Workaround for fonts with zero ascender/descender in horizontal header.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@24002 b3059339-0415-0410-9bf9-f77b7e298cf2

diff --git a/libass/ass_font.c b/libass/ass_font.c
index 77a585fcafa8bac5e65eefa0f94bbf1dbdf82905..b93c41e1b1c0eb141da331de06c3b5d10c4dba58 100644 (file)
--- a/libass/ass_font.c
+++ b/libass/ass_font.c
@@ -89,6 +89,25 @@ static int find_font(ass_library_t* library, char* name)
 
 static void face_set_size(FT_Face face, double size);
 
+static void buggy_font_workaround(FT_Face face)
+{
+       // Some fonts have zero Ascender/Descender fields in 'hhea' table.
+       // In this case, get the information from 'os2' table or, as
+       // a last resort, from face.bbox.
+       if (face->ascender + face->descender == 0 || face->height == 0) {
+               TT_OS2 *os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2);
+               if (os2) {
+                       face->ascender = os2->sTypoAscender;
+                       face->descender = os2->sTypoDescender;
+                       face->height = face->ascender - face->descender;
+               } else {
+                       face->ascender = face->bbox.yMax;
+                       face->descender = face->bbox.yMin;
+                       face->height = face->ascender - face->descender;
+               }
+       }
+}
+
 /**
  * \brief Select a face with the given charcode and add it to ass_font_t
  * \return index of the new face in font->faces, -1 if failed
@@ -123,6 +142,7 @@ static int add_face(void* fc_priv, ass_font_t* font, uint32_t ch)
                }
        }
        charmap_magic(face);
+       buggy_font_workaround(face);
        
        font->faces[font->n_faces++] = face;
        update_transform(font);