontGetWidth
 };
 
 /* static */ std::unique_ptr<ParagraphLayouter> CoreTextParagraphLayoutFactory::GetParagraphLayout(CharType *buff, CharType *buff_end, FontMap &font_mapping)
@@ -158,11 +158,6 @@ static const CTRunDelegateCallbacks _sprite_font_callback = {
 	ptrdiff_t length = buff_end - buff;
 	if (length == 0) return nullptr;
 
-	/* Can't layout our in-built sprite fonts. */
-	for (const auto &[position, font] : font_mapping) {
-		if (font->fc->IsBuiltInFont()) return nullptr;
-	}
-
 	/* Make attributed string with embedded font information. */
 	CFAutoRelease<CFMutableAttributedStringRef> str(CFAttributedStringCreateMutable(kCFAllocatorDefault, 0));
 	CFAttributedStringBeginEditing(str.get());
@@ -181,12 +176,12 @@ static const CTRunDelegateCallbacks _sprite_font_callback = {
 
 		CTFontRef font_handle = static_cast<CTFontRef>(font->fc->GetOSHandle());
 		if (font_handle == nullptr) {
-			if (!_font_cache[font->fc->GetSize()]) {
+			if (!_font_cache[font->fc->GetIndex()]) {
 				/* Cache font information. */
 				CFAutoRelease<CFStringRef> font_name(CFStringCreateWithCString(kCFAllocatorDefault, font->fc->GetFontName().c_str(), kCFStringEncodingUTF8));
-				_font_cache[font->fc->GetSize()].reset(CTFontCreateWithName(font_name.get(), font->fc->GetFontSize(), nullptr));
+				_font_cache[font->fc->GetIndex()].reset(CTFontCreateWithName(font_name.get(), font->fc->GetFontSize(), nullptr));
 			}
-			font_handle = _font_cache[font->fc->GetSize()].get();
+			font_handle = _font_cache[font->fc->GetIndex()].get();
 		}
 		CFAttributedStringSetAttribute(str.get(), CFRangeMake(last, position - last), kCTFontAttributeName, font_handle);
 
@@ -194,10 +189,10 @@ static const CTRunDelegateCallbacks _sprite_font_callback = {
 		CFAttributedStringSetAttribute(str.get(), CFRangeMake(last, position - last), kCTForegroundColorAttributeName, color);
 		CGColorRelease(color);
 
-		/* Install a size callback for our special private-use sprite glyphs in case the font does not provide them. */
+		/* Install a size callback for our custom fonts. */
-		for (ssize_t c = last; c < position; c++) {
+		if (font->fc->IsBuiltInFont()) {
-			if (buff[c] >= SCC_SPRITE_START && buff[c] <= SCC_SPRITE_END && font->fc->MapCharToGlyph(buff[c], false) == 0) {
+			for (ssize_t c = last; c < i.first; c++) {
-				CFAutoRelease<CTRunDelegateRef> del(CTRunDelegateCreate(&_sprite_font_callback, (void *)(size_t)(buff[c] | (font->fc->GetSize() << 24))));
+				CFAutoRelease<CTRunDelegateRef> del(CTRunDelegateCreate(&_custom_font_callback, static_cast<void *>(reinterpret_cast<uintptr_t>(buff[c] | (font->fc->GetIndex() << 24)))));
 				/* According to the official documentation, if a run delegate is used, the char should always be 0xFFFC. */
 				CFAttributedStringReplaceString(str.get(), CFRangeMake(c, 1), replacment_str.get());
 				CFAttributedStringSetAttribute(str.get(), CFRangeMake(c, 1), kCTRunDelegateAttributeName, del.get());
@@ -247,19 +242,15 @@ CoreTextParagraphLayout::CoreTextVisualRun::CoreTextVisualRun(CTRunRef run, Font
 	CTRunGetAdvances(run, CFRangeMake(0, 0), advs);
 	this->positions.reserve(this->glyphs.size());
 
+	int y_offset = this->font->fc->GetGlyphYOffset();
+
 	/* Convert glyph array to our data type. At the same time, substitute
 	 * the proper glyphs for our private sprite glyphs. */
 	CGGlyph gl[this->glyphs.size()];
 	CTRunGetGlyphs(run, CFRangeMake(0, 0), gl);
 	for (size_t i = 0; i < this->glyphs.size(); i++) {
-		if (buff[this->glyph_to_char[i]] >= SCC_SPRITE_START && buff[this->glyph_to_char[i]] <= SCC_SPRITE_END && (gl[i] == 0 || gl[i] == 3)) {
-			/* A glyph of 0 indidicates not found, while apparently 3 is what char 0xFFFC maps to. */
-			this->glyphs[i] = font->fc->MapCharToGlyph(buff[this->glyph_to_char[i]]);
-			this->positions.emplace_back(pts[i].x, pts[i].x + advs[i].width - 1, (font->fc->GetHeight() - ScaleSpriteTrad(FontCache::GetDefaultFontHeight(font->fc->GetSize()))) / 2); // Align sprite font to centre
-		} else {
 		this->glyphs[i] = gl[i];
-			this->positions.emplace_back(pts[i].x, pts[i].x + advs[i].width - 1, pts[i].y);
+		this->positions.emplace_back(pts[i].x, pts[i].x + advs[i].width - 1, pts[i].y + y_offset);
-		}
 	}
 	this->total_advance = (int)std::ceil(CTRunGetTypographicBounds(run, CFRangeMake(0, 0), nullptr, nullptr, nullptr));
 }

src/os/unix/font_unix.cpp

@@ -120,10 +120,14 @@ FT_Error GetFontByFaceName(std::string_view font_name, FT_Face *face)
 		}
 	}
 
