Adding Localization support (#159)

* Innitial commit

Localization for retro-go using a simple 0(n) lookup function called rg_gettext()

* adding language settings in options menu

* adding more gettext()

* new lookup function

* adding "For these changes to take effect you must restart your device." gui alert + fixing gettext() function

* modifying the gui dialog

* updating struct syntax

* update struct syntax (again)

* creating the python tool for localization

* updating tool + adding missing translations

* moving stuff to libs + starting writing readme

* adding missing "libs/localization" folder import in cmakelist + added the "fixme for rg_system"

* synthax adjust + moving back stuff from libs to retro-go

* removing trailing spaces

* adding the enum for language ids

* updating documentation according to the latest changes

* small tweaks

* Moved LOCALIZATION.md to the root folder

Whilst it is mostly relevant to libretro-go, it really is project-wide documentation.

* rg_localization: Got rid of the switch, made GUI dynamic

This makes adding a language more straightforward.

I kept the *msg *fr *en for now to avoid updating translations.h, but it could be replaced by the GCC extension as such:

[RG_LANG_EN] = "...",
[RG_LANG_FR] = "...",

So that adding a language is really just updating the enum...

* rg_localization: translations is const, we can use RG_COUNT

* rg_gui: Fixed language selection

* rg_localization: No need to validate rg_language in rg_gettext

It should always be valid, there's no need to validate it.

* rg_gui: Show language name in the log

* rg_localization: Got rid of the Translation struct

I am not 100% positive this is a good move...

Benefits:
- One less thing to change when adding a language
- Less code is always better

Cons:
- It doesn't make it clear what the "key" is (the english text)
- If in the future we need to add things like flags it will have to be returned to a struct

* updated python tool + updating translations

* added missing translations

* audio filter wrong translation

* fix : "a propose de retro-go"

---------

Co-authored-by: Alex Duchesne <ducalex007@gmail.com>

LOCALIZATION.md

@@ -0,0 +1,32 @@
+This document describes the localization protocol used in Retro-go
+
+
+# C files
+translation.h contains the original messages (in english) and the corresponding translations ex:
+````c
+{
+    [RG_LANG_EN] = "Yes",
+    [RG_LANG_FR] = "Oui",
+    [RG_LANG_ES] = "Si",
+},
+````
+
+If you want to add your own language :
+
+You should update the enum accordingly (in rg_localization.h):
+````c
+typedef enum
+{
+    RG_LANG_EN,
+    RG_LANG_FR,
+
+    RG_LANG_ES, // <-- to add spanish translation
+
+    RG_LANG_MAX
+} rg_language_t;
+````
+
+
+# Python tool
+`rg_locate_str.py` is a simple python tool that locate every string preceded by `_("` pattern in each file of Retro-go project
+Then the tool compare theses strings to the ones in `translations.h` and put the missing ones in a .txt file called missing_translation.txt

components/retro-go/libs/netplay/rg_netplay.c

@@ -360,19 +360,19 @@ void rg_netplay_init(netplay_callback_t callback)
 
 bool rg_netplay_quick_start(void)
 {
-    const char *status_msg = "Initializing...";
+    const char *status_msg = _("Initializing...");
     const char *screen_msg = NULL;
     // int timeout = 100;
 
     rg_display_clear(0);
 
     const rg_gui_option_t options[] = {
-        {1, "Host Game (P1)", NULL, RG_DIALOG_FLAG_NORMAL, NULL},
-        {2, "Find Game (P2)", NULL, RG_DIALOG_FLAG_NORMAL, NULL},
+        {1, _("Host Game (P1)"), NULL, RG_DIALOG_FLAG_NORMAL, NULL},
+        {2, _("Find Game (P2)"), NULL, RG_DIALOG_FLAG_NORMAL, NULL},
         RG_DIALOG_END
     };
 
-    int ret = rg_gui_dialog("Netplay", options, 0);
+    int ret = rg_gui_dialog(_("Netplay"), options, 0);
 
     if (ret == 1)
         rg_netplay_start(NETPLAY_MODE_HOST);
@@ -387,31 +387,31 @@ bool rg_netplay_quick_start(void)
         {
             case NETPLAY_STATUS_CONNECTED:
                 return remote_player->game_id == local_player->game_id
-                    || rg_gui_confirm("Netplay", "ROMs not identical. Continue?", 1);
+                    || rg_gui_confirm(_("Netplay"), _("ROMs not identical. Continue?"), 1);
                 break;
 
             case NETPLAY_STATUS_HANDSHAKE:
-                status_msg = "Exchanging info...";
+                status_msg = _("Exchanging info...");
                 break;
 
             case NETPLAY_STATUS_CONNECTING:
-                status_msg = "Connecting...";
+                status_msg = _("Connecting...");
                 break;
 
             case NETPLAY_STATUS_DISCONNECTED:
-                status_msg = "Unable to find host!";
+                status_msg = _("Unable to find host!");
                 break;
 
             case NETPLAY_STATUS_STOPPED:
-                status_msg = "Connection failed!";
+                status_msg = _("Connection failed!");
                 break;
 
             case NETPLAY_STATUS_LISTENING:
-                status_msg = "Waiting for peer...";
+                status_msg = _("Waiting for peer...");
                 break;
 
             default:
-                status_msg = "Unknown status...";
+                status_msg = _("Unknown status...");
         }
 
         if (screen_msg != status_msg)