2a99d78cddf4b7de673435f911262ee25b36c238
braney
  Sun Feb 12 14:14:18 2023 -0800
ongoing work on snake display for chains and psls

diff --git src/hg/hgTracks/snake.h src/hg/hgTracks/snake.h
index bc9e365..bfb7cc6 100644
--- src/hg/hgTracks/snake.h
+++ src/hg/hgTracks/snake.h
@@ -1,5 +1,28 @@
+/* snake.h - data structures and routines for drawing snakes */
+
+/* Copyright (C) 2023 The Regents of the University of California 
+ * See kent/LICENSE or http://genome.ucsc.edu/license/ for licensing information. */
+
+#ifndef SNAKE_H
 
 struct snakeInfo
 {
 int maxLevel;
 } ;
+
+struct snakeFeature
+    {
+    struct snakeFeature *next;
+    int start, end;			/* Start/end in browser coordinates. */
+    int qStart, qEnd;			/* query start/end */
+    int level;				/* level in snake */
+    int orientation;			/* strand... -1 is '-', 1 is '+' */
+    boolean drawn;			/* did we draw this feature? */
+    char *qSequence;			/* may have sequence, or NULL */
+    char *tSequence;			/* may have sequence, or NULL */
+    char *qName;			/* chrom name on other species */
+    unsigned pixX1, pixX2;              /* pixel coordinates within window */
+    };
+
+void maybeLoadSnake(struct track *track);
+#endif /* SNAKE_H */