moving trunk for module inkscape

(bzr r1)

1 files changed, 74 insertions, 0 deletions

diff --git a/src/libnr/nr-point-fns.cpp b/src/libnr/nr-point-fns.cpp
new file mode 100644
index 000000000..a92c2b00b
--- /dev/null
+++ b/src/libnr/nr-point-fns.cpp
@@ -0,0 +1,74 @@
+#include <libnr/nr-point-fns.h>
+#include <isnan.h>
+
+using NR::Point;
+
+/** Compute the L infinity, or maximum, norm of \a p. */
+NR::Coord NR::LInfty(Point const &p) {
+    NR::Coord const a(fabs(p[0]));
+    NR::Coord const b(fabs(p[1]));
+    return ( a < b || isNaN(b)
+             ? b
+             : a );
+}
+
+/** Returns true iff p is a zero vector, i.e.\ Point(0, 0).
+ *
+ *  (NaN is considered non-zero.)
+ */
+bool
+NR::is_zero(Point const &p)
+{
+    return ( p[0] == 0 &&
+             p[1] == 0   );
+}
+
+bool
+NR::is_unit_vector(Point const &p)
+{
+    return fabs(1.0 - L2(p)) <= 1e-4;
+    /* The tolerance of 1e-4 is somewhat arbitrary.  NR::Point::normalize is believed to return
+       points well within this tolerance.  I'm not aware of any callers that want a small
+       tolerance; most callers would be ok with a tolerance of 0.25. */
+}
+
+NR::Coord NR::atan2(Point const p) {
+    return std::atan2(p[NR::Y], p[NR::X]);
+}
+
+/** Returns a version of \a a scaled to be a unit vector (within rounding error).
+ *
+ *  The current version tries to handle infinite coordinates gracefully,
+ *  but it's not clear that any callers need that.
+ *
+ *  \pre a != Point(0, 0).
+ *  \pre Neither coordinate is NaN.
+ *  \post L2(ret) very near 1.0.
+ */
+Point NR::unit_vector(Point const &a)
+{
+    Point ret(a);
+    ret.normalize();
+    return ret;
+}
+
+NR::Point abs(NR::Point const &b)
+{
+    NR::Point ret;
+    for ( int i = 0 ; i < 2 ; i++ ) {
+        ret[i] = fabs(b[i]);
+    }
+    return ret;
+}
+
+
+/*
+  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 :