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diff --git a/src/libnr/nr-rect.h b/src/libnr/nr-rect.h
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+#ifndef LIBNR_NR_RECT_H_SEEN
+#define LIBNR_NR_RECT_H_SEEN
+
+/** \file
+ * Definitions of NRRect and NR::Rect types, and some associated functions \& macros.
+ */
+/*
+ * Authors:
+ * Lauris Kaplinski <lauris@kaplinski.com>
+ * Nathan Hurst <njh@mail.csse.monash.edu.au>
+ * MenTaLguY <mental@rydia.net>
+ *
+ * This code is in public domain
+ */
+
+
+#include <stdexcept>
+
+#include "libnr/nr-values.h"
+#include <libnr/nr-coord.h>
+#include <libnr/nr-i-coord.h>
+#include <libnr/nr-dim2.h>
+#include <libnr/nr-point.h>
+#include <libnr/nr-maybe.h>
+#include <libnr/nr-point-matrix-ops.h>
+
+struct NRMatrix;
+namespace NR {
+ struct Matrix;
+}
+
+/* NULL rect is infinite */
+
+struct NRRect {
+ NR::Coord x0, y0, x1, y1;
+};
+
+inline bool empty(NRRect const &r)
+{
+ return ( ( r.x0 > r.x1 ) ||
+ ( r.y0 > r.y1 ) );
+}
+
+#define nr_rect_d_set_empty(r) (*(r) = NR_RECT_EMPTY)
+#define nr_rect_l_set_empty(r) (*(r) = NR_RECT_L_EMPTY)
+
+#define nr_rect_d_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
+#define nr_rect_l_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
+
+#define nr_rect_d_test_intersect(r0,r1) \
+ (!nr_rect_d_test_empty(r0) && !nr_rect_d_test_empty(r1) && \
+ !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
+#define nr_rect_l_test_intersect(r0,r1) \
+ (!nr_rect_l_test_empty(r0) && !nr_rect_l_test_empty(r1) && \
+ !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
+
+#define nr_rect_d_point_d_test_inside(r,p) ((p) && (!(r) || (!NR_RECT_DF_TEST_EMPTY(r) && NR_RECT_DF_POINT_DF_TEST_INSIDE(r,p))))
+
+/* NULL values are OK for r0 and r1, but not for d */
+NRRect *nr_rect_d_intersect(NRRect *d, NRRect const *r0, NRRect const *r1);
+NRRectL *nr_rect_l_intersect(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
+
+NRRect *nr_rect_d_union(NRRect *d, NRRect const *r0, NRRect const *r1);
+NRRectL *nr_rect_l_union(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
+
+NRRect *nr_rect_union_pt(NRRect *dst, NR::Point const &p);
+NRRect *nr_rect_d_union_xy(NRRect *d, NR::Coord x, NR::Coord y);
+NRRectL *nr_rect_l_union_xy(NRRectL *d, NR::ICoord x, NR::ICoord y);
+
+NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NR::Matrix const &m);
+NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NRMatrix const *m);
+
+namespace NR {
+
+/** 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. */
+class Rect {
+public:
+ Rect(NRRect const &r) : _min(r.x0, r.y0), _max(r.x1, r.y1) {}
+ Rect(Rect const &r) : _min(r._min), _max(r._max) {}
+ Rect(Point const &p0, Point const &p1);
+
+ Point const &min() const { return _min; }
+ Point const &max() const { return _max; }
+
+ /** returns the four corners of the rectangle in order
+ * (clockwise if +Y is up, anticlockwise if +Y is down) */
+ Point corner(unsigned i) const;
+
+ /** returns a vector from min to max. */
+ Point dimensions() const;
+
+ /** 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);
+ }
+ bool contains(Rect const &r) const {
+ return contains<X>(r) && contains<Y>(r);
+ }
+ bool contains(Point const &p) const {
+ return contains<X>(p) && contains<Y>(p);
+ }
+
+ double area() const {
+ return extent<X>() * extent<Y>();
+ }
+
+ double maxExtent() const {
+ return MAX(extent<X>(), extent<Y>());
+ }
+
+ double extent(Dim2 const axis) const {
+ switch (axis) {
+ case X: return extent<X>();
+ case Y: return extent<Y>();
+ default: g_error("invalid axis value %d", (int) axis); return 0;
+ };
+ }
+
+ double extent(unsigned i) const throw(std::out_of_range) {
+ switch (i) {
+ case 0: return extent<X>();
+ case 1: return extent<Y>();
+ default: throw std::out_of_range("Dimension out of range");
+ };
+ }
+
+ /**
+ \brief Remove some precision from the Rect
+ \param places The number of decimal places left in the end
+
+ This function just calls round on the \c _min and \c _max points.
+ */
+ inline void round(int places = 0) {
+ _min.round(places);
+ _max.round(places);
+ return;
+ }
+
+ /** Translates the rectangle by p. */
+ void offset(Point p);
+
+ /** Makes this rectangle large enough to include the point p. */
+ void expandTo(Point p);
+
+ /** Makes this rectangle large enough to include the rectangle r. */
+ void expandTo(Rect const &r);
+
+ inline void move_left (gdouble by) {
+ _min[NR::X] += by;
+ }
+ inline void move_right (gdouble by) {
+ _max[NR::X] += by;
+ }
+ inline void move_top (gdouble by) {
+ _min[NR::Y] += by;
+ }
+ inline void move_bottom (gdouble by) {
+ _max[NR::Y] += by;
+ }
+
+ /** Returns the set of points shared by both rectangles. */
+ static Maybe<Rect> intersection(Rect const &a, Rect const &b);
+
+ /** Returns the smallest rectangle that encloses both rectangles. */
+ static Rect union_bounds(Rect const &a, Rect const &b);
+
+ /** Scales the rect by s, with origin at 0, 0 */
+ inline Rect operator*(double const s) const {
+ return Rect(s * min(), s * max());
+ }
+
+ /** Transforms the rect by m. Note that it gives correct results only for scales and translates */
+ inline Rect operator*(Matrix const m) const {
+ return Rect(_min * m, _max * m);
+ }
+
+ inline bool operator==(Rect const &in_rect) {
+ return ((this->min() == in_rect.min()) && (this->max() == in_rect.max()));
+ }
+
+ friend inline std::ostream &operator<<(std::ostream &out_file, NR::Rect const &in_rect);
+
+private:
+ Rect() {}
+
+ template <NR::Dim2 axis>
+ double extent() const {
+ return _max[axis] - _min[axis];
+ }
+
+ 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];
+ }
+
+ template <Dim2 axis>
+ bool contains(Rect const &r) const {
+ return contains(r._min) && contains(r._max);
+ }
+
+ template <Dim2 axis>
+ bool contains(Point const &p) const {
+ return p[axis] >= _min[axis] && p[axis] <= _max[axis];
+ }
+
+ Point _min, _max;
+
+ /* evil, but temporary */
+ friend class Maybe<Rect>;
+};
+
+/** A function to print out the rectange if sent to an output
+ stream. */
+inline std::ostream
+&operator<<(std::ostream &out_file, NR::Rect const &in_rect)
+{
+ out_file << "Rectangle:\n";
+ out_file << "\tMin Point -> " << in_rect.min() << "\n";
+ out_file << "\tMax Point -> " << in_rect.max() << "\n";
+
+ return out_file;
+}
+
+} /* namespace NR */
+
+
+#endif /* !LIBNR_NR_RECT_H_SEEN */
+
+/*
+ Local Variables:
+ mode:c++
+ c-file-style:"stroustrup"
+ c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+ indent-tabs-mode:nil
+ fill-column:99
+ End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
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