From 1026587d631263942a4a5e6491fb944ffa2f46c6 Mon Sep 17 00:00:00 2001
From: Eduardo Cavazos <dharmatech@finkelstein.stackeffects.info>
Date: Fri, 11 Jul 2008 18:07:04 -0500
Subject: [PATCH] add math.geometry.rect

---
 extra/math/geometry/rect/rect.factor | 42 ++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 extra/math/geometry/rect/rect.factor

diff --git a/extra/math/geometry/rect/rect.factor b/extra/math/geometry/rect/rect.factor
new file mode 100644
index 0000000000..51f42c22ca
--- /dev/null
+++ b/extra/math/geometry/rect/rect.factor
@@ -0,0 +1,42 @@
+
+USING: kernel arrays math.vectors ;
+
+IN: math.geometry.rect
+
+TUPLE: rect { loc initial: { 0 0 } } { dim initial: { 0 0 } } ;
+
+: <zero-rect> ( -- rect ) rect new ;
+
+C: <rect> rect
+
+M: array rect-loc ;
+
+M: array rect-dim drop { 0 0 } ;
+
+: rect-bounds ( rect -- loc dim ) dup rect-loc swap rect-dim ;
+
+: rect-extent ( rect -- loc ext ) rect-bounds over v+ ;
+
+: 2rect-extent ( rect rect -- loc1 loc2 ext1 ext2 )
+    [ rect-extent ] bi@ swapd ;
+
+: <extent-rect> ( loc ext -- rect ) over [v-] <rect> ;
+
+: offset-rect ( rect loc -- newrect )
+    over rect-loc v+ swap rect-dim <rect> ;
+
+: (rect-intersect) ( rect rect -- array array )
+    2rect-extent vmin >r vmax r> ;
+
+: rect-intersect ( rect1 rect2 -- newrect )
+    (rect-intersect) <extent-rect> ;
+
+: intersects? ( rect/point rect -- ? )
+    (rect-intersect) [v-] { 0 0 } = ;
+
+: (rect-union) ( rect rect -- array array )
+    2rect-extent vmax >r vmin r> ;
+
+: rect-union ( rect1 rect2 -- newrect )
+    (rect-union) <extent-rect> ;
+