From 1063d02f94d3a2f72065ab0b3ebac598137ea8db Mon Sep 17 00:00:00 2001
From: erg <devnull@localhost>
Date: Thu, 20 Apr 2006 21:22:16 +0000
Subject: [PATCH] Add ptToLine2 function returning the squared distance of a
 point to a line.

---
 lib/common/geom.c      | 11 +++++++++++
 lib/common/geomprocs.h |  1 +
 2 files changed, 12 insertions(+)

diff --git a/lib/common/geom.c b/lib/common/geom.c
index 91d5d04fb..d362f0cd2 100644
--- a/lib/common/geom.c
+++ b/lib/common/geom.c
@@ -503,3 +503,14 @@ box flip_rec_box(box b, point p)
     rv.UR.y += p.y;
     return rv;
 }
+
+/* ptToLine2:
+ * Return distance from point p to line a-b squared.
+ */
+double ptToLine2 (pointf a, pointf b, pointf p)
+{
+  double dx = b.x-a.x;
+  double dy = b.y-a.y;
+  double a2 = (p.y-a.y)*dx - (p.x-a.x)*dy;
+  return (a2*a2) / (dx*dx + dy*dy);
+}
diff --git a/lib/common/geomprocs.h b/lib/common/geomprocs.h
index 1f780a6d3..65fa3c914 100644
--- a/lib/common/geomprocs.h
+++ b/lib/common/geomprocs.h
@@ -48,6 +48,7 @@ extern bool box_contains(box, box);
 extern bool boxf_contains(boxf, boxf);
 extern box flip_rec_box(box b, point p);
 
+extern double ptToLine2 (pointf l1, pointf l2, pointf p);
 extern int lineToBox(pointf p1, pointf p2, boxf b);
 
 extern point ccwrotatep(point p, int ccwrot);
-- 
2.40.0