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Diffstat (limited to 'basegfx/source/tools/tools.cxx')
-rw-r--r-- | basegfx/source/tools/tools.cxx | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/basegfx/source/tools/tools.cxx b/basegfx/source/tools/tools.cxx new file mode 100644 index 000000000000..d375f144169d --- /dev/null +++ b/basegfx/source/tools/tools.cxx @@ -0,0 +1,124 @@ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * This file is part of OpenOffice.org. + * + * OpenOffice.org is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 3 + * only, as published by the Free Software Foundation. + * + * OpenOffice.org is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License version 3 for more details + * (a copy is included in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU Lesser General Public License + * version 3 along with OpenOffice.org. If not, see + * <http://www.openoffice.org/license.html> + * for a copy of the LGPLv3 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 ); + } + } +} |