Let HarfBuzz decide which script, direction and language to use in ca…

…se not set

Text has rules and settings needed for its rendering depending on its characters. Scripts, text direction and language are settings that should be changed depending on the characters and their context. These change the visual effect on the rendered text.

At the moment SDL_TTF provides us the possibility to set any of these three settings but always defaults to an invalid setting on each. With hb_buffer_guess_segment_properties() these could be deducted if not set and it should be the default for rendering text correctly.

(cherry picked from commit 7b3d839)

SDL_ttf.c

@@ -3234,6 +3234,7 @@ static int TTF_Size_Internal(TTF_Font *font,
     /* Set global configuration */
     hb_buffer_set_direction(hb_buffer, hb_direction);
     hb_buffer_set_script(hb_buffer, hb_script);
+    hb_buffer_guess_segment_properties(hb_buffer);
 
     /* Layout the text */
     hb_buffer_add_utf8(hb_buffer, text, -1, 0, -1);