From f24611980cab484148e5f50ea0916ba1a7e1ccb6 Mon Sep 17 00:00:00 2001
From: llyyr <llyyr.public@gmail.com>
Date: Mon, 14 Apr 2025 07:08:26 +0530
Subject: [PATCH] sub/osd: add osd-shaper and set it to simple by default

This is a change in default for libass with harfbuzz enabled, previously
it would choose the best available shaper.

Harfbuzz isn't really needed for mpv's OSD and it comes with a
significant performance penalty, so use simple instead
---
 DOCS/interface-changes/osd-cache-opts.txt | 1 +
 DOCS/man/options.rst                      | 4 ++++
 options/options.c                         | 1 +
 options/options.h                         | 1 +
 sub/osd_libass.c                          | 1 +
 5 files changed, 8 insertions(+)

diff --git a/DOCS/interface-changes/osd-cache-opts.txt b/DOCS/interface-changes/osd-cache-opts.txt
index 3b82453e25..acfab38395 100644
--- a/DOCS/interface-changes/osd-cache-opts.txt
+++ b/DOCS/interface-changes/osd-cache-opts.txt
@@ -3,3 +3,4 @@ add `--osd-glyph-limit`
 add `--osd-bitmap-max-size`
 add `--sub-glyph-limit`
 add `--sub-bitmap-max-size`
+add `--osd-shaper`
diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index e051700fbb..112867f211 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -4814,6 +4814,10 @@ OSD
     Set the delay for automatic pruning of events from memory in libass.
     Disabled by default. See also ``--sub-ass-prune-delay``.
 
+``--osd-shaper=<simple|complex>``
+    Set the text layout engine used by libass for the OSD. Default: simple.
+    See also ``--sub-shaper``
+
 Screenshot
 ----------
 
diff --git a/options/options.c b/options/options.c
index cfa790d2fd..4ec4ad6e9a 100644
--- a/options/options.c
+++ b/options/options.c
@@ -414,6 +414,7 @@ const struct m_sub_options mp_osd_render_sub_opts = {
         {"osd-prune-delay", OPT_DOUBLE(osd_ass_prune_delay), M_RANGE(-1.0, 10000.0)},
         {"osd-glyph-limit", OPT_INT(osd_glyph_limit)},
         {"osd-bitmap-max-size", OPT_INT(osd_bitmap_max_size)},
+        {"osd-shaper", OPT_CHOICE(osd_shaper, {"simple", 0}, {"complex", 1})},
         {0}
     },
     .size = sizeof(OPT_BASE_STRUCT),
diff --git a/options/options.h b/options/options.h
index faaa711814..3fd01545fd 100644
--- a/options/options.h
+++ b/options/options.h
@@ -151,6 +151,7 @@ struct mp_osd_render_opts {
     double osd_ass_prune_delay;
     int osd_glyph_limit;
     int osd_bitmap_max_size;
+    int osd_shaper;
 };
 
 typedef struct MPOpts {
diff --git a/sub/osd_libass.c b/sub/osd_libass.c
index 0131d138d4..126426c692 100644
--- a/sub/osd_libass.c
+++ b/sub/osd_libass.c
@@ -128,6 +128,7 @@ static void create_ass_track(struct osd_state *osd, struct osd_object *obj,
     track->WrapStyle = 1; // end-of-line wrapping instead of smart wrapping
     track->Kerning = true;
     track->ScaledBorderAndShadow = true;
+    ass_set_shaper(ass->render, opts->osd_shaper);
 #if LIBASS_VERSION >= 0x01600010
     ass_track_set_feature(track, ASS_FEATURE_WRAP_UNICODE, 1);
 #endif