1 files changed, 127 insertions, 0 deletions
diff --git a/src/base/ftadvanc.c b/src/base/ftadvanc.c
new file mode 100644
index 0000000..626a0cf
--- /dev/null
+++ b/src/base/ftadvanc.c
@@ -0,0 +1,127 @@
+#include <ft2build.h>
+#include FT_ADVANCES_H
+#include FT_INTERNAL_OBJECTS_H
+
+  static FT_Error
+  _ft_face_scale_advances( FT_Face    face,
+                           FT_Fixed*  advances,
+                           FT_UInt    count,
+                           FT_UInt    flags )
+  {
+    FT_Fixed  scale;
+    FT_UInt   nn;
+
+    if ( (flags & FT_LOAD_NO_SCALE) )
+      return FT_Err_Ok;
+
+    if ( face->size == NULL )
+      return FT_Err_Invalid_Size_Handle;
+
+    if ( !(flags & FT_LOAD_VERTICAL_LAYOUT) )
+      scale = face->size->metrics.x_scale;
+    else
+      scale = face->size->metrics.y_scale;
+
+    /* this must be the same computation than to get linearHori/VertAdvance
+     * (see FT_Load_Glyph() implementation in src/base/ftobjs.c */
+    for (nn = 0; nn < count; nn++)
+      advances[nn] = FT_MulDiv( advances[nn], scale, 64 );
+
+    return 0;
+  }
+
+
+/* at the moment, we can perform fast advance retrieval only in
+   the following cases:
+
+       - unscaled load
+       - unhinted load
+       - light-hinted load
+ */
+#define  LOAD_ADVANCE_FAST_CHECK(flags)    \
+    (((flags & (FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING)) != 0) || \
+     FT_LOAD_TARGET_MODE(flags) == FT_RENDER_MODE_LIGHT)
+
+  FT_EXPORT_DEF(FT_Error)
+  FT_Get_Advance( FT_Face    face,
+                  FT_UInt    gindex,
+                  FT_UInt    flags,
+                  FT_Fixed  *padvance )
+  {
+    FT_Face_GetAdvancesFunc  func;
+
+    if ( !face )
+      return FT_Err_Invalid_Face_Handle;
+
+    if (gindex >= (FT_UInt) face->num_glyphs )
+      return FT_Err_Invalid_Glyph_Index;
+
+    func = face->driver->clazz->get_advances;
+    if (func != NULL && LOAD_ADVANCE_FAST_CHECK(flags))
+    {
+      FT_Error  error;
+
+      error = func( face, gindex, 1, flags, padvance );
+      if (!error)
+        return _ft_face_scale_advances( face, padvance, 1, flags );
+
+      if (error != FT_Err_Unimplemented_Feature)
+        return error;
+    }
+
+    return FT_Get_Advances( face, gindex, 1, flags, padvance );
+  }
+
+
+  FT_EXPORT_DEF(FT_Error)
+  FT_Get_Advances( FT_Face    face,
+                   FT_UInt    start,
+                   FT_UInt    count,
+                   FT_UInt    flags,
+                   FT_Fixed  *padvances )
+  {
+    FT_Face_GetAdvancesFunc  func;
+    FT_UInt                  num, end, nn;
+    FT_Error                 error = 0;
+
+    if ( !face )
+      return FT_Err_Invalid_Face_Handle;
+
+    num = (FT_UInt) face->num_glyphs;
+    end = start + count;
+    if (start >= num || end < start || end > num)
+      return FT_Err_Invalid_Glyph_Index;
+
+    if (count == 0)
+        return FT_Err_Ok;
+
+    func = face->driver->clazz->get_advances;
+    if (func != NULL && LOAD_ADVANCE_FAST_CHECK(flags))
+    {
+      error = func( face, start, count, flags, padvances );
+      if (!error) goto Exit;
+
+      if (error != FT_Err_Unimplemented_Feature)
+        return error;
+    }
+
+    error = 0;
+
+    if ((flags & FT_ADVANCE_FLAG_FAST_ONLY) != 0)
+      return FT_Err_Unimplemented_Feature;
+
+    flags |= FT_LOAD_ADVANCE_ONLY;
+    for (nn = 0; nn < count; nn++)
+    {
+      error = FT_Load_Glyph( face, start+nn, flags );
+      if (error) break;
+
+      padvances[nn] = (flags & FT_LOAD_VERTICAL_LAYOUT)
+                    ? face->glyph->advance.x
+                    : face->glyph->advance.y;
+    }
+    if (error) return error;
+
+  Exit:
+    return _ft_face_scale_advances( face, padvances, count, flags );
+  }