overlay: Expose sampling period/frequency as a user parameter

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/overlay/overlay.c b/overlay/overlay.c
index c99f58b..3ec240d 100644 (file)
--- a/overlay/overlay.c
+++ b/overlay/overlay.c
@@ -708,6 +708,21 @@ static void signal_snapshot(int sig)
        take_snapshot = sig;
 }
 
+static int get_sample_period(struct config *config)
+{
+       const char *value;
+
+       value = config_get_value(config, "sampling", "period");
+       if (value && atoi(value) > 0)
+               return atoi(value);
+
+       value = config_get_value(config, "sampling", "frequency");
+       if (value && atoi(value) > 0)
+               return 1000000 / atoi(value);
+
+       return 500000;
+}
+
 int main(int argc, char **argv)
 {
        static struct option long_options[] = {
@@ -718,7 +733,7 @@ int main(int argc, char **argv)
        };
        struct overlay_context ctx;
        struct config config;
-       int index;
+       int index, sample_period;
        int i;
 
        config_init(&config);
@@ -760,10 +775,10 @@ int main(int argc, char **argv)
        init_gpu_freq(&ctx, &ctx.gpu_freq);
        init_gem_objects(&ctx, &ctx.gem_objects);
 
+       sample_period = get_sample_period(&config);
+
        i = 0;
        while (1) {
-               usleep(500*1000);
-
                ctx.cr = cairo_create(ctx.surface);
                cairo_set_operator(ctx.cr, CAIRO_OPERATOR_CLEAR);
                cairo_paint(ctx.cr);
@@ -797,6 +812,8 @@ int main(int argc, char **argv)
                        cairo_surface_write_to_png(ctx.surface, buf);
                        take_snapshot = 0;
                }
+
+               usleep(sample_period);
        }
 
        return 0;