Commit LivePathEffect branch to trunk!

(disabled extension/internal/bitmap/*.* in build.xml to fix compilation)

(bzr r3472)

1 files changed, 79 insertions, 0 deletions

diff --git a/src/2geom/utils.h b/src/2geom/utils.h
new file mode 100644
index 000000000..a2f906ff4
--- /dev/null
+++ b/src/2geom/utils.h
@@ -0,0 +1,79 @@
+#ifndef MATH_UTILS_HEADER
+#define MATH_UTILS_HEADER
+
+/** Various utility functions.
+ *
+ * Copyright 2006 Michael G. Sloan <mgsloan@gmail.com>
+ *
+ * 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 <cmath>
+#include <stdexcept>
+
+class NotImplemented : public std::logic_error {
+public:
+  NotImplemented() : std::logic_error("method not implemented") {}
+};
+
+/** Sign function - indicates the sign of a numeric type.  -1 indicates negative, 1 indicates
+ *  positive, and 0 indicates, well, 0.  Mathsy people will know this is basically the derivative
+ *  of abs, except for the fact that it is defined on 0.
+ */
+template <class T> inline int sgn(const T& x) {return (x < 0 ? -1 : (x > 0 ? 1 : 0) );}
+
+template <class T> inline T sqr(const T& x) {return x * x;}
+template <class T> inline T cube(const T& x) {return x * x * x;}
+
+/** Between function - returns true if a number x is within a range. The values delimiting the
+ *  range and the number must have the same type.
+ */
+template <class T> inline const T& between (const T& min, const T& max, const T& x)
+    { return min < x && max > x; }
+
+/** Returns x rounded to the nearest integer.  It is unspecified what happens
+ *  if x is half way between two integers: we may in future use rint/round
+ *  on platforms that have them.
+ */
+inline double round(double const x) { return std::floor(x + .5); }
+
+/** Returns x rounded to the nearest \a places decimal places.
+
+    Implemented in terms of round, i.e. we make no guarantees as to what happens if x is
+    half way between two rounded numbers.
+    
+    Note: places is the number of decimal places without using scientific (e) notation, not the
+    number of significant figures.  This function may not be suitable for values of x whose
+    magnitude is so far from 1 that one would want to use scientific (e) notation.
+
+    places may be negative: e.g. places = -2 means rounding to a multiple of .01
+**/
+inline double decimal_round(double const x, int const places) {
+    //TODO: possibly implement with modulus instead?
+    double const multiplier = std::pow(10.0, places);
+    return round( x * multiplier ) / multiplier;
+}
+
+#endif