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authorKurt Zenker <kz@openoffice.org>2005-01-13 17:00:43 +0000
committerKurt Zenker <kz@openoffice.org>2005-01-13 17:00:43 +0000
commitd58f8be98ecfccd6f27af1146ab1fe0c1bd9cb61 (patch)
tree266e7497757d1a91ce24c2cd46a831c91107fcc4 /basegfx/source/tools
parent851f3e270ba408c864657f7de63177dd139f1a6b (diff)
INTEGRATION: CWS presperf01 (1.1.2); FILE ADDED
2004/12/17 22:35:22 thb 1.1.2.1: #i36093# Initial revision
Diffstat (limited to 'basegfx/source/tools')
-rw-r--r--basegfx/source/tools/liangbarsky.cxx163
1 files changed, 163 insertions, 0 deletions
diff --git a/basegfx/source/tools/liangbarsky.cxx b/basegfx/source/tools/liangbarsky.cxx
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index 000000000000..b4fd9b47be33
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+++ b/basegfx/source/tools/liangbarsky.cxx
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+/*************************************************************************
+ *
+ * $RCSfile: liangbarsky.cxx,v $
+ *
+ * $Revision: 1.2 $
+ *
+ * last change: $Author: kz $ $Date: 2005-01-13 18:00:43 $
+ *
+ * The Contents of this file are made available subject to the terms of
+ * either of the following licenses
+ *
+ * - GNU Lesser General Public License Version 2.1
+ * - Sun Industry Standards Source License Version 1.1
+ *
+ * Sun Microsystems Inc., October, 2000
+ *
+ * GNU Lesser General Public License Version 2.1
+ * =============================================
+ * Copyright 2000 by Sun Microsystems, Inc.
+ * 901 San Antonio Road, Palo Alto, CA 94303, USA
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software Foundation.
+ *
+ * This library 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 for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ *
+ * Sun Industry Standards Source License Version 1.1
+ * =================================================
+ * The contents of this file are subject to the Sun Industry Standards
+ * Source License Version 1.1 (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.openoffice.org/license.html.
+ *
+ * Software provided under this License is provided on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
+ * MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
+ * See the License for the specific provisions governing your rights and
+ * obligations concerning the Software.
+ *
+ * The Initial Developer of the Original Code is: Sun Microsystems, Inc.
+ *
+ * Copyright: 2000 by Sun Microsystems, Inc.
+ *
+ * All Rights Reserved.
+ *
+ * Contributor(s): _______________________________________
+ *
+ *
+ ************************************************************************/
+
+#include "basegfx/tools/tools.hxx"
+#include "basegfx/numeric/ftools.hxx"
+#include "basegfx/range/b2drange.hxx"
+
+
+namespace basegfx
+{
+ namespace tools
+ {
+ namespace
+ {
+ // see Foley/vanDam, pp. 122 for the Liang-Barsky line
+ // clipping algorithm
+ inline bool liangBarskyClipT( double nDenom,
+ double nNumerator,
+ double& io_rTE,
+ double& io_rTL )
+ {
+ double t;
+ if( nDenom > 0 )
+ {
+ t = nNumerator / nDenom;
+ if( t > io_rTL )
+ return false;
+ else if( t > io_rTE )
+ io_rTE = t;
+ }
+ else if( nDenom < 0 )
+ {
+ t = nNumerator / nDenom;
+ if( t < io_rTE )
+ return false;
+ else
+ io_rTL = t;
+ }
+ else if( nNumerator > 0 )
+ {
+ return false;
+ }
+
+ return true;
+ }
+ }
+
+ // see Foley/vanDam, pp. 122 for the Liang-Barsky line
+ // clipping algorithm
+ bool liangBarskyClip2D( ::basegfx::B2DPoint& io_rStart,
+ ::basegfx::B2DPoint& io_rEnd,
+ const ::basegfx::B2DRange& rClipRect )
+ {
+ const double nDX( io_rEnd.getX() - io_rStart.getX() );
+ const double nDY( io_rEnd.getY() - io_rStart.getY() );
+
+ if( ::basegfx::fTools::equalZero( nDX ) &&
+ ::basegfx::fTools::equalZero( nDY ) )
+ {
+ return rClipRect.isInside( io_rStart );
+ }
+ else
+ {
+ double nTE( 0.0 );
+ double nTL( 1.0 );
+ if( liangBarskyClipT(nDX, rClipRect.getMinX() - io_rStart.getX(),
+ nTE, nTL ) ) // inside wrt. left edge
+ {
+ if( liangBarskyClipT(-nDX, io_rStart.getX() - rClipRect.getMaxX(),
+ nTE, nTL ) ) // inside wrt. right edge
+ {
+ if( liangBarskyClipT(nDY, rClipRect.getMinY() - io_rStart.getY(),
+ nTE, nTL ) ) // inside wrt. bottom edge
+ {
+ if( liangBarskyClipT(-nDY, io_rStart.getY() - rClipRect.getMaxY(),
+ nTE, nTL ) ) // inside wrt. top edge
+ {
+ // compute actual intersection points,
+ // if nTL has changed
+ if( nTL < 1.0 )
+ {
+ io_rEnd.setX( io_rStart.getX() + nTL*nDX );
+ io_rEnd.setY( io_rStart.getY() + nTL*nDY );
+ }
+
+ // compute actual intersection points,
+ // if nTE has changed
+ if( nTE > 0.0 )
+ {
+ io_rStart.setX( io_rStart.getX() + nTE*nDX );
+ io_rStart.setY( io_rStart.getY() + nTE*nDY );
+ }
+
+ // line is (at least partially) visible
+ return true;
+ }
+ }
+ }
+ }
+ }
+
+ return false;
+ }
+ }
+}