Add new load flag FT_LOAD_NO_SVG.

Modern color fonts often contain both an 'SVG' and 'COLR' table.  FreeType
always preferred 'SVG' over 'COLR' (this was a design decision), however,
this might not be the right choice for the user.  The new flags makes
FreeType ignore the 'SVG' table while loading a glyph.

Fixes #1229.

* include/freetype/freetype.h (FT_LOAD_NO_SVG): New macro.

* src/base/ftobjs.c (FT_Load_Glyph), src/cff/cffgload.c (cff_slot_load),
src/truetype/ttgload.c (TT_Load_Glyph): Use it.

docs/CHANGES

@@ -5,6 +5,9 @@ CHANGES BETWEEN 2.13.0 and 2.13.1 (2023-XXX-XX)
   - New function  `FT_Get_Default_Named_Instance` to get the  index of
     the default named instance of an OpenType Variation Font.
 
+  - A new load flag `FT_LOAD_NO_SVG` to make FreeType ignore glyphs in
+    an 'SVG ' table.
+
 
 ======================================================================
 

include/freetype/freetype.h

@@ -3425,10 +3425,11 @@ FT_BEGIN_HEADER
    *
    *     [Since 2.12] If the glyph index maps to an entry in the face's
    *     'SVG~' table, load the associated SVG document from this table and
-   *     set the `format` field of @FT_GlyphSlotRec to @FT_GLYPH_FORMAT_SVG.
-   *     Note that FreeType itself can't render SVG documents; however, the
-   *     library provides hooks to seamlessly integrate an external renderer.
-   *     See sections @ot_svg_driver and @svg_fonts for more.
+   *     set the `format` field of @FT_GlyphSlotRec to @FT_GLYPH_FORMAT_SVG
+   *     ([since 2.13.1] provided @FT_LOAD_NO_SVG is not set).  Note that
+   *     FreeType itself can't render SVG documents; however, the library
+   *     provides hooks to seamlessly integrate an external renderer.  See
+   *     sections @ot_svg_driver and @svg_fonts for more.
    *
    *     [Since 2.10, experimental] If the glyph index maps to an entry in
    *     the face's 'COLR' table with a 'CPAL' palette table (as defined in
@@ -3442,6 +3443,9 @@ FT_BEGIN_HEADER
    *     @FT_Palette_Select instead of setting @FT_LOAD_COLOR for rendering
    *     so that the client application can handle blending by itself.
    *
+   *   FT_LOAD_NO_SVG ::
+   *     [Since 2.13.1] Ignore SVG glyph data when loading.
+   *
    *   FT_LOAD_COMPUTE_METRICS ::
    *     [Since 2.6.1] Compute glyph metrics from the glyph data, without the
    *     use of bundled metrics tables (for example, the 'hdmx' table in
@@ -3507,6 +3511,7 @@ FT_BEGIN_HEADER
 #define FT_LOAD_COLOR                        ( 1L << 20 )
 #define FT_LOAD_COMPUTE_METRICS              ( 1L << 21 )
 #define FT_LOAD_BITMAP_METRICS_ONLY          ( 1L << 22 )
+#define FT_LOAD_NO_SVG                       ( 1L << 24 )
 
   /* */
 

src/base/ftobjs.c

@@ -1019,7 +1019,8 @@
       /*      elegant.                                            */
 
       /* try to load SVG documents if available */
-      if ( FT_HAS_SVG( face ) )
+      if ( ( load_flags & FT_LOAD_NO_SVG ) == 0 &&
+           FT_HAS_SVG( face )                   )
       {
         error = driver->clazz->load_glyph( slot, face->size,
                                            glyph_index,

src/cff/cffgload.c

@@ -356,14 +356,16 @@
 
 #ifdef FT_CONFIG_OPTION_SVG
     /* check for OT-SVG */
-    if ( ( load_flags & FT_LOAD_COLOR ) && face->svg )
+    if ( ( load_flags & FT_LOAD_NO_SVG ) == 0 &&
+         ( load_flags & FT_LOAD_COLOR )       &&
+         face->svg                            )
     {
       /*
        * We load the SVG document and try to grab the advances from the
        * table.  For the bearings we rely on the presetting hook to do that.
        */
 
-      SFNT_Service  sfnt  = (SFNT_Service)face->sfnt;
+      SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
 
 
       if ( size && (size->root.metrics.x_ppem < 1 ||

src/truetype/ttgload.c

@@ -2802,7 +2802,9 @@
 #ifdef FT_CONFIG_OPTION_SVG
 
     /* check for OT-SVG */
-    if ( ( load_flags & FT_LOAD_COLOR ) && face->svg )
+    if ( ( load_flags & FT_LOAD_NO_SVG ) == 0 &&
+         ( load_flags & FT_LOAD_COLOR )       &&
+         face->svg                            )
     {
       SFNT_Service  sfnt = (SFNT_Service)face->sfnt;