/* NthRoot.java
* =========================================================================
* This file is originally part of the JMathTeX Library - http://jmathtex.sourceforge.net
*
* Copyright (C) 2004-2007 Universiteit Gent
* Copyright (C) 2009 DENIZET Calixte
*
* 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.
*
* Linking this library statically or dynamically with other modules
* is making a combined work based on this library. Thus, the terms
* and conditions of the GNU General Public License cover the whole
* combination.
*
* As a special exception, the copyright holders of this library give you
* permission to link this library with independent modules to produce
* an executable, regardless of the license terms of these independent
* modules, and to copy and distribute the resulting executable under terms
* of your choice, provided that you also meet, for each linked independent
* module, the terms and conditions of the license of that module.
* An independent module is a module which is not derived from or based
* on this library. If you modify this library, you may extend this exception
* to your version of the library, but you are not obliged to do so.
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*
*/
package com.himamis.retex.renderer.share;
/**
* An atom representing an nth-root construction.
*/
public class NthRoot extends Atom {
private static final String sqrtSymbol = "sqrt";
private static final double FACTOR = 0.55;
// 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;
@Override
final public Atom duplicate() {
return setFields(new NthRoot(base, root));
}
public NthRoot(Atom base, Atom root) {
this.base = base == null ? new EmptyAtom() : base;
this.root = root == null ? new EmptyAtom() : root;
}
@Override
public Box createBox(TeXEnvironment env) {
// first create a simple square root construction
TeXFont tf = env.getTeXFont();
int style = env.getStyle();
// calculate minimum clearance clr
double 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 bs = base.createBox(env.crampStyle());
HorizontalBox b = new HorizontalBox(bs);
b.add(new SpaceAtom(TeXConstants.UNIT_MU, 1, 0, 0).createBox(env.crampStyle()));
// create root sign
double totalH = b.getHeight() + b.getDepth();
Box rootSign = DelimiterFactory.create(sqrtSymbol, env, totalH + clr + drt);
// add half the excess to clr
double 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;
}
// create box from root
Box r = root.createBox(env.rootStyle());
// shift root up
double 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();
double 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;
}
public Atom getBase() {
return base;
}
public Atom getRoot() {
return root;
}
}