From f256f4d0e9babb6afd1a5ee3405e70da02c2e9e7 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 5 Aug 2013 16:38:05 +1000
Subject: [PATCH] Add a point constrain method to region

Force a point to not exceed the region boundaries.
---
 region.cpp | 10 +++++++++-
 region.hpp |  3 ++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/region.cpp b/region.cpp
index b9a70ce0..1ce9f143 100644
--- a/region.cpp
+++ b/region.cpp
@@ -136,9 +136,17 @@ region<T>::overlaps (const region<T> &rhs) const {
 
 
 //-----------------------------------------------------------------------------
+template <typename T>
+void
+region<T>::constrain (point2 &p) const {
+    p.x = std::min (std::max (static_cast<T> (p.x), x), x + w);
+    p.y = std::min (std::max (static_cast<T> (p.y), y), y + h);
+}
+
+
 template <typename T>
 point2
-region<T>::constrain (const point2 &p) const {
+region<T>::constrained (const point2 &p) const {
     point2 v;
     v.x = std::min (std::max (static_cast<T> (p.x), x), x + w);
     v.y = std::min (std::max (static_cast<T> (p.y), y), y + h);
diff --git a/region.hpp b/region.hpp
index 0036255a..905969a5 100644
--- a/region.hpp
+++ b/region.hpp
@@ -57,7 +57,8 @@ namespace util {
         bool contains (const point2&) const; // exclusive of borders
         bool overlaps (const region<T>&) const; // exclusive of borders
 
-        point2 constrain (const point2&) const;
+        void constrain (point2&) const;
+        point2 constrained (const point2&) const;
 
         region overlap (const region<T>&) const;