+	if (err != FT_Err_Ok) {
+		ShowInfo("Unable to find '{}' font", font_name);
+	}
+
 	return err;
 }
 
-bool FontConfigSetFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback)
+bool FontConfigSetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, MissingGlyphSearcher *callback)
 {
 	bool ret = false;
 
@@ -132,22 +136,25 @@ bool FontConfigSetFallbackFont(FontCacheSettings *settings, const std::string &l
 	auto fc_instance = AutoRelease<FcConfig, FcConfigDestroy>(FcConfigReference(nullptr));
 	assert(fc_instance != nullptr);
 
+	/* Get set of required characters. XXX Do we know what font size we want here? */
+	auto chars = callback->GetRequiredGlyphs(bad_mask);
+
 	/* Fontconfig doesn't handle full language isocodes, only the part
 	 * before the _ of e.g. en_GB is used, so "remove" everything after
 	 * the _. */
-	std::string lang = fmt::format(":lang={}", language_isocode.substr(0, language_isocode.find('_')));
+	std::string lang = language_isocode.empty() ? "" : fmt::format(":lang={}", language_isocode.substr(0, language_isocode.find('_')));
 
 	/* First create a pattern to match the wanted language. */
 	auto pat = AutoRelease<FcPattern, FcPatternDestroy>(FcNameParse(ToFcString(lang)));
 	/* We only want to know these attributes. */
-	auto os = AutoRelease<FcObjectSet, FcObjectSetDestroy>(FcObjectSetBuild(FC_FILE, FC_INDEX, FC_SPACING, FC_SLANT, FC_WEIGHT, nullptr));
+	auto os = AutoRelease<FcObjectSet, FcObjectSetDestroy>(FcObjectSetBuild(FC_FILE, FC_INDEX, FC_SPACING, FC_SLANT, FC_WEIGHT, FC_CHARSET, nullptr));
 	/* Get the list of filenames matching the wanted language. */
 	auto fs = AutoRelease<FcFontSet, FcFontSetDestroy>(FcFontList(nullptr, pat.get(), os.get()));
 
 	if (fs == nullptr) return ret;
 
 	int best_weight = -1;
-	const char *best_font = nullptr;
+	std::string best_font;
 	int best_index = 0;
 
 	for (FcPattern *font : std::span(fs->fonts, fs->nfont)) {
@@ -158,7 +165,7 @@ bool FontConfigSetFallbackFont(FontCacheSettings *settings, const std::string &l
 		/* Get a font with the right spacing .*/
 		int value = 0;
 		FcPatternGetInteger(font, FC_SPACING, 0, &value);
-		if (callback->Monospace() != (value == FC_MONO) && value != FC_DUAL) continue;
+		if (bad_mask.Test(FS_MONO) != (value == FC_MONO) && value != FC_DUAL) continue;
 
 		/* Do not use those that explicitly say they're slanted. */
 		FcPatternGetInteger(font, FC_SLANT, 0, &value);
@@ -168,26 +175,35 @@ bool FontConfigSetFallbackFont(FontCacheSettings *settings, const std::string &l
 		FcPatternGetInteger(font, FC_WEIGHT, 0, &value);
 		if (value <= best_weight) continue;
 
+		size_t matching_chars = 0;
+		FcCharSet *charset;
+		FcPatternGetCharSet(font, FC_CHARSET, 0, &charset);
+		for (const char32_t &c : chars) {
+			if (FcCharSetHasChar(charset, c)) ++matching_chars;
+		}
+
+		if (matching_chars < chars.size()) {
+			// Debug(fontcache, 0, "Font \"{}\" misses {} glyphs", (char *)file, chars.size() - matching_chars);
+			continue;
+		}
+
 		/* Possible match based on attributes, get index. */
 		int32_t index;
 		res = FcPatternGetInteger(font, FC_INDEX, 0, &index);
 		if (res != FcResultMatch) continue;
 
-		callback->SetFontNames(settings, FromFcString(file), &index);
-
-		bool missing = callback->FindMissingGlyphs();
-		Debug(fontcache, 1, "Font \"{}\" misses{} glyphs", FromFcString(file), missing ? "" : " no");
-
-		if (!missing) {
 		best_weight = value;
 		best_font = FromFcString(file);
 		best_index = index;
 	}
+
+	if (best_font.empty()) return false;
+
+	for (FontSize fs : bad_mask) {
+		GetFontCacheSubSetting(fs)->AddFallback(best_font, best_index);
 	}
 
-	if (best_font == nullptr) return false;
+	InitFontCache(bad_mask);
 
-	callback->SetFontNames(settings, best_font, &best_index);
-	InitFontCache(callback->Monospace() ? FontSizes{FS_MONO} : FONTSIZES_REQUIRED);
 	return true;
 }

src/os/unix/font_unix.h

@@ -19,7 +19,7 @@
 
 FT_Error GetFontByFaceName(std::string_view font_name, FT_Face *face);
 
