Add our own eye tracker as a gaze source in ft-gaze and the probe

ft-gaze reads frame-eyes' /dev/shm/frame-eyes-gaze and reports it as the source "own",
with each eye's gaze, where each lands on the screen, and its slip. The probe gets a
SteamVR / Own tracker toggle. With Own tracker on, it hides SteamVR's gaze and draws a
red dot per eye, its calibration fits fe-trackd's own calibration, and practice clicks
teach fe-trackd instead of the probe's correction.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

gaze/README.md

@@ -32,6 +32,7 @@ Lessons are logged to `pointer-lessons.jsonl`: the raw gaze, the true direction,
 | SteamVR action | An `eyetracking` action bound to `/user/head/eyetracking` (`actions/`), read with `IVRInput::GetEyeTrackingDataRelativeToNow`. This is the supported way. |
 | mmap set 1, set 2 | `/dev/shm/eye-server.mmap`, which SteamVR's eyetracking process writes for the HMD driver (`driver_cv.so`). It has two sets of per-eye directions in head space: set 1 is filtered, and its two eyes always share one pitch; set 2 is each eye's own reading. After each set come the tracker's variances for each eye, and at the end each eye's raw measurement and its variance (the tracker's confidence in that frame), which ft-gaze passes on for the fit check. |
 | Left eye, right eye | Each eye alone, from set 2: calibrate and test them to see what one eye is worth against both. The layout is undocumented (offsets are in `ft-gaze.cpp`) and may change with a SteamVR update. ft-gaze maps it read-only; the file also carries calibration clicks to the tracker and must never be written. |
+| Own tracker | Our own tracker, from `~/Desktop/Projects/frame-eyes` (experimental). `tools/fe-live` runs it: a root helper copies the eye-camera frames out of SteamVR's buffers (read-only) and `fe-trackd` finds the pupils and glints and publishes the gaze in `/dev/shm/frame-eyes-gaze`. It keeps its own calibration, not SteamVR's: the probe's calibration with the tracker toggle on Own tracker fits it, and practice clicks teach it how far the headset has moved on your face since. With Own tracker on, the probe hides SteamVR's gaze and draws a red dot where each eye alone puts it. ft-gaze reports it as `own` while it's running, and as `{"ok":0}` otherwise. |
 
 The tracker stops when the headset is off your head. SteamVR also calibrates gaze on its own from laser-mouse clicks, treating each click as a spot you were looking at. That includes mouse clicks through the Frametop pointer, so a click where the pointer's dot isn't what you're looking at teaches SteamVR a wrong sample (it only takes clicks within 5 degrees of your gaze). In the probe, use Enter or Space as the trigger: keys don't go through SteamVR's laser. See `Accept usercal` in `~/.local/share/Steam/logs/eyetracking.txt`. When the tracker loses an eye, the same log says `CEyePoseUKF L: Large dt` (or `R`) as it starts that eye over.
 

gaze/ft-gaze.cpp

@@ -8,7 +8,7 @@
 //
 //   {"t":<sample time, CLOCK_MONOTONIC_RAW s>,"age":<ms old when read>,"n":<sample counter>,
 //    "head":{"yaw":..,"pitch":..,"hit":HIT},          head forward ray (for head nudging)
-//    "src":{"action":SRC,"mmap1":SRC,"mmap2":SRC,"left":SRC,"right":SRC},"eye":EYE}
+//    "src":{"action":SRC,"mmap1":SRC,"mmap2":SRC,"left":SRC,"right":SRC,"own":SRC},"eye":EYE}
 //   SRC = {"hy":..,"hp":..,"hit":HIT} or {"ok":0}    hy/hp: gaze direction relative to the
 //                                                     head, degrees (yaw +left, pitch +up)
 //         mmap1 adds "open":[l,r] (probably eye openness, 0 in a blink) and "dist" (vergence
@@ -21,6 +21,12 @@
 //         (set 1's eyes always share one pitch, and while it's lost an eye it keeps that
 //         eye's yaw where it was: set 2 is each eye's own reading). From the head's origin,
 //         not the eye's.
+//    "own":SRC                                        our own tracker (frame-eyes fe-trackd), from
+//         /dev/shm/frame-eyes-gaze; adds "age" (ms since its frame), "eyes":[[hy,hp],[hy,hp]]
+//         (left, right; null for an eye it doesn't see), "ehit":[HIT,HIT] where each of those
+//         lands, and "slip":[[x,y],[x,y]] (left, right: each eye's shift in its camera image
+//         since the calibration, pixels; null until a click has measured it). {"ok":0}
+//         without the file or when it's over 100 ms old.
 //   EYE = {"q":[l,r],"m":[[x,y],[x,y]],"new":[l,r]}  the tracker's latest measurement of
 //         each eye before filtering: "m" (camera-relative, undocumented units), "q" its
 //         variance (about 2e-5 on a clear view of the eye, rising as the lid or lashes get
@@ -157,6 +163,69 @@ bool ReadSample(const EyeFile &f, EyeSample &s) {
     return false;
 }
 
