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diff --git a/src/gui/general/Spline.cpp b/src/gui/general/Spline.cpp
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+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Rosegarden
+    A MIDI and audio sequencer and musical notation editor.
+ 
+    This program is Copyright 2000-2008
+        Guillaume Laurent   <glaurent@telegraph-road.org>,
+        Chris Cannam        <cannam@all-day-breakfast.com>,
+        Richard Bown        <richard.bown@ferventsoftware.com>
+ 
+    The moral rights of Guillaume Laurent, Chris Cannam, and Richard
+    Bown to claim authorship of this work have been asserted.
+ 
+    Other copyrights also apply to some parts of this work.  Please
+    see the AUTHORS file and individual file headers for details.
+ 
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+
+#include "Spline.h"
+
+#include <qpoint.h>
+
+
+namespace Rosegarden
+{
+
+Spline::PointList *
+
+Spline::calculate(const QPoint &s, const QPoint &f, const PointList &cp,
+                  QPoint &topLeft, QPoint &bottomRight)
+{
+    if (cp.size() < 2)
+        return 0;
+
+    int i;
+    PointList *acc = new PointList();
+    QPoint p(s);
+
+    topLeft = bottomRight = QPoint(0, 0);
+
+    for (i = 1; i < cp.size(); ++i) {
+
+        QPoint c(cp[i - 1]);
+
+        int x = (c.x() + cp[i].x()) / 2;
+        int y = (c.y() + cp[i].y()) / 2;
+        QPoint n(x, y);
+
+        calculateSegment(acc, p, n, c, topLeft, bottomRight);
+
+        p = n;
+    }
+
+    calculateSegment(acc, p, f, cp[i - 1], topLeft, bottomRight);
+
+    return acc;
+}
+
+void
+Spline::calculateSegment(PointList *acc,
+                         const QPoint &s, const QPoint &f, const QPoint &c,
+                         QPoint &topLeft, QPoint &bottomRight)
+{
+    int x, y, n;
+
+    x = c.x() - s.x();
+    y = c.y() - s.y();
+
+    if (x < 0)
+        x = -x;
+    if (y < 0)
+        y = -y;
+    if (x > y)
+        n = x;
+    else
+        n = y;
+
+    x = f.x() - c.x();
+    y = f.y() - c.y();
+
+    if (x < 0)
+        x = -x;
+    if (y < 0)
+        y = -y;
+    if (x > y)
+        n += x;
+    else
+        n += y;
+
+    calculateSegmentSub(acc, s, f, c, n, topLeft, bottomRight);
+}
+
+void
+Spline::calculateSegmentSub(PointList *acc,
+                            const QPoint &s, const QPoint &f, const QPoint &c,
+                            int n, QPoint &topLeft, QPoint &bottomRight)
+{
+    double ax = (double)(f.x() + s.x() - 2 * c.x()) / (double)n;
+    double ay = (double)(f.y() + s.y() - 2 * c.y()) / (double)n;
+
+    double bx = 2.0 * (double)(c.x() - s.x());
+    double by = 2.0 * (double)(c.y() - s.y());
+
+    for (int m = 0; m <= n; ++m) {
+
+        int x = s.x() + (int)((m * ((double)m * ax + bx)) / n);
+        int y = s.y() + (int)((m * ((double)m * ay + by)) / n);
+
+        if (x < topLeft.x())
+            topLeft.setX(x);
+        if (y < topLeft.y())
+            topLeft.setY(y);
+
+        if (x > bottomRight.x())
+            bottomRight.setX(x);
+        if (y > bottomRight.y())
+            bottomRight.setY(y);
+
+        acc->push_back(QPoint(x, y));
+    }
+}
+
+}