[buffer] Add debugging, aka, message, API
Currently just announces lookup applications. Message-API *will* change.
hb-shape / hb-view are updated to print-out messages to stder if --debug
is specified.
diff --git a/src/hb-buffer.h b/src/hb-buffer.h
index d3a2512..a28d47f 100644
--- a/src/hb-buffer.h
+++ b/src/hb-buffer.h
@@ -373,6 +373,21 @@
hb_buffer_serialize_format_t format);
+/*
+ * Debugging.
+ */
+
+typedef hb_bool_t (*hb_buffer_message_func_t) (hb_buffer_t *buffer,
+ hb_font_t *font,
+ const char *message,
+ void *user_data);
+
+HB_EXTERN void
+hb_buffer_set_message_func (hb_buffer_t *buffer,
+ hb_buffer_message_func_t func,
+ void *user_data, hb_destroy_func_t destroy);
+
+
HB_END_DECLS
#endif /* HB_BUFFER_H */