-bool FontConfigSetFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback);
+bool FontConfigSetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, MissingGlyphSearcher *callback);
 
 #endif /* WITH_FONTCONFIG */
 

src/os/windows/font_win32.cpp

@@ -31,8 +31,8 @@
 #include "../../safeguards.h"
 
 struct EFCParam {
-	FontCacheSettings *settings;
 	LOCALESIGNATURE locale;
+	FontSizes fontsizes;
 	MissingGlyphSearcher *callback;
 	std::vector<std::wstring> fonts;
 
@@ -59,7 +59,7 @@ static int CALLBACK EnumFontCallback(const ENUMLOGFONTEX *logfont, const NEWTEXT
 	/* Don't use SYMBOL fonts */
 	if (logfont->elfLogFont.lfCharSet == SYMBOL_CHARSET) return 1;
 	/* Use monospaced fonts when asked for it. */
-	if (info->callback->Monospace() && (logfont->elfLogFont.lfPitchAndFamily & (FF_MODERN | FIXED_PITCH)) != (FF_MODERN | FIXED_PITCH)) return 1;
+	if (info->fontsizes.Test(FS_MONO) && (logfont->elfLogFont.lfPitchAndFamily & (FF_MODERN | FIXED_PITCH)) != (FF_MODERN | FIXED_PITCH)) return 1;
 
 	/* The font has to have at least one of the supported locales to be usable. */
 	auto check_bitfields = [&]() {
@@ -78,8 +78,15 @@ static int CALLBACK EnumFontCallback(const ENUMLOGFONTEX *logfont, const NEWTEXT
 	char font_name[MAX_PATH];
 	convert_from_fs(logfont->elfFullName, font_name);
 
-	info->callback->SetFontNames(info->settings, font_name, &logfont->elfLogFont);
+	Debug(misc, 0, "Trying font {}", font_name);
-	if (info->callback->FindMissingGlyphs()) return 1;
+	for (FontSize fs : info->fontsizes) {
+		GetFontCacheSubSetting(fs)->AddFallback(font_name, logfont->elfLogFont);
+	}
+
+	InitFontCache(info->fontsizes);
+	if (info->callback->FindMissingGlyphs().None()) {
+		return 1;
+	}
 	Debug(fontcache, 1, "Fallback font: {}", font_name);
 	return 0; // stop enumerating
 }
@@ -156,10 +163,11 @@ void Win32FontCache::SetFontSize(int pixels)
 	this->height = this->ascender + this->descender;
 	this->glyph_size.cx = otm->otmTextMetrics.tmMaxCharWidth;
 	this->glyph_size.cy = otm->otmTextMetrics.tmHeight;
+	FontCache::UpdateCharacterHeight(this->fs);
 
 	this->fontname = FS2OTTD((LPWSTR)((BYTE *)otm + (ptrdiff_t)otm->otmpFaceName));
 
-	Debug(fontcache, 2, "Loaded font '{}' with size {}", this->fontname, pixels);
+	Debug(fontcache, 2, "Win32FontCache: Loaded font '{}' with size {}", this->fontname, pixels);
 	delete[] (BYTE*)otm;
 }
 
@@ -246,7 +254,7 @@ void Win32FontCache::ClearFontCache()
 	return this->SetGlyphPtr(key, std::move(new_glyph)).GetSprite();
 }
 
-/* virtual */ GlyphID Win32FontCache::MapCharToGlyph(char32_t key, bool allow_fallback)
+/* virtual */ GlyphID Win32FontCache::MapCharToGlyph(char32_t key)
 {
 	assert(IsPrintable(key));
 
@@ -263,7 +271,7 @@ void Win32FontCache::ClearFontCache()
 	GetGlyphIndicesW(this->dc, chars, key >= 0x010000U ? 2 : 1, glyphs, GGI_MARK_NONEXISTING_GLYPHS);
 
 	if (glyphs[0] != 0xFFFF) return glyphs[0];
-	return allow_fallback && key >= SCC_SPRITE_START && key <= SCC_SPRITE_END ? this->parent->MapCharToGlyph(key) : 0;
+	return 0;
 }
 
 class Win32FontCacheFactory : FontCacheFactory {
@@ -276,27 +284,23 @@ public:
 	 * fallback search, use it. Otherwise, try to resolve it by font name.
 	 * @param fs The font size to load.
 	 */
-	void LoadFont(FontSize fs, FontType fonttype) override
+	void LoadFont(FontSize fs, FontType fonttype, bool search, const std::string &font, std::span<const std::byte> os_handle) override
 	{
 		if (fonttype != FontType::TrueType) return;
 
-		FontCacheSubSetting *settings = GetFontCacheSubSetting(fs);
-
-		std::string font = GetFontCacheFontName(fs);
-		if (font.empty()) return;
-
 		LOGFONT logfont{};
 		logfont.lfPitchAndFamily = fs == FS_MONO ? FIXED_PITCH : VARIABLE_PITCH;
 		logfont.lfCharSet = DEFAULT_CHARSET;
 		logfont.lfOutPrecision = OUT_OUTLINE_PRECIS;
 		logfont.lfClipPrecision = CLIP_DEFAULT_PRECIS;
 
