6a8a48eb3c28e3f9ed266477bb6a345d37522d3e
1 /*
2 * Inkscape::Debug::GdkEventLatencyTracker - tracks backlog of GDK events
3 *
4 * Authors:
5 * MenTaLguY <mental@rydia.net>
6 *
7 * Copyright (C) 2008 MenTaLguY
8 *
9 * Released under GNU GPL, read the file 'COPYING' for more information
10 */
12 #include "debug/gdk-event-latency-tracker.h"
13 #include "prefs-utils.h"
15 namespace Inkscape {
16 namespace Debug {
18 GdkEventLatencyTracker::GdkEventLatencyTracker()
19 : start_seconds(0.0), max_latency(0.0), skew(1.0)
20 {
21 elapsed.stop();
22 elapsed.reset();
23 }
25 boost::optional<double> GdkEventLatencyTracker::process(GdkEvent const *event) {
26 guint32 const timestamp=gdk_event_get_time(const_cast<GdkEvent *>(event));
27 if (timestamp == GDK_CURRENT_TIME) {
28 return boost::optional<double>();
29 }
30 double const timestamp_seconds = timestamp / 1000.0;
32 if (start_seconds == 0.0) {
33 elapsed.start();
34 start_seconds = timestamp_seconds;
35 skew = prefs_get_double_attribute_limited("debug.latency", "skew", 1.0, 0.5, 2.0);
36 return boost::optional<double>(0.0);
37 } else {
38 double const current_seconds = (elapsed.elapsed() * skew) + start_seconds;
39 double delta = current_seconds - timestamp_seconds;
40 if (delta < 0.0) {
41 start_seconds += -delta;
42 delta = 0.0;
43 } else if (delta > max_latency) {
44 max_latency = delta;
45 }
46 return boost::optional<double>(delta);
47 }
48 }
50 GdkEventLatencyTracker &GdkEventLatencyTracker::default_tracker() {
51 static GdkEventLatencyTracker tracker;
52 return tracker;
53 }
55 }
56 }
58 /*
59 Local Variables:
60 mode:c++
61 c-file-style:"stroustrup"
62 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
63 indent-tabs-mode:nil
64 fill-column:99
65 End:
66 */
67 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :