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/* NthRoot.java
* =========================================================================
* This file is part of the JMathTeX Library - http://jmathtex.sourceforge.net
*
* Copyright (C) 2004-2007 Universiteit Gent
*
* 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.
*
* A copy of the GNU General Public License can be found in the file
* LICENSE.txt provided with the source distribution of this program (see
* the META-INF directory in the source jar). This license can also be
* found on the GNU website at http://www.gnu.org/licenses/gpl.html.
*
* If you did not receive a copy of the GNU General Public License along
* with this program, contact the lead developer, or write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*/
package be.ugent.caagt.jmathtex;
/**
* An atom representing an nth-root construction.
*/
class NthRoot extends Atom {
private static final String sqrtSymbol = "sqrt";
private static final float FACTOR = 0.55f;
// base atom to be put under the root sign
private final Atom base;
// root atom to be put in the upper left corner above the root sign
private final Atom root;
public NthRoot(Atom base, Atom root) {
this.base = base;
this.root = root;
}
public Box createBox(TeXEnvironment env) {
// first create a simple square root construction
TeXFont tf = env.getTeXFont();
int style = env.getStyle();
// calculate minimum clearance clr
float clr, drt = tf.getDefaultRuleThickness(style);
if (style < TeXConstants.STYLE_TEXT)
clr = tf
.getXHeight(style, tf.getChar(sqrtSymbol, style).getFontCode());
else
clr = drt;
clr = drt + Math.abs(clr) / 4;
// cramped style for the formula under the root sign
Box b = base.createBox(env.crampStyle());
// create root sign
float totalH = b.getHeight() + b.getDepth();
Box rootSign = DelimiterFactory.create(sqrtSymbol, env, totalH + clr
+ drt);
// add half the excess to clr
float delta = rootSign.getDepth() - (totalH + clr);
clr += delta / 2;
// create total box
rootSign.setShift(-(b.getHeight() + clr));
OverBar ob = new OverBar(b, clr, rootSign.getHeight());
ob.setShift(-(b.getHeight() + clr + drt));
HorizontalBox squareRoot = new HorizontalBox(rootSign);
squareRoot.add(ob);
if (root == null)
// simple square root
return squareRoot;
else { // nthRoot, not a simple square root
// create box from root
Box r = root.createBox(env.rootStyle());
// shift root up
float bottomShift = FACTOR
* (squareRoot.getHeight() + squareRoot.getDepth());
r.setShift(squareRoot.getDepth() - r.getDepth() - bottomShift);
// negative kern
Box negativeKern = new SpaceAtom(TeXConstants.UNIT_MU, -10f, 0, 0)
.createBox(env);
// arrange both boxes together with the negative kern
Box res = new HorizontalBox();
float pos = r.getWidth() + negativeKern.getWidth();
if (pos < 0)
res.add(new StrutBox(-pos, 0, 0, 0));
res.add(r);
res.add(negativeKern);
res.add(squareRoot);
return res;
}
}
}
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