-		if (settings->os_handle != nullptr) {
+		if (!os_handle.empty()) {
-			logfont = *(const LOGFONT *)settings->os_handle;
+			logfont = *reinterpret_cast<const LOGFONT *>(os_handle.data());
 		} else if (font.find('.') != std::string::npos) {
 			/* Might be a font file name, try load it. */
 			if (!TryLoadFontFromFile(font, logfont)) {
 				ShowInfo("Unable to load file '{}' for {} font, using default windows font selection instead", font, FontSizeToName(fs));
+				if (!search) return;
 			}
 		}
 
@@ -308,7 +312,7 @@ public:
 		LoadWin32Font(fs, logfont, GetFontCacheFontSize(fs), font);
 	}
 
-	bool SetFallbackFont(FontCacheSettings *settings, const std::string &language_isocode, MissingGlyphSearcher *callback) override
+	bool SetFallbackFont(const std::string &language_isocode, FontSizes bad_mask, MissingGlyphSearcher *callback) override
 	{
 		Debug(fontcache, 1, "Trying fallback fonts");
 		EFCParam langInfo;
@@ -318,7 +322,7 @@ public:
 			Debug(fontcache, 1, "Can't get locale info for fallback font (isocode={})", language_isocode);
 			return false;
 		}
-		langInfo.settings = settings;
+		langInfo.fontsizes = bad_mask;
 		langInfo.callback = callback;
 
 		LOGFONT font;

src/os/windows/font_win32.h

@@ -37,11 +37,11 @@ public:
 	Win32FontCache(FontSize fs, const LOGFONT &logfont, int pixels);
 	~Win32FontCache();
 	void ClearFontCache() override;
-	GlyphID MapCharToGlyph(char32_t key, bool allow_fallback = true) override;
+	GlyphID MapCharToGlyph(char32_t key) override;
 	std::string GetFontName() override { return this->fontname; }
 	const void *GetOSHandle() override { return &this->logfont; }
 };
 
-void LoadWin32Font(FontSize fs);
+void LoadWin32Font(FontSize fs, bool search, const std::string &font_name, std::span<const std::byte> os_handle);
 
 #endif /* FONT_WIN32_H */

src/os/windows/string_uniscribe.cpp

@@ -10,6 +10,7 @@
 #include "../../stdafx.h"
 #include "../../debug.h"
 #include "string_uniscribe.h"
+#include "../../gfx_layout_fallback.h"
 #include "../../language.h"
 #include "../../strings_func.h"
 #include "../../string_func.h"
@@ -29,7 +30,7 @@
 
 
 /** Uniscribe cache for internal font information, cleared when OTTD changes fonts. */
-static SCRIPT_CACHE _script_cache[FS_END];
+static std::map<FontIndex, SCRIPT_CACHE> _script_cache;
 
 /**
  * Contains all information about a run of characters. A run are consecutive
@@ -52,6 +53,8 @@ struct UniscribeRun {
 	int total_advance;
 
 	UniscribeRun(int pos, int len, Font *font, SCRIPT_ANALYSIS &sa) : pos(pos), len(len), font(font), sa(sa) {}
+
+	void FallbackShape(const UniscribeParagraphLayoutFactory::CharType *buff);
 };
 
 /** Break a string into language formatting ranges. */
@@ -94,7 +97,7 @@ public:
 		std::span<const int> GetGlyphToCharMap() const override;
 
 		const Font *GetFont() const override { return this->font;  }
-		int GetLeading() const override { return this->font->fc->GetHeight(); }
+		int GetLeading() const override { return GetCharacterHeight(this->font->fc->GetSize()); }
 		int GetGlyphCount() const override { return this->num_glyphs; }
 		int GetAdvance() const { return this->total_advance; }
 	};
@@ -130,12 +133,12 @@ public:
 	std::unique_ptr<const Line> NextLine(int max_width) override;
 };
 
-void UniscribeResetScriptCache(FontSize size)
+void UniscribeResetScriptCache(FontSize)
 {
-	if (_script_cache[size] != nullptr) {
+	for (auto &sc : _script_cache) {
-		ScriptFreeCache(&_script_cache[size]);
+		ScriptFreeCache(&sc.second);
-		_script_cache[size] = nullptr;
 	}
+	_script_cache.clear();
 }
 
 /** Load the matching native Windows font. */
@@ -152,6 +155,41 @@ static HFONT HFontFromFont(Font *font)
 	return CreateFontIndirect(&logfont);
 }
 
+/**
+ * Manually shape a run for built-in non-truetype fonts.
+ * Similar to but not quite the same as \a ICURun::FallbackShape.
+ * @param buff The complete buffer of the run.
+ */
+void UniscribeRun::FallbackShape(const UniscribeParagraphLayoutFactory::CharType *buff)
+{
+	this->glyphs.reserve(this->len);
+
+	/* Read each UTF-16 character, mapping to an appropriate glyph. */
+	for (int i = this->pos; i < this->pos + this->len; ++i) {
+		char32_t c = Utf16DecodeChar(reinterpret_cast<const char16_t *>(buff + i));
+		if (this->sa.fRTL) c = SwapRtlPairedCharacters(c);
+		this->glyphs.emplace_back(this->font->fc->MapCharToGlyph(c));
+		if (Utf16IsLeadSurrogate(*(buff + i))) ++i;
+	}
+
+	/* Reverse the sequence if this run is RTL. */
+	if (this->sa.fRTL) {
+		std::reverse(std::begin(this->glyphs), std::end(this->glyphs));
+	}
+
+	this->offsets.reserve(this->glyphs.size());
+
+	/* Set positions of each glyph. */
+	int y_offset = this->font->fc->GetGlyphYOffset();
+	int advance = 0;
+	for (const GlyphID glyph : this->glyphs) {
+		this->offsets.emplace_back(advance, y_offset);
+		int x_advance = this->font->fc->GetGlyphWidth(glyph);
+		this->advances.push_back(x_advance);
+		advance += x_advance;
+	}
+}
+
 /** Determine the glyph positions for a run. */
 static bool UniscribeShapeRun(const UniscribeParagraphLayoutFactory::CharType *buff, UniscribeRun &range)
 {
@@ -166,10 +204,15 @@ static bool UniscribeShapeRun(const UniscribeParagraphLayoutFactory::CharType *b
 	HFONT old_font = nullptr;
 	HFONT cur_font = nullptr;
 
+	if (range.font->fc->IsBuiltInFont()) {
+		range.FallbackShape(buff);
+		return true;
+	}
+
 	while (true) {
 		/* Shape the text run by determining the glyphs needed for display. */
 		int glyphs_used = 0;
-		HRESULT hr = ScriptShape(temp_dc, &_script_cache[range.font->fc->GetSize()], buff + range.pos, range.len, (int)range.glyphs.size(), &range.sa, &range.glyphs[0], &range.char_to_glyph[0], &range.vis_attribs[0], &glyphs_used);
+		HRESULT hr = ScriptShape(temp_dc, &_script_cache[range.font->fc->GetIndex()], buff + range.pos, range.len, (int)range.glyphs.size(), &range.sa, &range.glyphs[0], &range.char_to_glyph[0], &range.vis_attribs[0], &glyphs_used);
 
 		if (SUCCEEDED(hr)) {
 			range.glyphs.resize(glyphs_used);
@@ -179,7 +222,7 @@ static bool UniscribeShapeRun(const UniscribeParagraphLayoutFactory::CharType *b
 			ABC abc;
 			range.advances.resize(range.glyphs.size());
 			range.offsets.resize(range.glyphs.size());
-			hr = ScriptPlace(temp_dc, &_script_cache[range.font->fc->GetSize()], &range.glyphs[0], (int)range.glyphs.size(), &range.vis_attribs[0], &range.sa, &range.advances[0], &range.offsets[0], &abc);
+			hr = ScriptPlace(temp_dc, &_script_cache[range.font->fc->GetIndex()], &range.glyphs[0], (int)range.glyphs.size(), &range.vis_attribs[0], &range.sa, &range.advances[0], &range.offsets[0], &abc);
 			if (SUCCEEDED(hr)) {
 				/* We map our special sprite chars to values that don't fit into a WORD. Copy the glyphs
 				 * into a new vector and query the real glyph to use for these special chars. */
@@ -187,22 +230,12 @@ static bool UniscribeShapeRun(const UniscribeParagraphLayoutFactory::CharType *b
 				for (size_t g_id = 0; g_id < range.glyphs.size(); g_id++) {
 					range.ft_glyphs[g_id] = range.glyphs[g_id];
 				}
-				for (int i = 0; i < range.len; i++) {
-					if (buff[range.pos + i] >= SCC_SPRITE_START && buff[range.pos + i] <= SCC_SPRITE_END) {
-						auto pos = range.char_to_glyph[i];
-						if (range.ft_glyphs[pos] == 0) { // Font doesn't have our special glyph, so remap.
-							range.ft_glyphs[pos] = range.font->fc->MapCharToGlyph(buff[range.pos + i]);
-							range.offsets[pos].dv = (range.font->fc->GetHeight() - ScaleSpriteTrad(FontCache::GetDefaultFontHeight(range.font->fc->GetSize()))) / 2; // Align sprite font to centre
-							range.advances[pos] = range.font->fc->GetGlyphWidth(range.ft_glyphs[pos]);
-						}
-					}
-				}
 
 				range.total_advance = 0;
 				for (size_t i = 0; i < range.advances.size(); i++) {
 #ifdef WITH_FREETYPE
 					/* FreeType and GDI/Uniscribe seems to occasionally disagree over the width of a glyph. */
-					if (range.advances[i] > 0 && range.ft_glyphs[i] != 0xFFFF) range.advances[i] = range.font->fc->GetGlyphWidth(range.ft_glyphs[i]);
+					if (range.advances[i] > 0 && range.glyphs[i] != 0xFFFF) range.advances[i] = range.font->fc->GetGlyphWidth(range.glyphs[i]);
 #endif
 					range.total_advance += range.advances[i];
 				}
@@ -280,11 +313,6 @@ static std::vector<SCRIPT_ITEM> UniscribeItemizeString(UniscribeParagraphLayoutF
 	/* Can't layout an empty string. */
 	if (length == 0) return nullptr;
 
