+/* set the color for the pressure plot according to temporary sac rate */
+static void set_sac_color(struct graphics_context *gc, double sac)
+{
+ if (sac < 9)
+ set_source_rgba(gc, 0.0, 0.4, 0.2, 0.80);
+ else if (sac < 11)
+ set_source_rgba(gc, 0.2, 0.6, 0.2, 0.80);
+ else if (sac < 13)
+ set_source_rgba(gc, 0.4, 0.8, 0.2, 0.80);
+ else if (sac < 15)
+ set_source_rgba(gc, 0.6, 0.8, 0.2, 0.80);
+ else if (sac < 17)
+ set_source_rgba(gc, 0.8, 0.8, 0.2, 0.80);
+ else if (sac < 19)
+ set_source_rgba(gc, 0.8, 0.6, 0.2, 0.80);
+ else if (sac < 21)
+ set_source_rgba(gc, 0.8, 0.4, 0.2, 0.80);
+ else if (sac < 23)
+ set_source_rgba(gc, 0.9, 0.3, 0.2, 0.80);
+ else
+ set_source_rgba(gc, 1.0, 0.2, 0.2, 0.80);
+}
+
+/* calculate the current SAC in l/min */
+#define GET_LOCAL_SAC(_entry1, _entry2, _dive) \
+ ((GET_PRESSURE((_entry1)) - GET_PRESSURE((_entry2))) * \
+ (_dive)->cylinder[(_entry1)->cylinderindex].type.size.mliter / \
+ (((_entry2)->sec - (_entry1)->sec) / 60.0) / \
+ (1 + ((_entry1)->depth + (_entry2)->depth) / 20000.0) / \
+ 1000000.0)
+
+#define SAC_WINDOW 45 /* sliding window in seconds for current SAC calculation */
+
+static void plot_cylinder_pressure(struct graphics_context *gc, struct plot_info *pi,
+ struct dive *dive)