diff options
Diffstat (limited to 'basegfx/source/numeric')
-rw-r--r-- | basegfx/source/numeric/ftools.cxx | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/basegfx/source/numeric/ftools.cxx b/basegfx/source/numeric/ftools.cxx new file mode 100644 index 0000000000..246d8d548a --- /dev/null +++ b/basegfx/source/numeric/ftools.cxx @@ -0,0 +1,135 @@ +/* -*- 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: */ |