-	/* Can't layout our in-built sprite fonts. */
-	for (auto const &[position, font] : font_mapping) {
-		if (font->fc->IsBuiltInFont()) return nullptr;
-	}
-
 	/* Itemize text. */
 	std::vector<SCRIPT_ITEM> items = UniscribeItemizeString(buff, length);
 	if (items.empty()) return nullptr;

src/string.cpp

@@ -697,7 +697,7 @@ public:
 				 * break point, but we only want word starts. Move to the next location in
 				 * case the new position points to whitespace. */
 				while (pos != icu::BreakIterator::DONE &&
-						IsWhitespace(Utf16DecodeChar((const uint16_t *)&this->utf16_str[pos]))) {
+						IsWhitespace(Utf16DecodeChar(&this->utf16_str[pos]))) {
 					int32_t new_pos = this->word_itr->next();
 					/* Don't set it to DONE if it was valid before. Otherwise we'll return END
 					 * even though the iterator wasn't at the end of the string before. */
@@ -729,7 +729,7 @@ public:
 				 * break point, but we only want word starts. Move to the previous location in
 				 * case the new position points to whitespace. */
 				while (pos != icu::BreakIterator::DONE &&
-						IsWhitespace(Utf16DecodeChar((const uint16_t *)&this->utf16_str[pos]))) {
+						IsWhitespace(Utf16DecodeChar(&this->utf16_str[pos]))) {
 					int32_t new_pos = this->word_itr->previous();
 					/* Don't set it to DONE if it was valid before. Otherwise we'll return END
 					 * even though the iterator wasn't at the start of the string before. */

src/string_func.h

@@ -94,7 +94,7 @@ inline char32_t Utf16DecodeSurrogate(uint lead, uint trail)
  * @param c Pointer to one or two UTF-16 code points.
  * @return Decoded Unicode character.
  */
-inline char32_t Utf16DecodeChar(const uint16_t *c)
+inline char32_t Utf16DecodeChar(const char16_t *c)
 {
 	if (Utf16IsLeadSurrogate(c[0])) {
 		return Utf16DecodeSurrogate(c[0], c[1]);

src/strings.cpp

@@ -2252,42 +2252,60 @@ std::string_view GetCurrentLanguageIsoCode()
 
 /**
  * Check whether there are glyphs missing in the current language.
- * @return If glyphs are missing, return \c true, else return \c false.
+ * @return Bit mask of font sizes have any missing glyphs.
  */
-bool MissingGlyphSearcher::FindMissingGlyphs()
+FontSizes MissingGlyphSearcher::FindMissingGlyphs()
 {
-	InitFontCache(this->Monospace() ? FontSizes{FS_MONO} : FONTSIZES_REQUIRED);
+	for (FontSize size : this->font_sizes) {
+		GetFontCacheSubSetting(size)->fallback_fonts.clear();
+	}
+
+	InitFontCache(this->font_sizes);
+
+	FontSizes bad_fontsizes{};
+
+	for (FontSize size : this->font_sizes) {
+		auto set = this->GetRequiredGlyphs(size);
+		if (set.empty()) continue;
+
+		Debug(fontcache, 0, "Missing {} glyphs in {} font size", set.size(), FontSizeToName(size));
+		bad_fontsizes.Set(size);
+	}
+
+	return bad_fontsizes;
+}
+
+std::set<char32_t> BaseStringMissingGlyphSearcher::GetRequiredGlyphs(FontSizes fontsizes)
+{
+	std::set<char32_t> glyphs{};
 
 	this->Reset();
 	for (auto text = this->NextString(); text.has_value(); text = this->NextString()) {
 		FontSize size = this->DefaultSize();
-		FontCache *fc = FontCache::Get(size);
 		for (char32_t c : Utf8View(*text)) {
 			if (c >= SCC_FIRST_FONT && c <= SCC_LAST_FONT) {
 				size = (FontSize)(c - SCC_FIRST_FONT);
-				fc = FontCache::Get(size);
+				continue;
-			} else if (!IsInsideMM(c, SCC_SPRITE_START, SCC_SPRITE_END) && IsPrintable(c) && !IsTextDirectionChar(c) && fc->MapCharToGlyph(c, false) == 0) {
-				/* The character is printable, but not in the normal font. This is the case we were testing for. */
-				std::string size_name;
-
-				switch (size) {
-					case FS_NORMAL: size_name = "medium"; break;
-					case FS_SMALL: size_name = "small"; break;
-					case FS_LARGE: size_name = "large"; break;
-					case FS_MONO: size_name = "mono"; break;
-					default: NOT_REACHED();
 			}
 
-				Debug(fontcache, 0, "Font is missing glyphs to display char 0x{:X} in {} font size", (int)c, size_name);
+			if (IsInsideMM(c, SCC_SPRITE_START, SCC_SPRITE_END)) continue;
-				return true;
+			if (!IsPrintable(c) || IsTextDirectionChar(c)) continue;
+			if (fontsizes.Test(size)) continue;
+			if (FontCache::GetFontIndexForCharacter(size, c) != INVALID_FONT_INDEX) continue;
+
+			glyphs.insert(c);
 		}
 	}
-	}
+
-	return false;
+	return glyphs;
 }
 
 /** Helper for searching through the language pack. */
-class LanguagePackGlyphSearcher : public MissingGlyphSearcher {
+class LanguagePackGlyphSearcher : public BaseStringMissingGlyphSearcher {
+public:
+	LanguagePackGlyphSearcher() : BaseStringMissingGlyphSearcher({FS_NORMAL, FS_SMALL, FS_LARGE}) {}
+
+private:
 	uint i; ///< Iterator for the primary language tables.
 	uint j; ///< Iterator for the secondary language tables.
 
