+ inline hb_position_t get_x_delta (hb_font_t *font) const
+ { return get_delta (font->x_ppem, font->x_scale); }
+
+ inline hb_position_t get_y_delta (hb_font_t *font) const
+ { return get_delta (font->y_ppem, font->y_scale); }
+
+ inline int get_delta (unsigned int ppem, int scale) const
+ {
+ if (!ppem) return 0;
+
+ int pixels = get_delta_pixels (ppem);
+
+ if (!pixels) return 0;
+
+ return pixels * (int64_t) scale / ppem;
+ }
+
+
+ inline int get_delta_pixels (unsigned int ppem_size) const