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// -*-c++-*-
// fixg2sxd - a utility to convert fig to sxd format
// Copyright (C) 2003-2007 Alexander Bürger, acfb@users.sourceforge.net
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#include "xfigobjects.h"
#include "check.h"
#include "misc.h"
#include "vector2.h"
#include "xmlwrite.h"
#include <cmath>
// TODO: interpolated splines bad, x-splines missing
// TODO: control points are not exacty as in xfig
Spline::~Spline()
{
delete p;
delete shapefactors;
}
istream& Spline::read( istream& figfile )
{
LineFillStyle lfstmp;
lfstmp.read( figfile, sub_type, depth );
figfile >> cap_style
>> forward_arrow
>> backward_arrow
>> npoints;
keep_range( sub_type, "spline sub_type", 0, 5 );
if( (sub_type&1)==0 ) // cap_style is used only for open splines
keep_range( cap_style, "spline(open) cap_style", 0, 2 );
keep_range( forward_arrow, "spline forward_arrow", 0, 1 );
keep_range( backward_arrow, "spline backward_arrow", 0, 1 );
if( npoints<2 || npoints>65536 ) {
ostringstream err;
err << "Bad number of spline points " << npoints
<< " (accepted range = [2,65536]).";
throw err.str();
}
if( forward_arrow != 0 )
lfstmp.read_arrow( figfile, true );
if( backward_arrow != 0 )
lfstmp.read_arrow( figfile, false );
lfs = linefillstyles.insert( lfstmp ).first;
lfs->stylename_line();
lfs->stylename_fill();
lfs->stylename();
// allocate more for easier loop for closed splines
p = new Vector2f[npoints+2];
for( int i=0; i<npoints; ++i ) {
int x, y;
figfile >> x >> y;
p[i] = Vector2f(x,y);
}
shapefactors = new float[npoints+2];
for( int i=0; i<npoints; ++i )
figfile >> shapefactors[i];
return figfile;
}
ostream& Spline::write( ostream& out )
{
Vector2f moveto; // will store the initial moveto
Vector2f lineto1; // will store the initial lineto for sub_type == 0
Vector2f lineto2; // will store the final lineto for sub_type == 0
vector<Vector2f> curve; // will store sequences of controlpoint 1,
// 2 and "target point"
moveto = p[0];
Vector2f p0 = moveto; // first point of curveto
if( sub_type == 0 || sub_type == 1 ) {
// open/closed approximated spline
// using middle-points was taken from fig2dev/genps
Vector2f mid = (p[0]+p[1])/2;
p0 = mid;
if( sub_type == 0 ) {
lineto1 = mid;
} else {
p[npoints] = p[0];
p[npoints+1] = p[1];
moveto = mid;
}
const int stop = (sub_type==0) ? npoints-1 : npoints+1;
for( int i=1; i<stop; ++i ) {
const Vector2f lmid = mid;
mid = (p[i]+p[i+1])/2;
// div==0.5 is the best approximation I found, but it's not perfect
const float div = 0.5;
curve.push_back( lmid + (p[i]-lmid)*div ); // first control point
curve.push_back( mid + (p[i]- mid)*div ); // second control point
curve.push_back( mid );
}
if( sub_type == 0 )
lineto2 = p[stop];
} else if( sub_type == 2 || sub_type == 3 ) {
// open/closed interpolated spline
Vector2f con2 = p[0];
const float div = 0.5;
if( sub_type == 3 ) {
p[npoints] = p[0];
p[npoints+1] = p[1];
Vector2f a = p[npoints-1] - p[0];
Vector2f b = p[1] - p[0];
Vector2f h = (b.norm() - a.norm()).norm();
con2 = p[0] - (div*(h*a))*h;
}
const int stop = (sub_type==3) ? npoints+1 : npoints-1;
for( int i=1; i<stop; ++i ) {
Vector2f a = p[i-1] - p[i];
Vector2f b = p[i+1] - p[i];
Vector2f h = (b.norm() - a.norm()).norm();
curve.push_back( con2 ); // first control point
curve.push_back( p[i] - (div*(h*b))*h ); // second control point
curve.push_back( p[i] );
con2 = p[i] - (div*(h*a))*h;
}
if( sub_type == 2 ) {
curve.push_back( con2 );
curve.push_back( p[npoints-1] );
