Warn on freetype missing glyphs.

anntzer · anntzer · commit 209b759d5569 · 2018-04-03T00:58:23.000-07:00
There is an additional call site to FT_Get_Char_Index in
PyFT2Font_get_char_index but that value is directly returned to Python
so it would be easier to check for the value there and handle it
accordingly (plus, in practice, the same warning will be triggered at
the other two call sites at some point anyways).  But I can replace that
by a warning too.
diff --git a/src/ft2font.cpp b/src/ft2font.cpp
@@ -162,9 +162,19 @@ FT2Image::draw_rect_filled(unsigned long x0, unsigned long y0, unsigned long x1,
 
 inline double conv(long v)
 {
-    return double(v) / 64.0;
+    return v / 64.;
 }
 
+FT_UInt ft_get_char_index_or_warn(FT_Face face, FT_ULong charcode)
+{
+    FT_UInt glyph_index = FT_Get_Char_Index(face, charcode);
+    if (!glyph_index) {
+        PyErr_WarnEx(NULL, "Required glyph missing from current font.", 1);
+    }
+    return glyph_index;
+}
+
+
 int FT2Font::get_path_count()
 {
     // get the glyph as a path, a list of (COMMAND, *args) as described in matplotlib.path
@@ -611,7 +621,7 @@ void FT2Font::set_text(
         FT_BBox glyph_bbox;
         FT_Pos last_advance;
 
-        glyph_index = FT_Get_Char_Index(face, codepoints[n]);
+        glyph_index = ft_get_char_index_or_warn(face, codepoints[n]);
 
         // retrieve kerning distance and move pen position
         if (use_kerning && previous && glyph_index) {
@@ -664,7 +674,8 @@ void FT2Font::set_text(
 
 void FT2Font::load_char(long charcode, FT_Int32 flags)
 {
-    int error = FT_Load_Char(face, (unsigned long)charcode, flags);
+    FT_UInt glyph_index = ft_get_char_index_or_warn(face, (FT_ULong)charcode);
+    int error = FT_Load_Glyph(face, glyph_index, flags);
 
     if (error) {
         throw std::runtime_error("Could not load charcode");
diff --git a/src/ft2font_wrapper.cpp b/src/ft2font_wrapper.cpp
@@ -998,8 +998,8 @@ static PyObject *PyFT2Font_get_char_index(PyFT2Font *self, PyObject *args, PyObj
 const char *PyFT2Font_get_sfnt__doc__ =
     "get_sfnt(name)\n"
     "\n"
-    "Get all values from the SFNT names table.  Result is a dictionary whose"
-    "key is the platform-ID, ISO-encoding-scheme, language-code, and"
+    "Get all values from the SFNT names table.  Result is a dictionary whose "
+    "key is the platform-ID, ISO-encoding-scheme, language-code, and "
     "description.\n";
 
 static PyObject *PyFT2Font_get_sfnt(PyFT2Font *self, PyObject *args, PyObject *kwds)
