diff options
| author | wm4 <wm4@nowhere> | 2013-09-24 22:28:35 +0200 |
|---|---|---|
| committer | wm4 <wm4@nowhere> | 2013-09-24 22:28:35 +0200 |
| commit | 05eb520f431e73c2ad19a8e0261f35d396545cf9 (patch) | |
| tree | f3a2bff8aecde35d967105f15680753183e9f4db | |
| parent | 7a2596b0e3a644f927046774dd748d5ff8e1b0c6 (diff) | |
| download | libass-05eb520f431e73c2ad19a8e0261f35d396545cf9.tar.bz2 libass-05eb520f431e73c2ad19a8e0261f35d396545cf9.tar.xz | |
Restore hinting
This was broken since commit f780146. For reasons why, read the commit
message of that commit. To make it short, we set the font size to
something large and constant (256), and scale the font outlines returned
by freetype to the size we need in order to get smooth animation and
accurate positioning.
Of course, this obviously breaks hinting. Fix hinting by not using the
hack mentioned above if hinting enabled.
To mitigate the issues caused by freetype grid fitting and extremely
bad ASS scripts (such as setting font size to very small values and
scaling them up with \fscx/y), we still adjust the font size such that
the font is never scaled in Y direction (only in X direction, because
the \fscx/y tags can change aspect ratio).
Also see google code issue #46.
| -rw-r--r-- | libass/ass.h | 7 | ||||
| -rw-r--r-- | libass/ass_render.c | 13 |
2 files changed, 17 insertions, 3 deletions
diff --git a/libass/ass.h b/libass/ass.h index 0778a5c..cb85a2c 100644 --- a/libass/ass.h +++ b/libass/ass.h @@ -56,6 +56,13 @@ typedef struct ass_image { /* * Hinting type. (see ass_set_hinting below) * + * Setting hinting to anything but ASS_HINTING_NONE will put libass in a mode + * that reduces compatibility with vsfilter and many ASS scripts. The main + * problem is that hinting conflicts with smooth scaling, which precludes + * animations and precise positioning. + * + * In other words, enabling hinting might break some scripts severely. + * * FreeType's native hinter is still buggy sometimes and it is recommended * to use the light autohinter, ASS_HINTING_LIGHT, instead. For best * compatibility with problematic fonts, disable hinting. diff --git a/libass/ass_render.c b/libass/ass_render.c index e592548..45d88bb 100644 --- a/libass/ass_render.c +++ b/libass/ass_render.c @@ -1097,9 +1097,16 @@ get_outline_glyph(ASS_Renderer *priv, GlyphInfo *info) v.desc = drawing->desc; key.u.drawing.text = strdup(drawing->text); } else { - // arbitrary, not too small to prevent grid fitting rounding effects - // XXX: this is a rather crude hack - const double ft_size = 256.0; + double ft_size; + if (priv->settings.hinting == ASS_HINTING_NONE) { + // arbitrary, not too small to prevent grid fitting rounding effects + // XXX: this is a rather crude hack + ft_size = 256.0; + } else { + // If hinting is enabled, we want to pass the real font size + // to freetype. Normalize scale_y to 1.0. + ft_size = info->scale_y * info->font_size; + } ass_face_set_size(info->font->faces[info->face_index], ft_size); ass_font_set_transform(info->font, info->scale_x * info->font_size / ft_size, |