[truetype] Fix 'sbix' table handling.

* src/sfnt/ttsbit.c (tt_face_load_sbix_image): Correct calculation of
'metrics->horiBearingY'.
Set vertical metrics.

* src/sfnt/sfobjs.c (sfnt_load_face): Adjust setting of `FT_FACE_FLAG_SBIX`.
Handle metrics of fonts with 'sbix' table.

* src/truetype/ttgload.c (TT_Load_Glyph): For 'sbix' embedded bitmaps, apply
bbox offset and bearing values of the corresponding glyph in the 'glyf'
table if it exists and has a contour.

* src/truetype/ttobjs.c (tt_face_init): Handle font with 'sbix' table.

Fixes issue #998.

2 files changed, 27 insertions, 13 deletions

diff --git a/src/sfnt/sfobjs.c b/src/sfnt/sfobjs.c
index 008962b2f..614ff68de 100644
--- a/src/sfnt/sfobjs.c
+++ b/src/sfnt/sfobjs.c
@@ -851,12 +851,6 @@
     is_apple_sbit = 0;
     is_apple_sbix = !face->goto_table( face, TTAG_sbix, stream, 0 );
 
-    /* Apple 'sbix' color bitmaps are rendered scaled and then the 'glyf'
-     * outline rendered on top.  We don't support that yet, so just ignore
-     * the 'glyf' outline and advertise it as a bitmap-only font. */
-    if ( is_apple_sbix )
-      has_outline = FALSE;
-
     /* if this font doesn't contain outlines, we try to load */
     /* a `bhed' table                                        */
     if ( !has_outline && sfnt->load_bhed )
@@ -1059,10 +1053,12 @@
 
       if ( has_outline == TRUE )
       {
-        flags |= FT_FACE_FLAG_SCALABLE;   /* scalable outlines */
-
-        if ( face->sbit_table_type == TT_SBIT_TABLE_TYPE_SBIX )
-          flags |= FT_FACE_FLAG_SBIX;     /* and 'sbix' bitmaps */
+        /* by default (and for backward compatibility) we handle */
+        /* fonts with an 'sbix' table as bitmap-only             */
+        if ( is_apple_sbix )
+          flags |= FT_FACE_FLAG_SBIX;     /* with 'sbix' bitmaps */
+        else
+          flags |= FT_FACE_FLAG_SCALABLE; /* scalable outlines */
       }
 
       /* The sfnt driver only supports bitmap fonts natively, thus we */
@@ -1286,7 +1282,8 @@
        *
        * Set up metrics.
        */
-      if ( FT_IS_SCALABLE( root ) )
+      if ( FT_IS_SCALABLE( root ) ||
+           FT_HAS_SBIX( root )    )
       {
         /* XXX What about if outline header is missing */
         /*     (e.g. sfnt wrapped bitmap)?             */
diff --git a/src/sfnt/ttsbit.c b/src/sfnt/ttsbit.c
index 179e9cc55..0ab602632 100644
--- a/src/sfnt/ttsbit.c
+++ b/src/sfnt/ttsbit.c
@@ -1580,17 +1580,34 @@
 
     if ( !error )
     {
-      FT_Short   abearing;
+      FT_Short   abearing; /* not used here */
       FT_UShort  aadvance;
 
 
       tt_face_get_metrics( face, FALSE, glyph_index, &abearing, &aadvance );
 
       metrics->horiBearingX = (FT_Short)originOffsetX;
-      metrics->horiBearingY = (FT_Short)( -originOffsetY + metrics->height );
+      metrics->vertBearingX = (FT_Short)originOffsetX;
+
+      metrics->horiBearingY = (FT_Short)( originOffsetY + metrics->height );
+      metrics->vertBearingY = (FT_Short)originOffsetY;
+
       metrics->horiAdvance  = (FT_UShort)( aadvance *
                                            face->root.size->metrics.x_ppem /
                                            face->header.Units_Per_EM );
+
+      if ( face->vertical_info )
+        tt_face_get_metrics( face, TRUE, glyph_index, &abearing, &aadvance );
+      else if ( face->os2.version != 0xFFFFU )
+        aadvance = (FT_UShort)FT_ABS( face->os2.sTypoAscender -
+                                      face->os2.sTypoDescender );
+      else
+        aadvance = (FT_UShort)FT_ABS( face->horizontal.Ascender -
+                                      face->horizontal.Descender );
+
+      metrics->vertAdvance  = (FT_UShort)( aadvance *
+                                           face->root.size->metrics.x_ppem /
+                                           face->header.Units_Per_EM );
     }
 
     return error;