Looks like SDL2_Pango can find our fonts now

Made sure to add our font dir (e.g., /usr/local/share/tuxpaint/fonts/)
to FontConfig's directories before trying to load uifont!

Also, update font names to match what we ship with Tux Paint.
WIP -- Would like to supply some alternatives.

docs/CHANGES.txt

@@ -70,22 +70,14 @@ https://tuxpaint.org/
       Closes https://sourceforge.net/p/tuxpaint/feature-requests/146/
       Bill Kendrick <bill@newbreedsoftware.com>
 
-    * WIP Different default fonts may be set on a per-locale basis
-      (hard-coded into Tux Paint).  Most locales still use "DejaVu Sans",
-      if available.  As of 0.9.31, things are configured as:
-      + Arabic: Nice
-      + Gujarati: Lohit Gujarati
-      + Hebrew: Nachlieli CLM
-      + Hindi: Lohit Devanagari
-      + Japanese: TBD <<FIXME>>
-      + Korean: Baekmuk Gulim
-      + Thai: Garuda
-      + Tibetan: Tsampa Keyboard
+    * Different default fonts once again used on a per-locale basis.
       (This returns us to how Tux Paint behaved when we used
       SDL_ttf to directly load fonts for the UI, and used TTF font files
-      that we ship in the `fonts/locale/` directory.)
+      that we ship in the `fonts/locale/` directory.  We now ask Pango,
+      via FontConfig, to look there for fonts.)
       Closes https://sourceforge.net/p/tuxpaint/feature-requests/240/
       Bill Kendrick <bill@newbreedsoftware.com> (code)
+      h/t Mark Kim & TOYAMA Shin-ichi
 
   * Bug Fixes:
     ----------

src/fonts.c

@@ -175,42 +175,23 @@ static void reliable_read(int fd, void *buf, size_t count);
 
 const char * PANGO_DEFAULT_FONT = "DejaVu Sans";
 
+/* Names of the fonts we include in `fonts/locale/` */
+// (Try `otfinfo --info fonts/locale/*.ttf | grep "Full name:"`)
 default_locale_font_t default_local_fonts[] = {
-  // Initially based on "otfinfo --info fonts/locale/*.ttf | grep "Full name:"
-  {
-   LANG_JA,
-   "TakaoPGothic" /* Included in Ubuntu "fonts-takao-gothic" package */
-   // FIXME: Shin-ichi recommend something, please! -bjk 2023.06.08
-  },
-  {
-   LANG_KO,
-   "Baekmuk Gulim"
-  },
-  {
-   LANG_BO, // NOTE: Our current translation is Wylie transliterated, not Unicode! */
-   "Tsampa Keyboard" /* FIXME: Not packaged in Ubuntu! */
-  },
-  {
-   LANG_GU,
-   "Lohit Gujarati" /* Included in Ubuntu "fonts-lohit-gujr" package */
-  },
-  {
-   LANG_TH,
-   "Garuda" /* Included in Ubuntu "fonts-tlwg-garuda-ttf" package */
-  },
-  {
-   LANG_AR,
-   "Nice" /* Included in Ubuntu "fonts-arabeyes" package (ae_Nice) */
-  },
-  {
-   LANG_HE,
-   "Nachlieli CLM" /* Inclued in Ubuntu "culmus" package */
-  },
-  {
-   LANG_HI,
-   "Lohit Devanagari" /* Included in Ubuntu "fonts-lohit-deva" package */
-  },
-  {-1, NULL},
+  { LANG_AR, "ae_Nice" },
+  { LANG_BO, "Tsampa Keyboard" }, // NOTE: Our current translation is Wylie transliterated, not Unicode! */
+  { LANG_EL, "Thryomanes" },
+  { LANG_GU, "Lohit Gujarati" },
+  { LANG_HE, "Nachlieli Light" },
+  { LANG_HI, "Raghindi" },
+  { LANG_JA, "GJGothicPNSubset" },
+  { LANG_KA, "TuxPaint Georgian" },
+  { LANG_KO, "Baekmuk Gulim" },
+  { LANG_TA, "TSCu_Comic" },
+  { LANG_TE, "Vemana2000" },
+  { LANG_TH, "Garuda" },
+  { LANG_ZH_TW, "SubsetForTuxPaint" },
+  { -1, NULL },
 }; 
 
 void TuxPaint_Font_CloseFont(TuxPaint_Font * tpf)

src/tuxpaint.c

@@ -9326,47 +9326,10 @@ static int generate_fontconfig_cache_real(void)
   TuxPaint_Font *tmp_font;
   SDL_Surface *tmp_surf;
   SDL_Color black = { 0, 0, 0, 0 };
-  FcBool fontAddStatus;
-  const char * locale_fontdir;
 
