From 3e088dc4e59714a7d150043e58de627d015b8051 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Thu, 19 Mar 2020 12:58:23 +0100
Subject: API: clarify how new fields can be added to public types

This just gives a minor hint that all fields are frozen, but that the
size of the structs are not part of the ABI.

Most importantly, ASS_Style and ASS_Event are completely ABI-frozen,
because ASS_Track has the "styles" and "events" arrays.
---
 libass/ass.h       | 2 ++
 libass/ass_types.h | 3 +++
 2 files changed, 5 insertions(+)

(limited to 'libass')

diff --git a/libass/ass.h b/libass/ass.h
index cad25ae..78951a9 100644
--- a/libass/ass.h
+++ b/libass/ass.h
@@ -56,6 +56,7 @@ typedef struct ass_image {
         IMAGE_TYPE_SHADOW
     } type;
 
+    // New fields can be added here in new ABI-compatible library releases.
 } ASS_Image;
 
 /*
@@ -170,6 +171,7 @@ typedef enum {
      * On dialogue events override: Justify
      */
     ASS_OVERRIDE_BIT_JUSTIFY = 1 << 10,
+    // New enum values can be added here in new ABI-compatible library releases.
 } ASS_OverrideBits;
 
 /**
diff --git a/libass/ass_types.h b/libass/ass_types.h
index 88951a7..caa90aa 100644
--- a/libass/ass_types.h
+++ b/libass/ass_types.h
@@ -166,6 +166,7 @@ typedef enum ASS_YCbCrMatrix {
     YCBCR_SMPTE240M_PC,
     YCBCR_FCC_TV,
     YCBCR_FCC_PC
+    // New enum values can be added here in new ABI-compatible library releases.
 } ASS_YCbCrMatrix;
 
 /*
@@ -205,6 +206,8 @@ typedef struct ass_track {
 
     ASS_Library *library;
     ASS_ParserPriv *parser_priv;
+
+    // New fields can be added here in new ABI-compatible library releases.
 } ASS_Track;
 
 #endif /* LIBASS_TYPES_H */
-- 
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