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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/.
*
*/
#include <basegfx/polygon/WaveLine.hxx>
#include <basegfx/point/b2dpoint.hxx>
namespace basegfx
{
BASEGFX_DLLPUBLIC B2DPolygon createWaveLinePolygon(basegfx::B2DRectangle const& rRectangle)
{
basegfx::B2DPolygon aPolygon;
double fWaveHeight = rRectangle.getHeight();
// Wavelength depends on the wave height so it looks nice
double fHalfWaveLength = fWaveHeight + 1.0;
double fWaveAmplitude = fWaveHeight / 2.0;
double fLastX = rRectangle.getMinX();
double fBaseY = rRectangle.getMinY() + fWaveAmplitude;
double fDirection = 1.0;
// In quadratic bezier the curve is 1/2 of the control height
// so we need to compensate for that.
constexpr double fHeightCompensation = 2.0;
aPolygon.append(basegfx::B2DPoint(fLastX, fBaseY));
for (double fI = fHalfWaveLength; fI <= rRectangle.getWidth(); fI += fHalfWaveLength)
{
basegfx::B2DPoint aPoint(fLastX + fHalfWaveLength, fBaseY);
basegfx::B2DPoint aControl(fLastX + (fHalfWaveLength / 2.0),
fBaseY + fDirection * fWaveAmplitude * fHeightCompensation);
aPolygon.appendQuadraticBezierSegment(aControl, aPoint);
fLastX = aPoint.getX(); // next iteration
fDirection *= -1.0; // fDirection iterates between 1 and -1
}
return aPolygon;
}
} // end of namespace basegfx
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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