sort.c

/*

g3data2 : A program for grabbing data from scanned graphs
Copyright (C) 2011 Jonas Frantz

    This file is part of g3data2.

    g3data2 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.

    g3data2 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Authors email : jonas@frantz.fi

 */

#include <gtk/gtk.h>
#include "main.h"

/****************************************************************/
/* The following sorting functions is a copy of the example in  */
/* K & R C programming 2nd ed. page 120. Some sort of quicksort.*/
/****************************************************************/
void swap3(struct PointValue *RealPos, gint i, gint j) {
	struct PointValue tmp;

	tmp.Xv = RealPos[i].Xv;
	tmp.Yv = RealPos[i].Yv;
	tmp.Xerr = RealPos[i].Xerr;
	tmp.Yerr = RealPos[i].Yerr;
	RealPos[i].Xv = RealPos[j].Xv;
	RealPos[i].Yv = RealPos[j].Yv;
	RealPos[i].Xerr = RealPos[j].Xerr;
	RealPos[i].Yerr = RealPos[j].Yerr;
	RealPos[j].Xv = tmp.Xv;
	RealPos[j].Yv = tmp.Yv;
	RealPos[j].Xerr = tmp.Xerr;
	RealPos[j].Yerr = tmp.Yerr;
}

gint compare3(struct PointValue *RealPos, gint i, gint j, gint orderv) {
	if (orderv == 1) {
		if (RealPos[i].Xv < RealPos[j].Xv)
			return (-1);
		else
			return (1);
	} else {
		if (RealPos[i].Yv < RealPos[j].Yv)
			return (-1);
		else
			return (1);
	}
}

void orderPoints(struct PointValue *RealPos, gint left, gint right, gint ordering) {
	gint i, last;

	if (left >= right)
		return;

	swap3(RealPos, left, (left + right) / 2);

	last = left;

	for (i = left + 1; i <= right; i++)
		if (compare3(RealPos, i, left, ordering) < 0)
			swap3(RealPos, ++last, i);

	swap3(RealPos, left, last);
	orderPoints(RealPos, left, last - 1, ordering);
	orderPoints(RealPos, last + 1, right, ordering);
}