performance

diff --git a/src/graph.c b/src/graph.c
index c3f4d5c..de23bb8 100644 (file)
--- a/src/graph.c
+++ b/src/graph.c
@@ -171,7 +171,7 @@ static void draw_sensor_curve(struct psensor *s,
                              int g_xoff,
                              int g_yoff)
 {
-       int first, i, x, y, t;
+       int first, i, x, y, t, dt, vdt;
        double v;
 
        cairo_set_source_rgb(cr,
@@ -179,15 +179,20 @@ static void draw_sensor_curve(struct psensor *s,
                             s->color->f_green,
                             s->color->f_blue);
 
+       dt = et - bt;
        first = 1;
        for (i = 0; i < s->values_max_length; i++) {
                t = s->measures[i].time.tv_sec;
                v = s->measures[i].value.d_num;
 
-               if (v == UNKNOWN_DBL_VALUE || !t || (t - bt) < 0)
+               if (v == UNKNOWN_DBL_VALUE || !t)
                        continue;
 
-               x = (t - bt) * g_width / (et - bt) + g_xoff;
+               vdt = t - bt;
+               if (vdt < 0)
+                       continue;
+
+               x = vdt * g_width / dt + g_xoff;
 
                y = compute_y(v, min, max, g_height, g_yoff);