goffice r2355 - in trunk: . goffice/graph

[mortenw svn gnome org]

Author: mortenw
Date: Sat Mar 28 22:58:32 2009
New Revision: 2355
URL: http://svn.gnome.org/viewvc/goffice?rev=2355&view=rev

Log:
2009-03-28  Morten Welinder  <terra gnome org>

	* goffice/graph/gog-axis.c (map_linear_calc_ticks): Make sure
	we get zero and not almost-zero when we need to.



Modified:
   trunk/ChangeLog
   trunk/goffice/graph/gog-axis.c

Modified: trunk/goffice/graph/gog-axis.c
==============================================================================
--- trunk/goffice/graph/gog-axis.c	(original)
+++ trunk/goffice/graph/gog-axis.c	Sat Mar 28 22:58:32 2009
@@ -667,6 +667,7 @@
 	int t, maj_i, maj_N, min_i, min_N, N;
 	double maj_step, min_step;
 	double range, ratio;
+	double zero_threshold;
 
 	if (!gog_axis_get_bounds (axis, &minimum, &maximum)) {
 		gog_axis_set_ticks (axis, 2, create_invalid_axis_ticks (0.0, 1.0));
@@ -686,6 +687,8 @@
 	min_N = (ratio >= G_MAXINT ? 1 : (int)ratio);
 	min_step = maj_step / min_N;
 
+	zero_threshold = maj_step * DBL_EPSILON;
+
 	/*
 	 * We used to round minimum to nearest maj_step, but that is very
 	 * wrong:
@@ -721,6 +724,8 @@
 	t = 0;
 	for (maj_i = 0; ; maj_i++) {
 		double maj_pos = minimum + maj_i * maj_step;
+		if (fabs (maj_pos) < maj_i * zero_threshold)
+			maj_pos = 0;
 
 		ticks[t].position = maj_pos;
 		ticks[t].type = GOG_AXIS_TICK_MAJOR;