Adding upstream version 1.0.2.upstream/1.0.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 187 insertions, 0 deletions

diff --git a/src/2geom/curve.cpp b/src/2geom/curve.cpp
new file mode 100644
index 0000000..8ad0178
--- /dev/null
+++ b/src/2geom/curve.cpp
@@ -0,0 +1,187 @@
+/* Abstract curve type - implementation of default methods
+ *
+ * Authors:
+ *   MenTaLguY <mental@rydia.net>
+ *   Marco Cecchetti <mrcekets at gmail.com>
+ *   Krzysztof Kosiński <tweenk.pl@gmail.com>
+ * 
+ * Copyright 2007-2009 Authors
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ */
+
+#include <2geom/curve.h>
+#include <2geom/exception.h>
+#include <2geom/nearest-time.h>
+#include <2geom/sbasis-geometric.h>
+#include <2geom/sbasis-to-bezier.h>
+#include <2geom/ord.h>
+#include <2geom/path-sink.h>
+
+//#include <iostream>
+
+namespace Geom 
+{
+
+Coord Curve::nearestTime(Point const& p, Coord a, Coord b) const
+{
+    return nearest_time(p, toSBasis(), a, b);
+}
+
+std::vector<Coord> Curve::allNearestTimes(Point const& p, Coord from, Coord to) const
+{
+    return all_nearest_times(p, toSBasis(), from, to);
+}
+
+Coord Curve::length(Coord tolerance) const
+{
+    return ::Geom::length(toSBasis(), tolerance);
+}
+
+int Curve::winding(Point const &p) const
+{
+    try {
+        std::vector<Coord> ts = roots(p[Y], Y);
+        if(ts.empty()) return 0;
+        std::sort(ts.begin(), ts.end());
+
+        // skip endpoint roots when they are local maxima on the Y axis
+        // this follows the convention used in other winding routines,
+        // i.e. that the bottommost coordinate is not part of the shape
+        bool ignore_0 = unitTangentAt(0)[Y] <= 0;
+        bool ignore_1 = unitTangentAt(1)[Y] >= 0;
+
+        int wind = 0;
+        for (std::size_t i = 0; i < ts.size(); ++i) {
+            Coord t = ts[i];
+            //std::cout << t << std::endl;
+            if ((t == 0 && ignore_0) || (t == 1 && ignore_1)) continue;
+            if (valueAt(t, X) > p[X]) { // root is ray intersection
+                Point tangent = unitTangentAt(t);
+                if (tangent[Y] > 0) {
+                    // at the point of intersection, curve goes in +Y direction,
+                    // so it winds in the direction of positive angles
+                    ++wind;
+                } else if (tangent[Y] < 0) {
+                    --wind;
+                }
+            }
+        }
+        return wind;
+    } catch (InfiniteSolutions const &e) {
+        // this means we encountered a line segment exactly coincident with the point
+        // skip, since this will be taken care of by endpoint roots in other segments
+        return 0;
+    }
+}
+
+std::vector<CurveIntersection> Curve::intersect(Curve const &/*other*/, Coord /*eps*/) const
+{
+    // TODO: approximate as Bezier
+    THROW_NOTIMPLEMENTED();
+}
+
+std::vector<CurveIntersection> Curve::intersectSelf(Coord eps) const
+{
+    std::vector<CurveIntersection> result;
+    // Monotonic segments cannot have self-intersections.
+    // Thus, we can split the curve at roots and intersect the portions.
+    std::vector<Coord> splits;
+    std::unique_ptr<Curve> deriv(derivative());
+    splits = deriv->roots(0, X);
+    if (splits.empty()) {
+        return result;
+    }
+    deriv.reset();
+    splits.push_back(1.);
+
+    boost::ptr_vector<Curve> parts;
+    Coord previous = 0;
+    for (unsigned i = 0; i < splits.size(); ++i) {
+        if (splits[i] == 0.) continue;
+        parts.push_back(portion(previous, splits[i]));
+        previous = splits[i];
+    }
+
+    Coord prev_i = 0;
+    for (unsigned i = 0; i < parts.size()-1; ++i) {
+        Interval dom_i(prev_i, splits[i]);
+        prev_i = splits[i];
+
+        Coord prev_j = 0;
+        for (unsigned j = i+1; j < parts.size(); ++j) {
+            Interval dom_j(prev_j, splits[j]);
+            prev_j = splits[j];
+
+            std::vector<CurveIntersection> xs = parts[i].intersect(parts[j], eps);
+            for (unsigned k = 0; k < xs.size(); ++k) {
+                // to avoid duplicated intersections, skip values at exactly 1
+                if (xs[k].first == 1. || xs[k].second == 1.) continue;
+
+                Coord ti = dom_i.valueAt(xs[k].first);
+                Coord tj = dom_j.valueAt(xs[k].second);
+
+                CurveIntersection real(ti, tj, xs[k].point());
+                result.push_back(real);
+            }
+        }
+    }
+    return result;
+}
+
+Point Curve::unitTangentAt(Coord t, unsigned n) const
+{
+    std::vector<Point> derivs = pointAndDerivatives(t, n);
+    for (unsigned deriv_n = 1; deriv_n < derivs.size(); deriv_n++) {
+        Coord length = derivs[deriv_n].length();
+        if ( ! are_near(length, 0) ) {
+            // length of derivative is non-zero, so return unit vector
+            return derivs[deriv_n] / length;
+        }
+    }
+    return Point (0,0);
+};
+
+void Curve::feed(PathSink &sink, bool moveto_initial) const
+{
+    std::vector<Point> pts;
+    sbasis_to_bezier(pts, toSBasis(), 2); //TODO: use something better!
+    if (moveto_initial) {
+        sink.moveTo(initialPoint());
+    }
+    sink.curveTo(pts[0], pts[1], pts[2]);
+}
+
+} // namespace Geom
+
+/*
+  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:fileencoding=utf-8:textwidth=99 :