c3bb4207fb2a58064b937ba9fef1cc11852f7576
hiram
  Wed Mar 25 10:48:49 2026 -0700
allow trackDb entry to override the in-code defaults of the gcOnFly track refs #35958

diff --git src/hg/hgTracks/hgTracks.h src/hg/hgTracks/hgTracks.h
index 06e87f5e59c..e3781b69ebe 100644
--- src/hg/hgTracks/hgTracks.h
+++ src/hg/hgTracks/hgTracks.h
@@ -1202,30 +1202,36 @@
 /* Return linked features from range of table with the scores scaled appropriately */
 
 void ctWigLoadItems(struct track *tg);
 /*	load custom wiggle track data	*/
 void wigLoadItems(struct track *tg);
 /*	load wiggle track data from database	*/
 void wigMethods(struct track *track, struct trackDb *tdb,
                                 int wordCount, char *words[]);
 /* Set up wig pointers and do some other precalculations on a wig type track. */
 void bedGraphMethods(struct track *track, struct trackDb *tdb,
 	int wordCount, char *words[]);
 void bigWigMethods(struct track *track, struct trackDb *tdb,
 	int wordCount, char *words[]);
 /* Make track group for wig - wiggle tracks. */
 
+void gc5BaseOnTheFlyMethods(struct track *tg, struct cart *cart);
+/* Install on-the-fly GC computation methods on a track that was
+ *     loaded from trackDb.  Overrides the bigWig loadItems/loadPreDraw
+ *     so data is computed from genome sequence instead of read from a file.
+ */
+
 struct track *gc5BaseOnTheFlyTg(struct cart *cart);
 /* Create an on-the-fly GC percent track computed directly from
  *     genome sequence.  Default visibility is dense; the cart
  *     override happens later in the getTrackList() visibility loop.
  */
 
 void mathWigMethods(struct track *track, struct trackDb *tdb, 
 	int wordCount, char *words[]);
 /* mathWig load and draw methods. */
 
 void bigRmskMethods(struct track *track, struct trackDb *tdb,
                                 int wordCount, char *words[]);
 /* Set up bigRmsk methods. */
 
 void commonBigBedMethods(struct track *track, struct trackDb *tdb,