curve.push_back( p[npoints-1] );
}
} else {
static bool warn_xspline = false;
if( !warn_xspline ) {
warn_xspline = true;
cerr << "X-Splines are replaced by splines and need to be edited "
"by hand for now. Sorry." << endl;
}
for( int i=1; i<npoints; ++i ) {
curve.push_back( p[i-1] );
curve.push_back( p[i] );
curve.push_back( p[i] );
}
}
// calculate the extrema of the curve
float maxx = moveto.X(), maxy = moveto.Y(), minx=maxx, miny=maxy;
for( unsigned int i=0; i<curve.size(); i+=3 ) {
Vector2f p1 = curve[i ];
Vector2f p2 = curve[i+1];
Vector2f p3 = curve[i+2];
Vector2f c = (p1-p0)*3;
Vector2f b = (p2-p1)*3-c;
Vector2f a = p3-p0-b-c;
float txD = b.X()*b.X()-3*a.X()*c.X();
float txp=0, txm=1;
if( a.X() != 0 ) {
if( txD >= 0 ) {
txp = (-b.X()+sqrt(txD))/(3*a.X());
txm = (-b.X()-sqrt(txD))/(3*a.X());
}
} else if ( b.X()!=0 ) {
txp = txm = -0.5*c.X()/b.X();
}
txp = max( min( txp, 1.0f ), 0.0f );
txm = max( min( txm, 1.0f ), 0.0f );
float xp = ((a.X()*txp + b.X() )*txp + c.X())*txp + p0.X();
float xm = ((a.X()*txm + b.X() )*txm + c.X())*txm + p0.X();
maxx = max( maxx, max( xp, xm ) );
minx = min( minx, min( xp, xm ) );
float tyD = b.Y()*b.Y()-3*a.Y()*c.Y();
float typ=0, tym=1;
if( a.Y() != 0 ) {
if( tyD >= 0 ) {
typ = (-b.Y()+sqrt(tyD))/(3*a.Y());
tym = (-b.Y()-sqrt(tyD))/(3*a.Y());
}
} else if ( b.Y()!=0 ) {
typ = tym = -0.5*c.Y()/b.Y();
}
typ = max( min( typ, 1.0f ), 0.0f );
tym = max( min( tym, 1.0f ), 0.0f );
float yp = ((a.Y()*typ + b.Y() )*typ + c.Y())*typ + p0.Y();
float ym = ((a.Y()*tym + b.Y() )*tym + c.Y())*tym + p0.Y();
maxy = max( maxy, max( yp, ym ) );
miny = min( miny, min( yp, ym ) );
p0 = p3;
}
if( sub_type == 0 ) {
maxx = max( maxx, lineto1.X() );
maxx = max( maxx, lineto2.X() );
maxy = max( maxy, lineto1.Y() );
maxy = max( maxy, lineto2.Y() );
minx = min( minx, lineto1.X() );
minx = min( minx, lineto2.X() );
miny = min( miny, lineto1.Y() );
miny = min( miny, lineto2.Y() );
}
const Vector2f m( minx, miny );
#if 0
Node viewBox("draw:rect");
viewBox["draw:style-name"] << lfs->stylename_line();
viewBox["draw:z-index"] << depth2z(depth);
viewBox["draw:layer"] << "layout";
viewBox["svg:x"] << tr(minx) << "cm";
viewBox["svg:y"] << tr(miny) << "cm";
viewBox["svg:width"] << tr(maxx-minx) << "cm";
viewBox["svg:height"] << tr(maxy-miny) << "cm";
out << viewBox;
#endif
// build xml
Node path("draw:path");
path["draw:style-name"] << lfs->stylename();
path["draw:z-index"] << depth2z(depth);
path["draw:layer"] << "layout";
path["svg:x"] << tr(minx) << "cm";
path["svg:y"] << tr(miny) << "cm";
path["svg:width"] << tr(maxx-minx) << "cm";
path["svg:height"] << tr(maxy-miny) << "cm";
path["svg:viewBox"] << "0 0 " << tr_p(maxx-minx)<<' '<<tr_p(maxy-miny);
// => construct path from stored points
ostringstream& d=path["svg:d"];
d << "M " << tr_p(moveto-m);
if( sub_type == 0 )
d << "L " << tr_p(lineto1-m);
for( unsigned int i=0; i<curve.size(); i+=3 ) {
d << "C " << tr_p(curve[i]-m) << ' ' << tr_p(curve[i+1]-m)
<< ' ' << tr_p(curve[i+2]-m) << ' ';
}
if( sub_type == 0 )
d << "L " << tr_p(lineto2-m);
// fill it, if necessary
if( sub_type % 2 == 0 ) {
string line_d = d.str();
if( lfs->hasFill() ) {
d << " Z";
path["draw:style-name"] << lfs->stylename_fill();
out << path;
}
if( lfs->hasLine() ) {
path["draw:style-name"] << lfs->stylename_line();
path["svg:d"] << line_d;
out << path;
}
} else {
d << " Z";
if( lfs->hasLine() || lfs->hasFill() )
out << path;
}
return out;
}
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