tracker/pt: add failed focal length formula

1 files changed, 10 insertions, 1 deletions

diff --git a/tracker-pt/ftnoir_tracker_pt.cpp b/tracker-pt/ftnoir_tracker_pt.cpp
index d13c5545..ca25e858 100644
--- a/tracker-pt/ftnoir_tracker_pt.cpp
+++ b/tracker-pt/ftnoir_tracker_pt.cpp
@@ -65,12 +65,21 @@ bool Tracker_PT::get_focal_length(f& ret)
         using std::tan;
         using std::atan;
         using std::sqrt;
-
+#if 1
         const double w = info.res_x, h = info.res_y;
         const double diag = sqrt(w/h*w/h + h/w*h/w);
         const double diag_fov = static_cast<int>(s.fov) * M_PI / 180.;
         const double fov = 2.*atan(tan(diag_fov/2.)/diag);
         ret = .5 / tan(.5 * fov);
+#else
+        // the formula looks correct but doesn't work right regardless
+
+        const double diag_fov = s.fov * M_PI/180;
+        const double aspect = w / sqrt(w*w + h*h);
+        const double fov = 2*atan(tan(diag_fov*.5) * aspect);
+        ret = .5 / tan(fov * .5);
+        static bool once = false; if (!once) { once = true; qDebug() << "f" << ret << "fov" << (fov * 180/M_PI); }
+#endif
         return true;
     }
     return false;