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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
* under the License.
*
*************************************************************/
// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_basegfx.hxx"
#include "basegfx/tools/tools.hxx"
#include "basegfx/range/b2drange.hxx"
#include <algorithm>
namespace basegfx
{
namespace tools
{
namespace
{
inline double distance( const double& nX,
const double& nY,
const ::basegfx::B2DVector& rNormal,
const double& nC )
{
return nX*rNormal.getX() + nY*rNormal.getY() - nC;
}
void moveLineOutsideRect( ::basegfx::B2DPoint& io_rStart,
::basegfx::B2DPoint& io_rEnd,
const ::basegfx::B2DVector& rMoveDirection,
const ::basegfx::B2DRange& rFitTarget )
{
// calc c for normal line form equation n x - c = 0
const double nC( rMoveDirection.scalar( io_rStart ) );
// calc maximum orthogonal distance for all four bound
// rect corners to the line
const double nMaxDistance( ::std::max(
0.0,
::std::max(
distance(rFitTarget.getMinX(),
rFitTarget.getMinY(),
rMoveDirection,
nC),
::std::max(
distance(rFitTarget.getMinX(),
rFitTarget.getMaxY(),
rMoveDirection,
nC),
::std::max(
distance(rFitTarget.getMaxX(),
rFitTarget.getMinY(),
rMoveDirection,
nC),
distance(rFitTarget.getMaxX(),
rFitTarget.getMaxY(),
rMoveDirection,
nC) ) ) ) ) );
// now move line points, such that the bound rect
// points are all either 'on' or on the negative side
// of the half-plane
io_rStart += nMaxDistance*rMoveDirection;
io_rEnd += nMaxDistance*rMoveDirection;
}
}
void infiniteLineFromParallelogram( ::basegfx::B2DPoint& io_rLeftTop,
::basegfx::B2DPoint& io_rLeftBottom,
::basegfx::B2DPoint& io_rRightTop,
::basegfx::B2DPoint& io_rRightBottom,
const ::basegfx::B2DRange& rFitTarget )
{
// For the top and bottom border line of the
// parallelogram, we determine the distance to all four
// corner points of the bound rect (tl, tr, bl, br). When
// using the unit normal form for lines (n x - c = 0), and
// choosing n to point 'outwards' the parallelogram, then
// all bound rect corner points having positive distance
// to the line lie outside the extended gradient rect, and
// thus, the corresponding border line must be moved the
// maximum distance outwards.
// don't use the top and bottom border line direction, and
// calculate the normal from them. Instead, use the
// vertical lines (lt - lb or rt - rb), as they more
// faithfully represent the direction of the
// to-be-generated infinite line
::basegfx::B2DVector aDirectionVertical( io_rLeftTop - io_rLeftBottom );
aDirectionVertical.normalize();
const ::basegfx::B2DVector aNormalTop( aDirectionVertical );
const ::basegfx::B2DVector aNormalBottom( -aDirectionVertical );
// now extend parallelogram, such that the bound rect
// point are included
moveLineOutsideRect( io_rLeftTop, io_rRightTop, aNormalTop, rFitTarget );
moveLineOutsideRect( io_rLeftBottom, io_rRightBottom, aNormalBottom, rFitTarget );
}
}
}
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