[Commit] tess ChangeLog,1.6,1.7 bentley.5c,1.7,1.8

[Carl Worth]

Committed by: cworth

Update of /local/src/CVS/tess
In directory home.keithp.com:/tmp/cvs-serv3342

Modified Files:
	ChangeLog bentley.5c 
Log Message:

        * bentley.5c (bentley_ottman): Fix insert_event_if to use
        intersect_segments rather than a custom, (and inadequate in the
        case of horizontal lines) check for containment of the
        intersection within the segments. Add note on future slope
        comparison optimization.


Index: ChangeLog
===================================================================
RCS file: /local/src/CVS/tess/ChangeLog,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -d -r1.6 -r1.7
--- ChangeLog	7 Jul 2004 19:26:59 -0000	1.6
+++ ChangeLog	7 Jul 2004 19:34:41 -0000	1.7
@@ -1,5 +1,13 @@
 2004-07-07  Carl Worth  <cworth at isi.edu>
 
+	* bentley.5c (bentley_ottman): Fix insert_event_if to use
+	intersect_segments rather than a custom, (and inadequate in the
+	case of horizontal lines) check for containment of the
+	intersection within the segments. Add note on future slope
+	comparison optimization.
+
+2004-07-07  Carl Worth  <cworth at isi.edu>
+
 	* bentley.5c (bentley_ottman): Cosmetic changes: Rename
 	insert_event_if_intersect to
 	insert_event_if_intersect_below_current_y and use more descriptive

Index: bentley.5c
===================================================================
RCS file: /local/src/CVS/tess/bentley.5c,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -d -r1.7 -r1.8
--- bentley.5c	7 Jul 2004 19:26:59 -0000	1.7
+++ bentley.5c	7 Jul 2004 19:34:41 -0000	1.8
@@ -364,17 +364,29 @@
 	if (left == Sortlist::List.nil || right == Sortlist::List.nil)
 	    return;
 
+/* XXX: Hobby suggests an initial slope comparison before the
+ * intersection test, which is faster for the common case. But I don't
+ * see an easy way to make this work with horizontal
+ * edges. Fortunately, we plan to get rid of those.
+ *
+ * When this test is enabled, we can drop the comparison between
+ * intersection.c and current_y below.
+ */
+/*
+	if (slope_greater (*left.elt, *right.elt))
+	    return;
+*/
+
 	RationalPoint intersection;
 	try {
-	    intersection = intersect_lines (*left.elt, *right.elt);
+	    intersection = intersect_segments (*left.elt, *right.elt);
 	} catch parallel () {
 	    return;
+	} catch no_intersection () {
+	    return;
 	}
 
-	if (intersection.y > current_y
-	    && intersection.y < left.elt->bottom.y 
-	    && intersection.y < right.elt->bottom.y
-	    )
+	if (intersection.y > current_y)
 	{
 	    Sortlist::insert (&event_queue,
 			      (EventPtr.elt) &(Event) {