--- /dev/null
+/* PSPP - draws pie charts of sample statistics
+
+Copyright (C) 2004 Free Software Foundation, Inc.
+Written by John Darrington <john@darrington.wattle.id.au>
+
+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., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
+
+
+#include "config.h"
+#include "piechart.h"
+#include "chart.h"
+#include <float.h>
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include "str.h"
+#include "value-labels.h"
+#include "misc.h"
+#include "plot-chart.h"
+
+/* Pie charts of course need to know Pi :) */
+#ifndef M_PI
+#define M_PI ( 22.0 / 7.0 )
+#endif
+
+
+
+/* Draw a single slice of the pie */
+static void
+draw_segment(struct chart *ch,
+ double centre_x, double centre_y,
+ double radius,
+ double start_angle, double segment_angle,
+ const char *colour) ;
+
+
+
+/* Draw a piechart */
+void
+piechart_plot(const char *title, const struct slice *slices, int n_slices)
+{
+ int i;
+ double total_magnetude=0;
+
+ struct chart *ch = chart_create();
+
+ const double left_label = ch->data_left +
+ (ch->data_right - ch->data_left)/10.0;
+
+ const double right_label = ch->data_right -
+ (ch->data_right - ch->data_left)/10.0;
+
+ const double centre_x = (ch->data_right + ch->data_left ) / 2.0 ;
+ const double centre_y = (ch->data_top + ch->data_bottom ) / 2.0 ;
+
+ const double radius = min(
+ 5.0 / 12.0 * (ch->data_top - ch->data_bottom),
+ 1.0 / 4.0 * (ch->data_right - ch->data_left)
+ );
+
+
+ chart_write_title(ch, title);
+
+ for (i = 0 ; i < n_slices ; ++i )
+ total_magnetude += slices[i].magnetude;
+
+ for (i = 0 ; i < n_slices ; ++i )
+ {
+ static double angle=0.0;
+
+ const double segment_angle =
+ slices[i].magnetude / total_magnetude * 2 * M_PI ;
+
+ const double label_x = centre_x -
+ radius * sin(angle + segment_angle/2.0);
+
+ const double label_y = centre_y +
+ radius * cos(angle + segment_angle/2.0);
+
+ /* Fill the segment */
+ draw_segment(ch,
+ centre_x, centre_y, radius,
+ angle, segment_angle,
+ data_colour[i]);
+
+ /* Now add the labels */
+ if ( label_x < centre_x )
+ {
+ pl_line_r(ch->lp, label_x, label_y,
+ left_label, label_y );
+ pl_moverel_r(ch->lp,0,5);
+ pl_alabel_r(ch->lp,0,0,slices[i].label);
+ }
+ else
+ {
+ pl_line_r(ch->lp,
+ label_x, label_y,
+ right_label, label_y
+ );
+ pl_moverel_r(ch->lp,0,5);
+ pl_alabel_r(ch->lp,'r',0,slices[i].label);
+ }
+
+ angle += segment_angle;
+
+ }
+
+ /* Draw an outline to the pie */
+ pl_filltype_r(ch->lp,0);
+ pl_fcircle_r (ch->lp, centre_x, centre_y, radius);
+
+ chart_submit(ch);
+}
+
+static void
+fill_segment(struct chart *ch,
+ double x0, double y0,
+ double radius,
+ double start_angle, double segment_angle) ;
+
+
+/* Fill a segment with the current fill colour */
+static void
+fill_segment(struct chart *ch,
+ double x0, double y0,
+ double radius,
+ double start_angle, double segment_angle)
+{
+
+ const double start_x = x0 - radius * sin(start_angle);
+ const double start_y = y0 + radius * cos(start_angle);
+
+ const double stop_x =
+ x0 - radius * sin(start_angle + segment_angle);
+
+ const double stop_y =
+ y0 + radius * cos(start_angle + segment_angle);
+
+ assert(segment_angle <= 2 * M_PI);
+ assert(segment_angle >= 0);
+
+ if ( segment_angle > M_PI )
+ {
+ /* Then we must draw it in two halves */
+ fill_segment(ch, x0, y0, radius, start_angle, segment_angle / 2.0 );
+ fill_segment(ch, x0, y0, radius, start_angle + segment_angle / 2.0,
+ segment_angle / 2.0 );
+ }
+ else
+ {
+ pl_move_r(ch->lp, x0, y0);
+
+ pl_cont_r(ch->lp, stop_x, stop_y);
+ pl_cont_r(ch->lp, start_x, start_y);
+
+ pl_arc_r(ch->lp,
+ x0, y0,
+ stop_x, stop_y,
+ start_x, start_y
+ );
+
+ pl_endpath_r(ch->lp);
+ }
+}
+
+
+
+/* Draw a single slice of the pie */
+static void
+draw_segment(struct chart *ch,
+ double x0, double y0,
+ double radius,
+ double start_angle, double segment_angle,
+ const char *colour)
+{
+ const double start_x = x0 - radius * sin(start_angle);
+ const double start_y = y0 + radius * cos(start_angle);
+
+ pl_savestate_r(ch->lp);
+
+ pl_savestate_r(ch->lp);
+ pl_colorname_r(ch->lp, colour);
+
+ pl_pentype_r(ch->lp,1);
+ pl_filltype_r(ch->lp,1);
+
+ fill_segment(ch, x0, y0, radius, start_angle, segment_angle);
+ pl_restorestate_r(ch->lp);
+
+ /* Draw line dividing segments */
+ pl_pentype_r(ch->lp, 1);
+ pl_fline_r(ch->lp, x0, y0, start_x, start_y);
+
+
+ pl_restorestate_r(ch->lp);
+}
+
projects / pspp-builds.git / blobdiff