strepsirrhini/office-gobmx
9
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Initial revision

Browse source
This commit is contained in:
Thorsten Behrens 2003-11-10 12:33:07 +00:00
parent fd56c146e7
commit fd1976f802
2 changed files with 347 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

131
basegfx/inc/basegfx/curve/b2dbeziertools.hxx Normal file
View file

@ -0,0 +1,131 @@
/*************************************************************************
*
* $RCSfile: b2dbeziertools.hxx,v $
*
* $Revision: 1.1 $
*
* last change: $Author: thb $ $Date: 2003-11-10 13:33:07 $
*
* 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): _______________________________________
*
*
************************************************************************/
#ifndef _BGFX_CURVE_B2DBEZIERTOOLS_HXX
#define _BGFX_CURVE_B2DBEZIERTOOLS_HXX
//////////////////////////////////////////////////////////////////////////////
namespace basegfx
{
namespace polygon
{
class B2DPolygon;
}
namespace curve
{
class B2DCubicBezier;
class B2DQuadraticBezier;
/** Subdivide given cubic bezier segment.
This function adaptively subdivides the given bezier
segment into as much straight line segments, such that the
maximal orthogonal distance from any of the segments to
the true curve is less than the given error value.
@param rPoly
Output polygon. The subdivided bezier segment is added to
this polygon via B2DPolygon::append().
@param rCurve
The cubic bezier curve to subdivide
@param distanceBounds
Bounds on the maximal distance of the approximation to the
true curve
@return the number of line segments created
*/
int adaptiveSubdivide( polygon::B2DPolygon& rPoly,
const B2DCubicBezier& rCurve,
double distanceBounds );
/** Subdivide given quadratic bezier segment.
This function adaptively subdivides the given bezier
segment into as much straight line segments, such that the
maximal orthogonal distance from any of the segments to
the true curve is less than the given error value.
@param rPoly
Output polygon. The subdivided bezier segment is added to
this polygon via B2DPolygon::append().
@param rCurve
The cubic bezier curve to subdivide
@param distanceBounds
Bounds on the maximal distance of the approximation to the
true curve
@return the number of line segments created
*/
int adaptiveSubdivide( polygon::B2DPolygon& rPoly,
const B2DQuadraticBezier& rCurve,
double distanceBounds );
}
}
#endif // _BGFX_CURVE_B2DBEZIERTOOLS_HXX2

