ban empty rectangles entirely and remove isEmpty test

(bzr r2606)

2 files changed, 13 insertions, 14 deletions

diff --git a/src/libnr/nr-rect.cpp b/src/libnr/nr-rect.cpp
index 2d4629d42..a9487045a 100644
--- a/src/libnr/nr-rect.cpp
+++ b/src/libnr/nr-rect.cpp
@@ -244,7 +244,12 @@ namespace NR {
 
 Rect::Rect(const Point &p0, const Point &p1)
 : _min(std::min(p0[X], p1[X]), std::min(p0[Y], p1[Y])),
-  _max(std::max(p0[X], p1[X]), std::max(p0[Y], p1[Y])) {}
+  _max(std::max(p0[X], p1[X]), std::max(p0[Y], p1[Y]))
+{
+    if ( _min[X] == _max[X] || _min[Y] == _max[Y] ) {
+        throw EmptyRectangle();
+    }
+}
 
 /** returns the four corners of the rectangle in the correct winding order */
 Point Rect::corner(unsigned i) const {
diff --git a/src/libnr/nr-rect.h b/src/libnr/nr-rect.h
index b632261aa..6ae1e4e99 100644
--- a/src/libnr/nr-rect.h
+++ b/src/libnr/nr-rect.h
@@ -28,12 +28,16 @@
 namespace NR {
     struct Matrix;
 
+class EmptyRectangle : public std::logic_error {
+public:
+    EmptyRectangle() : logic_error("Attempt to create empty rectangle") {}
+};
+
 /** A rectangle is always aligned to the X and Y axis.  This means it
  * can be defined using only 4 coordinates, and determining
  * intersection is very efficient.  The points inside a rectangle are
- * min[dim] <= _pt[dim] <= max[dim].  Emptiness, however, is defined
- * as having zero area, meaning an empty rectangle may still contain
- * points.  Infinities are also permitted. */
+ * min[dim] <= _pt[dim] <= max[dim].  Emptiness, in the sense of having
+ * a zero area, is not permitted.  Infinities are, however. */
 class Rect {
 public:
     Rect() : _min(-_inf(), -_inf()), _max(_inf(), _inf()) {}
@@ -52,11 +56,6 @@ public:
     /** returns the midpoint of this rect. */
     Point midpoint() const;
 
-    /** does this rectangle have zero area? */
-    bool isEmpty() const {
-        return isEmpty<X>() || isEmpty<Y>();
-    }
-
     bool intersects(Rect const &r) const {
         return intersects<X>(r) && intersects<Y>(r);
     }
@@ -154,11 +153,6 @@ private:
     }
 
     template <Dim2 axis>
-    bool isEmpty() const {
-        return !( _min[axis] < _max[axis] );
-    }
-
-    template <Dim2 axis>
     bool intersects(Rect const &r) const {
         return _max[axis] >= r._min[axis] && _min[axis] <= r._max[axis];
     }