tracker/pt, options: fix threshold slider

It's only the tie_setting(slider_value, QSlider) that
has race-free slider updates. Needed to update the
threshold slider representation.

Remove the tie_setting(int, QSlider) overload since it
doesn't have the logic.

Add a migration.

Add base_value::notify() for use-cases like the
checkbox updating the label.

4 files changed, 34 insertions, 20 deletions

diff --git a/tracker-pt/ftnoir_tracker_pt_dialog.cpp b/tracker-pt/ftnoir_tracker_pt_dialog.cpp
index a4b8c668..4094f4dc 100644
--- a/tracker-pt/ftnoir_tracker_pt_dialog.cpp
+++ b/tracker-pt/ftnoir_tracker_pt_dialog.cpp
@@ -28,7 +28,7 @@ TrackerDialog_PT::TrackerDialog_PT()
     tie_setting(s.cam_res_y, ui.res_y_spin);
     tie_setting(s.cam_fps, ui.fps_spin);
 
-    tie_setting(s.threshold, ui.threshold_slider);
+    tie_setting(s.threshold_slider, ui.threshold_slider);
 
     tie_setting(s.min_point_size, ui.mindiam_spin);
     tie_setting(s.max_point_size, ui.maxdiam_spin);
@@ -94,22 +94,32 @@ TrackerDialog_PT::TrackerDialog_PT()
 
     tie_setting(s.blob_color, ui.blob_color);
 
-    tie_setting(s.threshold, ui.threshold_value_display, [this](int x) {
-        if (!s.auto_threshold)
-            return tr("Brightness %1/255").arg(x);
-        else
-        {
-            CamInfo info;
-            int w = 640, h = 480;
+    tie_setting(s.threshold_slider, ui.threshold_value_display, [this](const slider_value& val) {
+        return threshold_display_text(int(val));
+    });
 
-            if (tracker && tracker->get_cam_info(&info) && info.res_x * info.res_y != 0)
-                w = info.res_x, h = info.res_y;
+    // refresh threshold display on auto-threshold checkbox state change
+    tie_setting(s.auto_threshold,
+                this,
+                [this](bool) { s.threshold_slider.notify(); });
+}
 
-            double value = PointExtractor::threshold_radius_value(w, h, x);
+QString TrackerDialog_PT::threshold_display_text(int threshold_value)
+{
+    if (!s.auto_threshold)
+        return tr("Brightness %1/255").arg(threshold_value);
+    else
+    {
+        CamInfo info;
+        int w = 640, h = 480;
 
-            return tr("LED radius %1 pixels").arg(value, 0, 'f', 2);
-        }
-    });
+        if (tracker && tracker->get_cam_info(&info) && info.res_x * info.res_y != 0)
+            w = info.res_x, h = info.res_y;
+
+        double value = PointExtractor::threshold_radius_value(w, h, threshold_value);
+
+        return tr("LED radius %1 pixels").arg(value, 0, 'f', 2);
+    }
 }
 
 void TrackerDialog_PT::startstop_trans_calib(bool start)
diff --git a/tracker-pt/ftnoir_tracker_pt_dialog.h b/tracker-pt/ftnoir_tracker_pt_dialog.h
index 59519601..c1c25fb0 100644
--- a/tracker-pt/ftnoir_tracker_pt_dialog.h
+++ b/tracker-pt/ftnoir_tracker_pt_dialog.h
@@ -38,6 +38,8 @@ public slots:
 signals:
     void poll_tracker_info();
 private:
+    QString threshold_display_text(int threshold_value);
+
     settings_pt s;
     Tracker_PT* tracker;
     QTimer timer, calib_timer;
diff --git a/tracker-pt/ftnoir_tracker_pt_settings.h b/tracker-pt/ftnoir_tracker_pt_settings.h
index 6bbba16b..8250edba 100644
--- a/tracker-pt/ftnoir_tracker_pt_settings.h
+++ b/tracker-pt/ftnoir_tracker_pt_settings.h
@@ -26,8 +26,7 @@ struct settings_pt : opts
     value<QString> camera_name;
     value<int> cam_res_x,
                cam_res_y,
-               cam_fps,
-               threshold;
+               cam_fps;
     value<double> min_point_size, max_point_size;
 
     value<int> m01_x, m01_y, m01_z;
@@ -45,13 +44,15 @@ struct settings_pt : opts
     value<bool> auto_threshold;
     value<pt_color_type> blob_color;
 
+    value<slider_value> threshold_slider;
+
     settings_pt() :
         opts("tracker-pt"),
         camera_name(b, "camera-name", ""),
         cam_res_x(b, "camera-res-width", 640),
         cam_res_y(b, "camera-res-height", 480),
         cam_fps(b, "camera-fps", 30),
-        threshold(b, "threshold-primary", 128),
+        threshold_slider(b, "threshold-slider", slider_value(128, 0, 255)),
         min_point_size(b, "min-point-size", 1),
         max_point_size(b, "max-point-size", 50),
         m01_x(b, "m_01-x", 0),
diff --git a/tracker-pt/point_extractor.cpp b/tracker-pt/point_extractor.cpp
index adb23d52..40054084 100644
--- a/tracker-pt/point_extractor.cpp
+++ b/tracker-pt/point_extractor.cpp
@@ -180,10 +180,11 @@ void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame
     const double region_size_min = s.min_point_size;
     const double region_size_max = s.max_point_size;
 
+    const int threshold_slider_value = s.threshold_slider.to<int>();
+
     if (!s.auto_threshold)
     {
-        const int thres = s.threshold;
-        cv::threshold(frame_gray, frame_bin, thres, 255, cv::THRESH_BINARY);
+        cv::threshold(frame_gray, frame_bin, threshold_slider_value, 255, cv::THRESH_BINARY);
     }
     else
     {
@@ -200,7 +201,7 @@ void PointExtractor::extract_points(const cv::Mat& frame, cv::Mat& preview_frame
                      (int const*) &hist_size,
                      &ranges);
 
-        const double radius = threshold_radius_value(frame.cols, frame.rows, s.threshold);
+        const double radius = threshold_radius_value(frame.cols, frame.rows, threshold_slider_value);
 
         float const* restrict_ptr ptr = reinterpret_cast<float const* restrict_ptr>(hist.ptr(0));
         const unsigned area = uround(3 * M_PI * radius*radius);