+// --- Our own tracker: /dev/shm/frame-eyes-gaze, written by frame-eyes' fe-trackd ---
+// Layout (fe-trackd's docstring): u32 seq (odd while written), u32 version, f64 t, f32 yaw,
+// pitch, u32 flags (bit 0 right eye, 1 left, 2 right slip known, 3 left), u32 n, then f32
+// right yaw, pitch, left yaw, pitch; slip right x, y, left x, y; pupils (unused here).
+struct OwnSample {
+    double t = 0;
+    float yaw = 0, pitch = 0;
+    uint32_t flags = 0, n = 0;
+    float eyes[4] = {}, slip[4] = {};
+};
+
+class OwnFile {
+public:
+    // Reopened when it appears or is replaced, since fe-trackd may start after us.
+    bool Read(OwnSample &o) {
+        const double now = NowRaw();
+        if (!p_ || now - checked_ > 2.0) Reopen(now);
+        if (!p_) return false;
+        for (int attempt = 0; attempt < 4; ++attempt) {
+            uint32_t s0, s1, version;
+            std::memcpy(&s0, p_, 4);
+            if (s0 & 1) continue;
+            std::atomic_thread_fence(std::memory_order_acquire);
+            std::memcpy(&version, p_ + 4, 4);
+            std::memcpy(&o.t, p_ + 8, 8);
+            std::memcpy(&o.yaw, p_ + 16, 4);
+            std::memcpy(&o.pitch, p_ + 20, 4);
+            std::memcpy(&o.flags, p_ + 24, 4);
+            std::memcpy(&o.n, p_ + 28, 4);
+            std::memcpy(o.eyes, p_ + 32, sizeof o.eyes);
+            std::memcpy(o.slip, p_ + 48, sizeof o.slip);
+            std::atomic_thread_fence(std::memory_order_acquire);
+            std::memcpy(&s1, p_, 4);
+            if (s0 == s1) return version == 1;
+        }
+        return false;
+    }
+
+private:
+    static constexpr size_t kSize = 128;
+    void Reopen(double now) {
+        checked_ = now;
+        struct stat st {};
+        if (stat("/dev/shm/frame-eyes-gaze", &st) != 0) return Close();
+        if (p_ && st.st_ino == ino_) return;
+        Close();
+        const int fd = open("/dev/shm/frame-eyes-gaze", O_RDONLY | O_CLOEXEC);
+        if (fd < 0) return;
+        if (fstat(fd, &st) == 0 && size_t(st.st_size) >= kSize) {
+            void *m = mmap(nullptr, kSize, PROT_READ, MAP_SHARED, fd, 0);
+            if (m != MAP_FAILED) p_ = static_cast<const uint8_t *>(m), ino_ = st.st_ino;
+        }
+        close(fd);
+    }
+    void Close() {
+        if (p_) munmap(const_cast<uint8_t *>(p_), kSize);
+        p_ = nullptr;
+    }
+    const uint8_t *p_ = nullptr;
+    ino_t ino_ = 0;
+    double checked_ = -1e9;
+};
+
 // --- Screens from ft-screens ---
 struct Screen {
     int index = 0;
@@ -394,6 +463,7 @@ int main(int argc, char **argv) {
     const bool haveMmap = eyes.Open();
     std::fprintf(stderr, "ft-gaze: eye-server.mmap %s\n", haveMmap ? "open" : "not available");
 
