xref: /aoo42x/main/basegfx/source/numeric/ftools.cxx (revision b056bc42)

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 *
 * 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
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_basegfx.hxx"
#include <basegfx/numeric/ftools.hxx>
#include <algorithm>

namespace basegfx
{
	// init static member of class fTools
	double ::basegfx::fTools::mfSmallValue = 0.000000001;

	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;
			}
		}
	}
} // end of namespace basegfx

// eof