@@ -2316,26 +2334,11 @@ class LanguagePackGlyphSearcher : public MissingGlyphSearcher {
 
 		return ret;
 	}
-
-	bool Monospace() override
-	{
-		return false;
-	}
-
-	void SetFontNames([[maybe_unused]] FontCacheSettings *settings, [[maybe_unused]] std::string_view font_name, [[maybe_unused]] const void *os_data) override
-	{
-#if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
-		settings->small.font = font_name;
-		settings->medium.font = font_name;
-		settings->large.font = font_name;
-
-		settings->small.os_handle = os_data;
-		settings->medium.os_handle = os_data;
-		settings->large.os_handle = os_data;
-#endif
-	}
 };
 
+static LanguagePackGlyphSearcher _language_pack_searcher;
+
+
 /**
  * Check whether the currently loaded language pack
  * uses characters that the currently loaded font
@@ -2351,22 +2354,17 @@ class LanguagePackGlyphSearcher : public MissingGlyphSearcher {
  */
 void CheckForMissingGlyphs(bool base_font, MissingGlyphSearcher *searcher)
 {
-	static LanguagePackGlyphSearcher pack_searcher;
+	if (searcher == nullptr) searcher = &_language_pack_searcher;
-	if (searcher == nullptr) searcher = &pack_searcher;
+	FontSizes bad_mask = searcher->FindMissingGlyphs();
-	bool bad_font = !base_font || searcher->FindMissingGlyphs();
+	bool bad_font = bad_mask.Any();
+
 #if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
-	if (bad_font) {
+	if (bad_mask.Any()) {
 		/* We found an unprintable character... lets try whether we can find
 		 * a fallback font that can print the characters in the current language. */
 		bool any_font_configured = !_fcsettings.medium.font.empty();
-		FontCacheSettings backup = _fcsettings;
 
-		_fcsettings.mono.os_handle = nullptr;
+		bad_font = !FontProviderManager::SetFallbackFont(_langpack.langpack->isocode, bad_mask, searcher);
-		_fcsettings.medium.os_handle = nullptr;
-
-		bad_font = !FontProviderManager::SetFallbackFont(&_fcsettings, _langpack.langpack->isocode, searcher);
-
-		_fcsettings = std::move(backup);
 
 		if (!bad_font && any_font_configured) {
 			/* If the user configured a bad font, and we found a better one,
@@ -2383,7 +2381,7 @@ void CheckForMissingGlyphs(bool base_font, MissingGlyphSearcher *searcher)
 			/* Our fallback font does miss characters too, so keep the
 			 * user chosen font as that is more likely to be any good than
 			 * the wild guess we made */
-			InitFontCache(searcher->Monospace() ? FontSizes{FS_MONO} : FONTSIZES_REQUIRED);
+			InitFontCache(bad_mask);
 		}
 	}
 #endif
@@ -2400,12 +2398,12 @@ void CheckForMissingGlyphs(bool base_font, MissingGlyphSearcher *searcher)
 		ShowErrorMessage(GetEncodedString(STR_JUST_RAW_STRING, std::move(err_str)), {}, WL_WARNING);
 
 		/* Reset the font width */
-		LoadStringWidthTable(searcher->Monospace() ? FontSizes{FS_MONO} : FONTSIZES_REQUIRED);
+		LoadStringWidthTable(bad_mask);
 		return;
 	}
 
 	/* Update the font with cache */
-	LoadStringWidthTable(searcher->Monospace() ? FontSizes{FS_MONO} : FONTSIZES_REQUIRED);
+	LoadStringWidthTable(searcher->font_sizes);
 
 #if !(defined(WITH_ICU_I18N) && defined(WITH_HARFBUZZ)) && !defined(WITH_UNISCRIBE) && !defined(WITH_COCOA)
 	/*

src/strings_func.h

@@ -157,9 +157,31 @@ EncodedString GetEncodedString(StringID string, const Args&... args)
  */
 class MissingGlyphSearcher {
 public:
+	FontSizes font_sizes; ///< Font sizes to search for.
+
+	MissingGlyphSearcher(FontSizes font_sizes) : font_sizes(font_sizes) {}
+
 	/** Make sure everything gets destructed right. */
 	virtual ~MissingGlyphSearcher() = default;
 
+	/**
+	 * Test if any glyphs are missing.
+	 * @return Font sizes which have missing glyphs.
+	 */
+	FontSizes FindMissingGlyphs();
+
+	/**
+	 * Get set of glyphs required for the current language.
+	 * @param fontsizes Font sizes to test.
+	 * @return Set of required glyphs.
+	 **/
+	virtual std::set<char32_t> GetRequiredGlyphs(FontSizes fontsizes) = 0;
+};
+
+class BaseStringMissingGlyphSearcher : public MissingGlyphSearcher {
+public:
+	BaseStringMissingGlyphSearcher(FontSizes font_sizes) : MissingGlyphSearcher(font_sizes) {}
+
 	/**
 	 * Get the next string to search through.
 	 * @return The next string or nullopt if there is none.
@@ -177,23 +199,9 @@ public:
 	 */
 	virtual void Reset() = 0;
 
