output-item: Collapse the inheritance hierarchy into a single struct.

[pspp] / src / output / charts / plot-hist-cairo.c

diff --git a/src/output/charts/plot-hist-cairo.c b/src/output/charts/plot-hist-cairo.c
index a85471962fcbebf52ff445190766d049781244f4..f8663428096ff06e434d24f3d0976b880cdf57b0 100644 (file)
--- a/src/output/charts/plot-hist-cairo.c
+++ b/src/output/charts/plot-hist-cairo.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2009, 2011, 2014 Free Software Foundation, Inc.
+   Copyright (C) 2009, 2011, 2014, 2015 Free Software Foundation, Inc.
 
    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
@@ -75,8 +75,8 @@ hist_draw_bar (cairo_t *cr, const struct xrchart_geometry *geom,
   double lower;
   double height;
 
-  assert ( 0 == gsl_histogram_get_range (h, bar, &lower, &upper));
-  assert ( upper >= lower);
+  assert (0 == gsl_histogram_get_range (h, bar, &lower, &upper));
+  assert (upper >= lower);
 
   const double x_pos =
     (lower - geom->axis[SCALE_ABSCISSA].min) * geom->axis[SCALE_ABSCISSA].scale
@@ -100,17 +100,17 @@ hist_draw_bar (cairo_t *cr, const struct xrchart_geometry *geom,
 }
 
 void
-xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
+xrchart_draw_histogram (const struct chart *chart, cairo_t *cr,
                         struct xrchart_geometry *geom)
 {
-  struct histogram_chart *h = to_histogram_chart (chart_item);
+  struct histogram_chart *h = to_histogram_chart (chart);
   int i;
   int bins;
 
   xrchart_write_title (cr, geom, _("HISTOGRAM"));
 
   xrchart_write_ylabel (cr, geom, _("Frequency"));
-  xrchart_write_xlabel (cr, geom, chart_item_get_title (chart_item));
+  xrchart_write_xlabel (cr, geom, chart_get_title (chart));
 
   if (h->gsl_hist == NULL)
     {
@@ -118,9 +118,11 @@ xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
       return;
     }
 
-  xrchart_write_yscale (cr, geom, 0, gsl_histogram_max_val (h->gsl_hist));
-  xrchart_write_xscale (cr, geom, gsl_histogram_min (h->gsl_hist),
-                       gsl_histogram_max (h->gsl_hist));
+  if (! xrchart_write_yscale (cr, geom, 0, gsl_histogram_max_val (h->gsl_hist)))
+    return;
+  if (! xrchart_write_xscale (cr, geom, gsl_histogram_min (h->gsl_hist),
+                              gsl_histogram_max (h->gsl_hist)))
+    return;
 
 
   /* Draw the ticks and compute if the rendered tick text is wider than the bin */
@@ -149,6 +151,13 @@ xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
       /* Therefore the pdf has to be scaled accordingly such that the integrals are equal               */
       ordinate_scale = binwidth * gsl_histogram_sum(h->gsl_hist);
 
+      /* Clip normal curve to the rectangle formed by the axes. */
+      cairo_save (cr);
+      cairo_rectangle (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min,
+                       geom->axis[SCALE_ABSCISSA].data_max - geom->axis[SCALE_ABSCISSA].data_min,
+                       geom->axis[SCALE_ORDINATE].data_max - geom->axis[SCALE_ORDINATE].data_min);
+      cairo_clip (cr);
+
       cairo_move_to (cr, geom->axis[SCALE_ABSCISSA].data_min, geom->axis[SCALE_ORDINATE].data_min);
       for (x = geom->axis[SCALE_ABSCISSA].min;
           x <= geom->axis[SCALE_ABSCISSA].max;
@@ -161,5 +170,7 @@ xrchart_draw_histogram (const struct chart_item *chart_item, cairo_t *cr,
           cairo_line_to (cr, x_pos, y_pos);
        }
       cairo_stroke (cr);
+
+      cairo_restore (cr);
     }
 }