   DEBUG_PRINTF("-- Hello from generate_fontconfig_cache() (thread # %d)\n", SDL_ThreadID());
 
 
-  /* Add Tux Paint's own set of fonts to FontConfig,
-     so SDL2_Pango can find and use them */
-  locale_fontdir = "/usr/local/share/tuxpaint/fonts"; // FIXME
-
-  fontAddStatus = FcConfigAppFontAddDir(FcConfigGetCurrent(), (const FcChar8 *) locale_fontdir);
-  if (fontAddStatus == FcFalse)
-  {
-    fprintf(stderr, "Unable to add font dir %s\n", locale_fontdir);
-  }
-
-  /* ARGH: Why is '/usr/local/share/tuxpaint/fonts' not
-     coming back in the list of font dirs (below)?!
-
-     I tried both of these & they did not help.
-     Documentation out there is very vague; Google barely helping.
-
-     -bjk 2023.06.12
-  */
-  printf("Rescanning fonts..."); fflush(stdout);
-  FcDirCacheRead(locale_fontdir, FcTrue /* force */, FcConfigGetCurrent());
-  FcDirCacheRescan(locale_fontdir, FcConfigGetCurrent());
-  printf("done\n");
-
-  if (SDL_TRUE) // FIXME
-  {
-    FcStrList *str_list;
-    FcChar8 *path;
-    str_list = FcConfigGetFontDirs(FcConfigGetCurrent());
-    printf("FontConfigGetFontDirs():\n");
-    while ((path = FcStrListNext(str_list)) != NULL) {
-      printf(" * %s\n", (const char *) path);
-    }
-    printf("\n");
-  }
-
   tmp_font = TuxPaint_Font_OpenFont(PANGO_DEFAULT_FONT, NULL, 12); /* always just using the default font for the purpose of getting FontConfig to generate its cache */
 
   if (tmp_font != NULL)
@@ -28152,6 +28115,8 @@ static void setup_config(char *argv[])
   if (tmpcfg.tp_ui_font)
   {
     char * tmp_str;
+    FcBool fontAddStatus;
+    const char locale_fontdir[MAX_PATH];
 
     if (strcmp(tmpcfg.tp_ui_font, "default") == 0)
     {
@@ -28164,6 +28129,36 @@ static void setup_config(char *argv[])
       printf/*DEBUG_PRINTF*/("Requested UI font described by \"%s\"\n", tp_ui_font);
     }
 
+    /* Add Tux Paint's own set of fonts to FontConfig,
+       so SDL2_Pango can find and use them */
+    snprintf(locale_fontdir, sizeof(locale_fontdir), "%s/fonts", DATA_PREFIX);
+
+    fontAddStatus = FcConfigAppFontAddDir(FcConfigGetCurrent(), (const FcChar8 *) locale_fontdir);
+    if (fontAddStatus == FcFalse)
+    {
+      fprintf(stderr, "Unable to add font dir %s\n", locale_fontdir);
+    }
+
+    /* FIXME: Unclear whether this is necessary? -bjk 2023.06.12 */
+    DEBUG_PRINTF("Rescanning fonts..."); fflush(stdout);
+    FcDirCacheRead((const FcChar8 *) locale_fontdir, FcTrue /* force */, FcConfigGetCurrent());
+    FcDirCacheRescan((const FcChar8 *) locale_fontdir, FcConfigGetCurrent());
+    DEBUG_PRINTF("done\n");
+
+#ifdef DEBUG
+    {
+      FcStrList *str_list;
+      FcChar8 *path;
+      str_list = FcConfigGetFontDirs(FcConfigGetCurrent());
+      printf("FcConfigGetFontDirs():\n");
+      while ((path = FcStrListNext(str_list)) != NULL) {
+        printf(" * %s\n", (const char *) path);
+      }
+      printf("\n");
+    }
+#endif
+
+
     tmp_str = ask_pango_for_font(tp_ui_font);
     if (tmp_str != NULL)
     {