Refactor track features to bitflags

This is purely an internal refactor.
With the existing and currently planned boolean
features, a bit flag will scale better.

4 files changed, 27 insertions, 11 deletions

diff --git a/libass/ass.c b/libass/ass.c
index 8581141..79a3532 100644
--- a/libass/ass.c
+++ b/libass/ass.c
@@ -1535,17 +1535,33 @@ fail:
 
 int ass_track_set_feature(ASS_Track *track, ASS_Feature feature, int enable)
 {
-    switch (feature) {
-    case ASS_FEATURE_INCOMPATIBLE_EXTENSIONS:
-        //-fallthrough
+    if (feature >= sizeof(track->parser_priv->feature_flags) * CHAR_BIT || feature < 0)
+        return -1;
+
+    // all supported non-meta features
+    static const uint32_t supported =
 #ifdef USE_FRIBIDI_EX_API
-    case ASS_FEATURE_BIDI_BRACKETS:
-        track->parser_priv->bidi_brackets = !!enable;
+        FEATURE_MASK(ASS_FEATURE_BIDI_BRACKETS) |
 #endif
-        return 0;
+        0;
+    uint32_t requested = 0;
+
+    switch (feature) {
+    case ASS_FEATURE_INCOMPATIBLE_EXTENSIONS:
+        requested = supported;
+        break;
     default:
-        return -1;
+        if (!(FEATURE_MASK(feature) & supported))
+            return -1;
+        requested = FEATURE_MASK(feature);
     }
+
+    if (enable)
+        track->parser_priv->feature_flags |= requested;
+    else
+        track->parser_priv->feature_flags &= ~requested;
+
+    return 0;
 }
 
 /**
diff --git a/libass/ass_priv.h b/libass/ass_priv.h
index cd9447a..43a89c8 100644
--- a/libass/ass_priv.h
+++ b/libass/ass_priv.h
@@ -61,9 +61,7 @@ struct parser_priv {
     // tracks [Script Info] headers set by the script
     uint32_t header_flags;
 
-#ifdef USE_FRIBIDI_EX_API
-    bool bidi_brackets;
-#endif
+    uint32_t feature_flags;
 };
 
 #endif /* LIBASS_PRIV_H */
diff --git a/libass/ass_render.c b/libass/ass_render.c
index 770bf95..6991881 100644
--- a/libass/ass_render.c
+++ b/libass/ass_render.c
@@ -2883,7 +2883,7 @@ ass_start_frame(ASS_Renderer *render_priv, ASS_Track *track,
     ass_shaper_set_level(render_priv->shaper, render_priv->settings.shaper);
 #ifdef USE_FRIBIDI_EX_API
     ass_shaper_set_bidi_brackets(render_priv->shaper,
-            track->parser_priv->bidi_brackets);
+            track->parser_priv->feature_flags & FEATURE_MASK(ASS_FEATURE_BIDI_BRACKETS));
 #endif
 
     // PAR correction
diff --git a/libass/ass_utils.h b/libass/ass_utils.h
index 5418ee6..baee383 100644
--- a/libass/ass_utils.h
+++ b/libass/ass_utils.h
@@ -48,6 +48,8 @@
 
 #define ASS_PI 3.14159265358979323846
 
+#define FEATURE_MASK(feat) (((uint32_t) 1) << (feat))
+
 #if (defined(__i386__) || defined(__x86_64__)) && CONFIG_ASM
 int has_sse2(void);
 int has_avx(void);