UI: BLF Use Custom NotDef Not Last Resort

This PR removes the "Last Resort" font from the stack. Instead uses a
custom "not def" glyph, defined as an SVG file. This glyph is shown
when requesting a character not found for text inputs, text editor, and
for Sequencer text strips.

Pull Request: https://projects.blender.org/blender/blender/pulls/132032

source/blender/blenfont/intern/blf_font.cc

@@ -1985,7 +1985,6 @@ struct FaceDetails {
 
 /* Details about the fallback fonts we ship, so that we can load only when needed. */
 static const FaceDetails static_face_details[] = {
-    {"lastresort.woff2", UINT32_MAX, UINT32_MAX, UINT32_MAX, UINT32_MAX},
     {"Noto Sans CJK Regular.woff2",
      0,
      TT_UCR_CJK_SYMBOLS | TT_UCR_HIRAGANA | TT_UCR_KATAKANA | TT_UCR_BOPOMOFO | TT_UCR_CJK_MISC |

source/blender/blenfont/intern/blf_glyph.cc

@@ -811,17 +811,12 @@ static FT_UInt blf_glyph_index_from_charcode(FontBLF **font, const uint charcode
     }
   }
 
-  /* Next look in the rest. Also check if we have a last-resort font. */
-  FontBLF *last_resort = nullptr;
+  /* Next look in the rest. */
   for (int i = 0; i < BLF_MAX_FONT; i++) {
     FontBLF *f = global_font[i];
     if (!f || f == *font || !(f->flags & BLF_DEFAULT)) {
       continue;
     }
-    if (f->flags & BLF_LAST_RESORT) {
-      last_resort = f;
-      continue;
-    }
     if (coverage_bit >= 0 && !blf_font_has_coverage_bit(f, coverage_bit)) {
       glyph_index = blf_get_char_index(f, charcode);
       if (glyph_index) {
@@ -835,15 +830,6 @@ static FT_UInt blf_glyph_index_from_charcode(FontBLF **font, const uint charcode
   printf("Unicode character U+%04X not found in loaded fonts. \n", charcode);
 #endif
 
-  /* Not found in the stack, return from Last Resort if there is one. */
-  if (last_resort) {
-    glyph_index = blf_get_char_index(last_resort, charcode);
-    if (glyph_index) {
-      *font = last_resort;
-      return glyph_index;
-    }
-  }
-
   return 0;
 }
 
@@ -1370,6 +1356,11 @@ GlyphBLF *blf_glyph_ensure(FontBLF *font, GlyphCacheBLF *gc, const uint charcode
   FontBLF *font_with_glyph = font;
   FT_UInt glyph_index = blf_glyph_index_from_charcode(&font_with_glyph, charcode);
 
+  if (!glyph_index) {
+    /* 1 = id of ICON_CHAR_NOTDEF */
+    return blf_glyph_ensure_icon(gc, 1, false, nullptr);
+  }
+
   if (!blf_ensure_face(font_with_glyph)) {
     return nullptr;
   }

source/blender/blenfont/intern/blf_internal.hh

@@ -202,6 +202,7 @@ GlyphBLF *blf_glyph_ensure_icon(
 
 /**
  * Convert a character's outlines into curves.
+ * \return success if the character was found and converted.
  */
 bool blf_character_to_curves(FontBLF *font,
                              unsigned int unicode,