-	/**
+	std::set<char32_t> GetRequiredGlyphs(FontSizes fontsizes) override;
-	 * Whether to search for a monospace font or not.
-	 * @return True if searching for monospace.
-	 */
-	virtual bool Monospace() = 0;
-
-	/**
-	 * Set the right font names.
-	 * @param settings  The settings to modify.
-	 * @param font_name The new font name.
-	 * @param os_data Opaque pointer to OS-specific data.
-	 */
-	virtual void SetFontNames(struct FontCacheSettings *settings, std::string_view font_name, const void *os_data = nullptr) = 0;
-
-	bool FindMissingGlyphs();
 };
 
-void CheckForMissingGlyphs(bool base_font = true, MissingGlyphSearcher *search = nullptr);
+void CheckForMissingGlyphs(bool base_font = true, MissingGlyphSearcher *searcher = nullptr);
 
 #endif /* STRINGS_FUNC_H */

src/survey.cpp

@@ -298,10 +298,16 @@ void SurveyConfiguration(nlohmann::json &survey)
  */
 void SurveyFont(nlohmann::json &survey)
 {
-	survey["small"] = FontCache::Get(FS_SMALL)->GetFontName();
+	for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
-	survey["medium"] = FontCache::Get(FS_NORMAL)->GetFontName();
+		const FontCacheSubSetting *setting = GetFontCacheSubSetting(fs);
-	survey["large"] = FontCache::Get(FS_LARGE)->GetFontName();
+		auto &font = survey[std::string(FontSizeToName(fs))];
-	survey["mono"] = FontCache::Get(FS_MONO)->GetFontName();
+		font["configured"]["font"] = setting->font;
+		font["configured"]["size"] = setting->size;
+	}
+	for (const auto &fc : FontCache::Get()) {
+		auto &font = survey[std::string(FontSizeToName(fc->GetSize()))];
+		font["active"].push_back(fc->GetFontName());
+	}
 }
 
 /**

src/tests/mock_fontcache.h

@@ -19,20 +19,22 @@ public:
 	MockFontCache(FontSize fs) : FontCache(fs)
 	{
 		this->height = FontCache::GetDefaultFontHeight(this->fs);
+		FontCache::UpdateCharacterHeight(this->fs);
 	}
 
 	void ClearFontCache() override {}
 	const Sprite *GetGlyph(GlyphID) override { return nullptr; }
 	uint GetGlyphWidth(GlyphID) override { return this->height / 2; }
 	bool GetDrawGlyphShadow() override { return false; }
-	GlyphID MapCharToGlyph(char32_t key, [[maybe_unused]] bool allow_fallback = true) override { return key; }
+	GlyphID MapCharToGlyph(char32_t key) override { return key; }
 	std::string GetFontName() override { return "mock"; }
 	bool IsBuiltInFont() override { return true; }
 
 	static void InitializeFontCaches()
 	{
+		FontCache::caches.clear();
 		for (FontSize fs = FS_BEGIN; fs != FS_END; fs++) {
-			if (FontCache::caches[fs] == nullptr) new MockFontCache(fs); /* FontCache inserts itself into to the cache. */
+			new MockFontCache(fs); /* FontCache inserts itself into to the cache. */
 		}
 	}
 };

src/textfile_gui.cpp

@@ -83,7 +83,7 @@ static WindowDesc _textfile_desc(
 	_nested_textfile_widgets
 );
 
-TextfileWindow::TextfileWindow(Window *parent, TextfileType file_type) : Window(_textfile_desc), file_type(file_type)
+TextfileWindow::TextfileWindow(Window *parent, TextfileType file_type) : Window(_textfile_desc), BaseStringMissingGlyphSearcher(FS_MONO), file_type(file_type)
 {
 	/* Init of nested tree is deferred.
 	 * TextfileWindow::ConstructWindow must be called by the inheriting window. */
@@ -754,19 +754,6 @@ bool TextfileWindow::IsTextWrapped() const
 	return this->lines[this->search_iterator++].text;
 }
 
-/* virtual */ bool TextfileWindow::Monospace()
-{
-	return true;
-}
-
-/* virtual */ void TextfileWindow::SetFontNames([[maybe_unused]] FontCacheSettings *settings, [[maybe_unused]] std::string_view font_name, [[maybe_unused]] const void *os_data)
-{
-#if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
-	settings->mono.font = font_name;
-	settings->mono.os_handle = os_data;
-#endif
-}
-
 #if defined(WITH_ZLIB)
 
 /**

src/textfile_gui.h

@@ -19,7 +19,7 @@
 std::optional<std::string> GetTextfile(TextfileType type, Subdirectory dir, std::string_view filename);
 
 /** Window for displaying a textfile */
-struct TextfileWindow : public Window, MissingGlyphSearcher {
+struct TextfileWindow : public Window, BaseStringMissingGlyphSearcher {
 	TextfileType file_type{}; ///< Type of textfile to view.
 	Scrollbar *vscroll = nullptr; ///< Vertical scrollbar.
 	Scrollbar *hscroll = nullptr; ///< Horizontal scrollbar.
@@ -38,8 +38,6 @@ struct TextfileWindow : public Window, MissingGlyphSearcher {
 	void Reset() override;
 	FontSize DefaultSize() override;
 	std::optional<std::string_view> NextString() override;
-	bool Monospace() override;
-	void SetFontNames(FontCacheSettings *settings, std::string_view font_name, const void *os_data) override;
 	void ScrollToLine(size_t line);
 	bool IsTextWrapped() const;