1 files changed, 57 insertions, 0 deletions
diff --git a/lib/ephy-zoom.c b/lib/ephy-zoom.c
new file mode 100644
index 000000000..af5d5f771
--- /dev/null
+++ b/lib/ephy-zoom.c
@@ -0,0 +1,57 @@
+/*
+ *  Copyright (C) 2003 Christian Persch
+ *
+ *  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, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "ephy-zoom.h"
+
+#include <math.h>
+
+guint
+ephy_zoom_get_zoom_level_index (float level)
+{
+	guint i;
+	float previous, current, mean;
+
+	previous = zoom_levels[0].level;
+
+	for (i = 1; i < n_zoom_levels; i++)
+	{
+		current = zoom_levels[i].level;
+		mean = sqrt (previous * current);
+
+		if (level <= mean) return i - 1;
+
+		previous = current;
+	}
+
+	return n_zoom_levels - 1;
+}
+
+
+float
+ephy_zoom_get_changed_zoom_level (float level, gint steps)
+{
+	guint index;
+
+	index = ephy_zoom_get_zoom_level_index (level);
+	return zoom_levels[CLAMP(index + steps, 0, n_zoom_levels - 1)].level;
+}
+
+float	ephy_zoom_get_nearest_zoom_level (float level)
+{
+	return ephy_zoom_get_changed_zoom_level (level, 0);
+}