AOO410/main/basegfx/source/curve/b2dbeziertools.cxx

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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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
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 * 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/curve/b2dbeziertools.hxx>
#include <basegfx/curve/b2dcubicbezier.hxx>
#include <algorithm>

//////////////////////////////////////////////////////////////////////////////

namespace basegfx
{
	B2DCubicBezierHelper::B2DCubicBezierHelper(const B2DCubicBezier& rBase, sal_uInt32 nDivisions)
	:	maLengthArray(),
		mnEdgeCount(0)
	{
		const bool bIsBezier(rBase.isBezier());

		if(bIsBezier)
		{
			// check nDivisions; at least one is needed, but also prevent too big values
			if(nDivisions < 1)
			{
				nDivisions = 1;
			}
			else if(nDivisions > 1000)
			{
				nDivisions = 1000;
			}

			// set nEdgeCount
			mnEdgeCount = nDivisions + 1;

			// fill in maLengthArray
			maLengthArray.clear();
			maLengthArray.reserve(mnEdgeCount);
			B2DPoint aCurrent(rBase.getStartPoint());
			double fLength(0.0);

			for(sal_uInt32 a(1);;)
			{
				const B2DPoint aNext(rBase.interpolatePoint((double)a / (double)mnEdgeCount));
				const B2DVector aEdge(aNext - aCurrent);

				fLength += aEdge.getLength();
				maLengthArray.push_back(fLength);

				if(++a < mnEdgeCount)
				{
					aCurrent = aNext;
				}
				else
				{
					const B2DPoint aLastNext(rBase.getEndPoint());
					const B2DVector aLastEdge(aLastNext - aNext);

					fLength += aLastEdge.getLength();
					maLengthArray.push_back(fLength);
					break;
				}
			}
		}
		else
		{
			maLengthArray.clear();
			maLengthArray.push_back(rBase.getEdgeLength());
			mnEdgeCount = 1;
		}
	}

	double B2DCubicBezierHelper::distanceToRelative(double fDistance) const
	{
		if(fDistance <= 0.0)
		{
			return 0.0;
		}

		const double fLength(getLength());

		if(fTools::moreOrEqual(fDistance, fLength))
		{
			return 1.0;
		}

		// fDistance is in ]0.0 .. fLength[

		if(1 == mnEdgeCount)
		{
			// not a bezier, linear edge
			return fDistance / fLength;
		}
		
		// it is a bezier
		::std::vector< double >::const_iterator aIter = ::std::lower_bound(maLengthArray.begin(), maLengthArray.end(), fDistance);
		const sal_uInt32 nIndex(aIter - maLengthArray.begin());
		const double fHighBound(maLengthArray[nIndex]);
		const double fLowBound(nIndex ?  maLengthArray[nIndex - 1] : 0.0);
		const double fLinearInterpolatedLength((fDistance - fLowBound) / (fHighBound - fLowBound));

		return (static_cast< double >(nIndex) + fLinearInterpolatedLength) / static_cast< double >(mnEdgeCount);
	}

	double B2DCubicBezierHelper::relativeToDistance(double fRelative) const
	{
		if(fRelative <= 0.0)
		{
			return 0.0;
		}

		const double fLength(getLength());

		if(fTools::moreOrEqual(fRelative, 1.0))
		{
			return fLength;
		}

		// fRelative is in ]0.0 .. 1.0[

		if(1 == mnEdgeCount)
		{
			// not a bezier, linear edge
			return fRelative * fLength;
		}

		// fRelative is in ]0.0 .. 1.0[
		const double fIndex(fRelative * static_cast< double >(mnEdgeCount));
		double fIntIndex;
		const double fFractIndex(modf(fIndex, &fIntIndex));
		const sal_uInt32 nIntIndex(static_cast< sal_uInt32 >(fIntIndex));
		const double fStartDistance(nIntIndex ? maLengthArray[nIntIndex - 1] : 0.0);

		return fStartDistance + ((maLengthArray[nIntIndex] - fStartDistance) * fFractIndex);
	}
} // end of namespace basegfx

//////////////////////////////////////////////////////////////////////////////

// eof