diff --git a/src/libnr/nr-rect.h b/src/libnr/nr-rect.h
index dd7caa897ea100c4a59704df33943926033ada89..46aff13f4fa938212f39df8654abeaacd1cdcaf5 100644 (file)
--- a/src/libnr/nr-rect.h
+++ b/src/libnr/nr-rect.h
/** 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]. A rectangle may be empty, in the
+ * sense of having zero area, but it will always contain at least one
+ * point. Infinities are also permitted.
+ */
class Rect {
public:
Rect() : _min(-_inf(), -_inf()), _max(_inf(), _inf()) {}
/** returns the midpoint of this rect. */
Point midpoint() const;
- /** does this rectangle have zero area? */
- bool isEmpty() const {
- return isEmpty<X>() || isEmpty<Y>();
+ /** True iff either width or height is less than \a epsilon. */
+ bool isEmpty(double epsilon=1e-6) const {
+ return isEmpty<X>(epsilon) || isEmpty<Y>(epsilon);
}
bool intersects(Rect const &r) const {
_max[NR::Y] += by;
}
- /** Returns the set of points shared by both rectangles. */
- static Maybe<Rect> intersection(Maybe<Rect> const &a, Maybe<Rect> const &b);
-
- /** Returns the smallest rectangle that encloses both rectangles. */
- static Maybe<Rect> union_bounds(Maybe<Rect> const &a, Maybe<Rect> const &b)
- {
- if (!a) {
- return b;
- } else if (!b) {
- return a;
- } else {
- return union_bounds(*a, *b);
- }
- }
- static Rect union_bounds(Maybe<Rect> const &a, Rect const &b) {
- if (a) {
- return union_bounds(*a, b);
- } else {
- return b;
- }
- }
- static Rect union_bounds(Rect const &a, Maybe<Rect> const &b) {
- if (b) {
- return union_bounds(a, *b);
- } else {
- return a;
- }
- }
- static Rect union_bounds(Rect const &a, Rect const &b);
+ void growBy (gdouble by);
/** Scales the rect by s, with origin at 0, 0 */
inline Rect operator*(double const s) const {
friend inline std::ostream &operator<<(std::ostream &out_file, NR::Rect const &in_rect);
private:
+ Rect(Nothing) : _min(1, 1), _max(-1, -1) {}
+
static double _inf() {
return std::numeric_limits<double>::infinity();
}
return _max[axis] - _min[axis];
}
- template <Dim2 axis>
- bool isEmpty() const {
- return !( _min[axis] < _max[axis] );
+ template <NR::Dim2 axis>
+ bool isEmpty(double epsilon) const {
+ return extent<axis>() < epsilon;
}
template <Dim2 axis>
Point _min, _max;
- /* evil, but temporary */
- friend class Maybe<Rect>;
+ friend class MaybeStorage<Rect>;
+ friend Maybe<Rect> intersection(Maybe<Rect> const &, Maybe<Rect> const &);
+ friend Rect union_bounds(Rect const &, Rect const &);
};
+template <>
+class MaybeStorage<Rect> {
+public:
+ MaybeStorage() : _rect(Nothing()) {}
+ MaybeStorage(Rect const &rect) : _rect(rect) {}
+
+ bool is_nothing() const {
+ return _rect._min[X] > _rect._max[X];
+ }
+ Rect const &value() const { return _rect; }
+ Rect &value() { return _rect; }
+
+private:
+ Rect _rect;
+};
+
+/** Returns the set of points shared by both rectangles. */
+Maybe<Rect> intersection(Maybe<Rect> const & a, Maybe<Rect> const & b);
+
+/** Returns the smallest rectangle that encloses both rectangles. */
+Rect union_bounds(Rect const &a, Rect const &b);
+inline Rect union_bounds(Maybe<Rect> const & a, Rect const &b) {
+ if (a) {
+ return union_bounds(*a, b);
+ } else {
+ return b;
+ }
+}
+inline Rect union_bounds(Rect const &a, Maybe<Rect> const & b) {
+ if (b) {
+ return union_bounds(a, *b);
+ } else {
+ return a;
+ }
+}
+inline Maybe<Rect> union_bounds(Maybe<Rect> const & a, Maybe<Rect> const & b)
+{
+ if (!a) {
+ return b;
+ } else if (!b) {
+ return a;
+ } else {
+ return union_bounds(*a, *b);
+ }
+}
+
/** A function to print out the rectange if sent to an output
stream. */
inline std::ostream
#define nr_rect_d_set_empty(r) (*(r) = NR_RECT_EMPTY)
#define nr_rect_l_set_empty(r) (*(r) = NR_RECT_L_EMPTY)
+/** "Empty" here includes the case of zero width or zero height. */
#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))