prep work (everything but fontengine)

doc/lua_api.md

@@ -266,7 +266,7 @@ The main Lua script. Running this script should register everything it
 wants to register. Subsequent execution depends on Luanti calling the
 registered callbacks.
 
-### `textures`, `sounds`, `media`, `models`, `locale`
+### `textures`, `sounds`, `media`, `models`, `locale`, `fonts`
 
 Media files (textures, sounds, whatever) that will be transferred to the
 client and will be available for use by the mod and translation files for
@@ -279,6 +279,7 @@ Accepted formats are:
     images: .png, .jpg, .tga
     sounds: .ogg vorbis
     models: .x, .b3d, .obj, (since version 5.10:) .gltf, .glb
+    fonts: .ttf (since version 5.?, see notes below) <!-- TODO before merge -->
 
 Other formats won't be sent to the client (e.g. you can store .blend files
 in a folder for convenience, without the risk that such files are transferred)
@@ -343,6 +344,22 @@ For example, if your model used an emissive material,
 you should expect that a future version of Luanti may respect this,
 and thus cause your model to render differently there.
 
+#### Custom fonts
+
+You can supply custom fonts in TrueType Font (TTF) format.
+In the future, having multiple custom fonts and the ability to switch between them is planned,
+but for now this feature is limited to the ability to override Luanti's default fonts via mods.
+It is recommended that this only be used by game mods. The names are self-explanatory:
+
+* `regular.ttf`
+* `bold.ttf`
+* `italic.ttf`
+* `bold_italic.ttf`
+* `mono.ttf`
+* `mono_bold.ttf`
+* `mono_bold_italic.ttf`
+* `fallback.ttf` <!-- TODO is this a good idea? -->
+
 Naming conventions
 ------------------
 

src/client/client.cpp

@@ -9,6 +9,7 @@
 #include <IFileSystem.h>
 #include <json/json.h>
 #include "client.h"
+#include "client/fontengine.h"
 #include "network/clientopcodes.h"
 #include "network/connection.h"
 #include "network/networkpacket.h"
@@ -360,6 +361,9 @@ Client::~Client()
 	for (auto &csp : m_sounds_client_to_server)
 		m_sound->freeId(csp.first);
 	m_sounds_client_to_server.clear();
+
+	// Go back to our mainmenu fonts
+	g_fontengine->clearMediaFonts();
 }
 
 void Client::connect(const Address &address, const std::string &address_name,
@@ -833,6 +837,13 @@ bool Client::loadMedia(const std::string &data, const std::string &filename,
 		return true;
 	}
 
+	const char *font_ext[] = {".ttf", NULL};
+	name = removeStringEnd(filename, font_ext);
+	if (!name.empty()) {
+		g_fontengine->setMediaFont(name, data);
+		return true;
+	}
+
 	errorstream << "Client: Don't know how to load file \""
 		<< filename << "\"" << std::endl;
 	return false;

src/server.cpp

@@ -2541,6 +2541,9 @@ bool Server::addMediaFile(const std::string &filename,
 		".x", ".b3d", ".obj", ".gltf", ".glb",
 		// Translation file formats
 		".tr", ".po", ".mo",
+		// Fonts
+		// TODO throw a warning and ignore file if name is not one of the few recognized ones?
+		".ttf",
 		NULL
 	};
 	if (removeStringEnd(filename, supported_ext).empty()) {

src/server/mods.cpp

@@ -87,5 +87,6 @@ void ServerModManager::getModsMediaPaths(std::vector<std::string> &paths) const
 		fs::GetRecursiveDirs(paths, spec.path + DIR_DELIM + "media");
 		fs::GetRecursiveDirs(paths, spec.path + DIR_DELIM + "models");
 		fs::GetRecursiveDirs(paths, spec.path + DIR_DELIM + "locale");
+		fs::GetRecursiveDirs(paths, spec.path + DIR_DELIM + "fonts");
 	}
 }