ср, 15 янв. 2020 г. в 11:25, Robert Pluim <rpluim@gmail.com>:

> >>>>> On Wed, 15 Jan 2020 13:26:11 +0900, YAMAMOTO Mitsuharu <
> mituharu@math.s.chiba-u.ac.jp> said:
>
>     YAMAMOTO> 0xFFFFFFFF comes from FONT_INVALID_CODE.
> font->driver->text_extents
>     YAMAMOTO> shouldn't be called if font->font->driver->encode_char
> returns it.
>
>     YAMAMOTO> diff --git a/src/font.c b/src/font.c
>     YAMAMOTO> index 2b90903c90..03e6176220 100644
>     YAMAMOTO> --- a/src/font.c
>     YAMAMOTO> +++ b/src/font.c
>     YAMAMOTO> @@ -4420,15 +4420,19 @@ font_fill_lglyph_metrics
> (Lisp_Object glyph, Lisp_Object font_object)
>     YAMAMOTO>  {
>     YAMAMOTO>    struct font *font = XFONT_OBJECT (font_object);
>     YAMAMOTO>    unsigned code = font->driver->encode_char (font,
> LGLYPH_CHAR (glyph));
>     YAMAMOTO> -  struct font_metrics metrics;
>     YAMAMOTO> -
>     YAMAMOTO> -  LGLYPH_SET_CODE (glyph, code);
>     YAMAMOTO> -  font->driver->text_extents (font, &code, 1, &metrics);
>     YAMAMOTO> -  LGLYPH_SET_LBEARING (glyph, metrics.lbearing);
>     YAMAMOTO> -  LGLYPH_SET_RBEARING (glyph, metrics.rbearing);
>     YAMAMOTO> -  LGLYPH_SET_WIDTH (glyph, metrics.width);
>     YAMAMOTO> -  LGLYPH_SET_ASCENT (glyph, metrics.ascent);
>     YAMAMOTO> -  LGLYPH_SET_DESCENT (glyph, metrics.descent);
>     YAMAMOTO> +
>     YAMAMOTO> +  if (code != FONT_INVALID_CODE)
>     YAMAMOTO> +    {
>     YAMAMOTO> +      struct font_metrics metrics;
>     YAMAMOTO> +
>     YAMAMOTO> +      LGLYPH_SET_CODE (glyph, code);
>     YAMAMOTO> +      font->driver->text_extents (font, &code, 1, &metrics);
>     YAMAMOTO> +      LGLYPH_SET_LBEARING (glyph, metrics.lbearing);
>     YAMAMOTO> +      LGLYPH_SET_RBEARING (glyph, metrics.rbearing);
>     YAMAMOTO> +      LGLYPH_SET_WIDTH (glyph, metrics.width);
>     YAMAMOTO> +      LGLYPH_SET_ASCENT (glyph, metrics.ascent);
>     YAMAMOTO> +      LGLYPH_SET_DESCENT (glyph, metrics.descent);
>     YAMAMOTO> +    }
>     YAMAMOTO>  }
>
>
>     YAMAMOTO> But I'm not sure if it is ok to leave the code and
> metrics-related
>     YAMAMOTO> fields nil when encode_char returns FONT_INVALID_CODE.
> Handa-san?
>
> I donʼt know either, but your patch fixes the slowdown and Iʼve seen
> no negative effects yet.
>

Yeah, this patch fixes the slowdown!

-- 
lg