From 639e14e2a563215eae3f0e5608091d816bfb6f9c Mon Sep 17 00:00:00 2001
From: Philip Balister
Date: Fri, 29 Apr 2011 14:51:07 -0400
Subject: qtqui-sink : Do not run the FFT unless updating the display.

Signed-off-by: Philip Balister <philip@opensdr.com>
---
 gr-qtgui/include/qtgui_sink_c.h |  3 +++
 gr-qtgui/lib/qtgui_sink_c.cc    | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/gr-qtgui/include/qtgui_sink_c.h b/gr-qtgui/include/qtgui_sink_c.h
index b04706b14..28c0f1372 100644
--- a/gr-qtgui/include/qtgui_sink_c.h
+++ b/gr-qtgui/include/qtgui_sink_c.h
@@ -29,6 +29,7 @@
 #include <gr_firdes.h>
 #include <gri_fft.h>
 #include <qapplication.h>
+#include <gruel/high_res_timer.h>
 #include "SpectrumGUIClass.h"
 
 class qtgui_sink_c;
@@ -78,6 +79,8 @@ private:
   double d_center_freq;
   double d_bandwidth;
   std::string d_name;
+  gruel::high_res_timer_type  d_last_update;
+  bool d_update_active;
   
   bool d_shift;
   gri_fft_complex *d_fft;
diff --git a/gr-qtgui/lib/qtgui_sink_c.cc b/gr-qtgui/lib/qtgui_sink_c.cc
index 965be0773..625ddbdf6 100644
--- a/gr-qtgui/lib/qtgui_sink_c.cc
+++ b/gr-qtgui/lib/qtgui_sink_c.cc
@@ -125,6 +125,9 @@ qtgui_sink_c::initialize()
 
   // initialize update time to 10 times a second
   set_update_time(0.1);
+
+  d_last_update = gruel::high_res_timer_now();
+  d_update_active = false;
 }
 
 
@@ -270,6 +273,14 @@ qtgui_sink_c::general_work (int noutput_items,
     unsigned int datasize = noutput_items - i;
     unsigned int resid = d_fftsize-d_index;
 
+    if (!d_update_active && (gruel::high_res_timer_now() - d_last_update) < d_update_time) {
+      consume_each(noutput_items);
+      return noutput_items;
+    } else {
+      d_last_update = gruel::high_res_timer_now();
+      d_update_active = true;
+    }
+
     // If we have enough input for one full FFT, do it
     if(datasize >= resid) {
       const gruel::high_res_timer_type currentTime = gruel::high_res_timer_now();
@@ -284,6 +295,7 @@ qtgui_sink_c::general_work (int noutput_items,
       d_main_gui->UpdateWindow(true, d_fft->get_outbuf(), d_fftsize,
 			       NULL, 0, (float*)d_residbuf, d_fftsize,
 			       currentTime, true);
+      d_update_active = false;
     }
     // Otherwise, copy what we received into the residbuf for next time
     else {
-- 
cgit