slightly explanatory comment for crossfading

git-svn-id: svn://localhost/ardour2/branches/3.0@12099 d708f5d6-7413-0410-9779-e7cbd77b26cf

diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index e4a7504ec17a3dbef49b95973fbf0039ccf821a0..8992f8ccca8da847036925504804aa78d2e908a8 100644 (file)
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -531,7 +531,12 @@ AudioRegion::_read_at (const SourceList& srcs, framecnt_t limit,
        }
 
 
-       /* APPLY FADES TO THE DATA IN mixdown_buffer AND MIX THE RESULTS INTO buf */
+       /* APPLY FADES TO THE DATA IN mixdown_buffer AND MIX THE RESULTS INTO
+        * buf. The key things to realize here: (1) the fade being applied is
+        * (as of April 26th 2012) just the inverse of the fade in curve (2) 
+        * "buf" contains data from lower regions already. So this operation
+        * fades out the existing material.
+        */
 
        if (fade_in_limit != 0) {
                _fade_in->curve().get_vector (internal_offset, internal_offset + fade_in_limit, gain_buffer, fade_in_limit);