Re: master f34f474e386: Properly instruct compound glyphs with compound components

[Stefan Kangas]

Po Lu via Mailing list for Emacs changes <emacs-diffs@gnu.org> writes:

> branch: master
> commit f34f474e386b662114e6ee4ebd8c37f4cb66db71
> Author: Po Lu <luangruo@yahoo.com>
> Commit: Po Lu <luangruo@yahoo.com>
>
>     Properly instruct compound glyphs with compound components
>
>     * src/sfnt.c (sfnt_interpret_compound_glyph_2): Don't grow the
>     compound decomposition context for saving compound points into,
>     since the space for them already exists.
> ---
>  src/sfnt.c | 34 ++++++++++------------------------
>  1 file changed, 10 insertions(+), 24 deletions(-)
>
> diff --git a/src/sfnt.c b/src/sfnt.c
> index 62ed27b4311..1397e341aa8 100644
> --- a/src/sfnt.c
> +++ b/src/sfnt.c
> @@ -12618,15 +12618,14 @@ sfnt_interpret_compound_glyph_2 (struct sfnt_glyph 
> *glyph,
>    struct sfnt_interpreter_zone *zone;
>    struct sfnt_interpreter_zone *volatile preserved_zone;
>    volatile bool zone_was_allocated;
> -  int rc;
>    sfnt_f26dot6 *x_base, *y_base;
> -  size_t *contour_base;
> -  unsigned char *flags_base;
>
> -  /* Figure out how many points and contours there are to
> -     instruct.  */
> +  /* Figure out how many points and contours there are to instruct.  A
> +     minimum of two points must be present, to wit the origin and
> +     advance phantom points.  */

Does "to wit" here mean "to know"?  If so, could we install something
like the below?

Merriam Webster tells me that "wit" used as a verb is "archaic", so I'd
propose avoiding that word completely.

diff --git a/src/sfnt.c b/src/sfnt.c
index 1397e341aa8..f30279fd283 100644
--- a/src/sfnt.c
+++ b/src/sfnt.c
@@ -12621,7 +12621,7 @@ sfnt_interpret_compound_glyph_2 (struct
sfnt_glyph *glyph,
   sfnt_f26dot6 *x_base, *y_base;

   /* Figure out how many points and contours there are to instruct.  A
-     minimum of two points must be present, to wit the origin and
+     minimum of two points must be present, to know the origin and
      advance phantom points.  */
   num_points = context->num_points - base_index;
   num_contours = context->num_end_points - base_contour;


>    num_points = context->num_points - base_index;
>    num_contours = context->num_end_points - base_contour;
> +  assert (num_points >= 2);
>
>    /* Nothing to instruct! */
>    if (!num_points && !num_contours)
> @@ -12740,27 +12739,14 @@ sfnt_interpret_compound_glyph_2 (struct sfnt_glyph 
> *glyph,
>        context->y_coordinates[base_index + i] = zone->y_current[i];
>      }
>
> -  /* Grow various arrays to fit the phantom points.  */
> -  rc = sfnt_expand_compound_glyph_context (context, 0, 2,
> -                                        &x_base, &y_base,
> -                                        &flags_base,
> -                                        &contour_base);
> -
> -  if (rc)
> -    {
> -      if (zone_was_allocated)
> -     xfree (zone);
> -
> -      return "Failed to expand arrays for phantom points";
> -    }
> -
> -  /* Copy over the phantom points.  */
> +  /* Return the phantom points after instructing completes to the
> +     context's coordinate arrays.  */
> +  x_base    = &context->x_coordinates[i - 2];
> +  y_base    = &context->y_coordinates[i - 2];
>    x_base[0] = zone->x_current[num_points - 2];
>    x_base[1] = zone->x_current[num_points - 1];
>    y_base[0] = zone->y_current[num_points - 2];
>    y_base[1] = zone->y_current[num_points - 1];
> -  flags_base[0] = zone->flags[num_points - 2];
> -  flags_base[1] = zone->flags[num_points - 1];
>
>    /* Free the zone if needed.  */
>    if (zone_was_allocated)
> @@ -20573,8 +20559,8 @@ main (int argc, char **argv)
>        return 1;
>      }
>
> -#define FANCY_PPEM 12
> -#define EASY_PPEM  12
> +#define FANCY_PPEM 14
> +#define EASY_PPEM  14
>
>    interpreter = NULL;
>    head = sfnt_read_head_table (fd, font);