216
basegfx/source/curve/b2dbeziertools.cxx Normal file
View file

@ -0,0 +1,216 @@
/*************************************************************************
*
* $RCSfile: b2dbeziertools.cxx,v $
*
* $Revision: 1.1 $
*
* last change: $Author: thb $ $Date: 2003-11-10 13:32:04 $
*
* 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 <limits>
#include <algorithm>
#include <basegfx/curve/b2dbeziertools.hxx>
#ifndef _BGFX_CURVE_B2DCUBICBEZIER_HXX
#include <basegfx/curve/b2dcubicbezier.hxx>
#endif
#ifndef _BGFX_CURVE_B2DQUADRATICBEZIER_HXX
#include <basegfx/curve/b2dquadraticbezier.hxx>
#endif
#ifndef _BGFX_POLYGON_B2DPOLYGON_HXX
#include <basegfx/polygon/b2dpolygon.hxx>
#endif
#ifndef _BGFX_POINT_B2DPOINT_HXX
#include <basegfx/point/b2dpoint.hxx>
#endif
namespace basegfx
{
namespace curve
{
namespace
{
/* Recursively subdivide cubic bezier curve via deCasteljau.
@param rPoly
Polygon to append generated points to
@param d2
Maximal squared difference of curve to a straight line
@param P*
Exactly four points, interpreted as support and control points of
a cubic bezier curve.
@param old_distance2
Last squared distance to line for this recursion
path. Used as an end condition, if it is no longer
improving.
@param recursionDepth
Depth of recursion. Used as a termination criterion, to
prevent endless looping.
*/
int ImplAdaptiveSubdivide( polygon::B2DPolygon& rPoly,
const double d2,
const double P1x, const double P1y,
const double P2x, const double P2y,
const double P3x, const double P3y,
const double P4x, const double P4y,
const double old_distance2,
int recursionDepth )
{
// Hard limit on recursion depth, empiric number.
enum {maxRecursionDepth=128};
// Perform bezier flatness test (lecture notes from R. Schaback,
// Mathematics of Computer-Aided Design, Uni Goettingen, 2000)
//
// ||P(t) - L(t)|| <= max ||b_j - b_0 - j/n(b_n - b_0)||
// 0<=j<=n
//
// What is calculated here is an upper bound to the distance from
// a line through b_0 and b_3 (P1 and P4 in our notation) and the
// curve. We can drop 0 and n from the running indices, since the
// argument of max becomes zero for those cases.
const double fJ1x( P2x - P1x - 1.0/3.0*(P4x - P1x) );
const double fJ1y( P2y - P1y - 1.0/3.0*(P4y - P1y) );
const double fJ2x( P3x - P1x - 2.0/3.0*(P4x - P1x) );
const double fJ2y( P3y - P1y - 2.0/3.0*(P4y - P1y) );
const double distance2( ::std::max( fJ1x*fJ1x + fJ1y*fJ1y,
fJ2x*fJ2x + fJ2y*fJ2y) );
// stop if error measure does not improve anymore. This is a
// safety guard against floating point inaccuracies.
// stop at recursion level 128. This is a safety guard against
// floating point inaccuracies.
// stop if distance from line is guaranteed to be bounded by d
if( old_distance2 > d2 &&
recursionDepth < maxRecursionDepth &&
distance2 >= d2 )
{
// deCasteljau bezier arc, split at t=0.5
// Foley/vanDam, p. 508
const double L1x( P1x ), L1y( P1y );
const double L2x( (P1x + P2x)*0.5 ), L2y( (P1y + P2y)*0.5 );
const double Hx ( (P2x + P3x)*0.5 ), Hy ( (P2y + P3y)*0.5 );
const double L3x( (L2x + Hx)*0.5 ), L3y( (L2y + Hy)*0.5 );
const double R4x( P4x ), R4y( P4y );
const double R3x( (P3x + P4x)*0.5 ), R3y( (P3y + P4y)*0.5 );
const double R2x( (Hx + R3x)*0.5 ), R2y( (Hy + R3y)*0.5 );
const double R1x( (L3x + R2x)*0.5 ), R1y( (L3y + R2y)*0.5 );
const double L4x( R1x ), L4y( R1y );
// subdivide further
++recursionDepth;
int nGeneratedPoints(0);
nGeneratedPoints += ImplAdaptiveSubdivide(rPoly, d2, L1x, L1y, L2x, L2y, L3x, L3y, L4x, L4y, distance2, recursionDepth);
nGeneratedPoints += ImplAdaptiveSubdivide(rPoly, d2, R1x, R1y, R2x, R2y, R3x, R3y, R4x, R4y, distance2, recursionDepth);
// return number of points generated in this
// recursion branch
return nGeneratedPoints;
}
else
{
// requested resolution reached. Add end points to
// output iterator. order is preserved, since
// this is so to say depth first traversal.
rPoly.append( point::B2DPoint( P1x, P1y ) );
// return number of points generated in this
// recursion branch
return 1;
}
}
}
int adaptiveSubdivide( polygon::B2DPolygon& rPoly,
const B2DCubicBezier& rCurve,
double distanceBounds )
{
const double distance2( distanceBounds*distanceBounds );
const point::B2DPoint start( rCurve.getStartPoint() );
const point::B2DPoint control1( rCurve.getControlPointA() );
const point::B2DPoint control2( rCurve.getControlPointB() );
const point::B2DPoint end( rCurve.getEndPoint() );
return ImplAdaptiveSubdivide( rPoly,
distance2,
start.getX(), start.getY(),
control1.getX(), control1.getY(),
control2.getX(), control2.getY(),
end.getX(), end.getY(),
::std::numeric_limits<double>::max(),
0 );
}
int adaptiveSubdivide( polygon::B2DPolygon& rPoly,
const B2DQuadraticBezier& rCurve,
double distanceBounds )
{
// TODO
return 0;
}
}
}