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-rw-r--r--basegfx/source/numeric/ftools.cxx135
1 files changed, 135 insertions, 0 deletions
diff --git a/basegfx/source/numeric/ftools.cxx b/basegfx/source/numeric/ftools.cxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright
+ * ownership. The ASF licenses this file to you under the Apache
+ * License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <basegfx/numeric/ftools.hxx>
+
+namespace basegfx
+{
+ double snapToNearestMultiple(double v, const double fStep)
+ {
+ if(fTools::equalZero(fStep))
+ {
+ // with a zero step, all snaps to 0.0
+ return 0.0;
+ }
+ else
+ {
+ const double fHalfStep(fStep * 0.5);
+ const double fChange(fHalfStep - fmod(v + fHalfStep, fStep));
+
+ if(basegfx::fTools::equal(fabs(v), fabs(fChange)))
+ {
+ return 0.0;
+ }
+ else
+ {
+ return v + fChange;
+ }
+ }
+ }
+
+ double snapToZeroRange(double v, double fWidth)
+ {
+ if(fTools::equalZero(fWidth))
+ {
+ // with no range all snaps to range bound
+ return 0.0;
+ }
+ else
+ {
+ if(v < 0.0 || v > fWidth)
+ {
+ double fRetval(fmod(v, fWidth));
+
+ if(fRetval < 0.0)
+ {
+ fRetval += fWidth;
+ }
+
+ return fRetval;
+ }
+ else
+ {
+ return v;
+ }
+ }
+ }
+
+ double snapToRange(double v, double fLow, double fHigh)
+ {
+ if(fTools::equal(fLow, fHigh))
+ {
+ // with no range all snaps to range bound
+ return 0.0;
+ }
+ else
+ {
+ if(fLow > fHigh)
+ {
+ // correct range order. Evtl. assert this (?)
+ std::swap(fLow, fHigh);
+ }
+
+ if(v < fLow || v > fHigh)
+ {
+ return snapToZeroRange(v - fLow, fHigh - fLow) + fLow;
+ }
+ else
+ {
+ return v;
+ }
+ }
+ }
+
+ double normalizeToRange(double v, const double fRange)
+ {
+ if(fTools::lessOrEqual(fRange, 0.0))
+ {
+ // with a zero (or less) range, all normalizes to 0.0
+ return 0.0;
+ }
+
+ const bool bNegative(fTools::less(v, 0.0));
+
+ if(bNegative)
+ {
+ if(fTools::moreOrEqual(v, -fRange))
+ {
+ // in range [-fRange, 0.0[, shift one step
+ return v + fRange;
+ }
+
+ // re-calculate
+ return v - (floor(v/fRange)*fRange);
+ }
+ else
+ {
+ if(fTools::less(v, fRange))
+ {
+ // already in range [0.0, fRange[, nothing to do
+ return v;
+ }
+
+ // re-calculate
+ return v - (floor(v/fRange)*fRange);
+ }
+ }
+} // end of namespace basegfx
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */