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+/*************************************************************************
+ *
+ * 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 );
+ }
+ }
+}