+    OwnFile ownFile;
     Screens screens;
     screens.Start();
     PoseHistory history;
@@ -482,14 +552,42 @@ int main(int argc, char **argv) {
                 eye = extra;
             }
 
+            // Our tracker: its own sample time picks the head pose, like the mmap's.
+            std::string own = "{\"ok\":0}";
+            OwnSample o;
+            if (ownFile.Read(o) && now - o.t < 0.1) {
+                vr::HmdMatrix34_t headOwn = headNow;
+                history.At(o.t, headOwn);
+                auto pair = [](bool ok, float a, float b) {
+                    char p[48];
+                    if (!ok) return std::string("null");
+                    std::snprintf(p, sizeof p, "[%.4f,%.4f]", a, b);
+                    return std::string(p);
+                };
+                // Stored right eye first; reported left first, like the other sources.
+                const std::string extra = "\"age\":" + std::to_string(int((now - o.t) * 1000)) +
+                                          ",\"eyes\":[" + pair(o.flags & 2, o.eyes[2], o.eyes[3]) + "," +
+                                          pair(o.flags & 1, o.eyes[0], o.eyes[1]) + "],\"slip\":[" +
+                                          pair(o.flags & 8, o.slip[2], o.slip[3]) + "," +
+                                          pair(o.flags & 4, o.slip[0], o.slip[1]) + "],";
+                // Where each eye's own gaze lands (left, right), for drawing them apart.
+                auto eyeHit = [&](bool ok, float y, float p) {
+                    return ok ? HitJson(list, headOwn, y, p) : std::string("null");
+                };
+                const std::string hits = "\"ehit\":[" + eyeHit(o.flags & 2, o.eyes[2], o.eyes[3]) + "," +
+                                         eyeHit(o.flags & 1, o.eyes[0], o.eyes[1]) + "],";
+                own = SrcJson(list, headOwn, Direction(o.yaw, o.pitch), extra + hits);
+            }
+
             double yaw, pitch;
             const Vec3 f = Rotate(headNow, {0, 0, -1});
             yaw = std::atan2(-f.x, -f.z) * 180 / M_PI;
             pitch = std::asin(std::clamp(f.y, -1.0, 1.0)) * 180 / M_PI;
             std::printf("{\"t\":%.5f,\"age\":%.1f,\"n\":%u,\"head\":{\"yaw\":%.4f,\"pitch\":%.4f,\"hit\":%s},"
-                        "\"src\":{\"action\":%s,\"mmap1\":%s,\"mmap2\":%s,\"left\":%s,\"right\":%s},\"eye\":%s}\n",
+                        "\"src\":{\"action\":%s,\"mmap1\":%s,\"mmap2\":%s,\"left\":%s,\"right\":%s,\"own\":%s},"
+                        "\"eye\":%s}\n",
                         s.t, (now - s.t) * 1000, s.n, yaw, pitch, HitJson(list, headNow, 0, 0).c_str(), action.c_str(),
-                        m1.c_str(), m2.c_str(), left.c_str(), right.c_str(), eye.c_str());
+                        m1.c_str(), m2.c_str(), left.c_str(), right.c_str(), own.c_str(), eye.c_str());
             if (std::fflush(stdout) != 0) break;  // the reader went away
         }
 

gaze/probe/ft-gazeprobe

@@ -60,6 +60,7 @@ import math
 import os
 import random
 import signal
+import socket
 import statistics
 import subprocess
 import sys
@@ -78,15 +79,44 @@ REPO = Path(__file__).resolve().parents[2]
 HELPER = REPO / "gaze" / "build" / "ft-gaze"
 STATE = Path.home() / ".local" / "state" / "frametop" / "gaze"
 # left and right: each eye alone (set 2's own reading of that eye), calibrated and tested
-# like the rest, to see what one eye is worth against both.
-SOURCES = ["action", "mmap1", "mmap2", "left", "right"]
+# like the rest, to see what one eye is worth against both. own: our own tracker
+# (~/Desktop/Projects/frame-eyes, fe-trackd), when it's running; it has its own calibration.
+SOURCES = ["action", "mmap1", "mmap2", "left", "right", "own"]
 SOURCE_NAMES = {"action": "SteamVR action", "mmap1": "mmap set 1", "mmap2": "mmap set 2", "left": "Left eye",
-                "right": "Right eye"}
+                "right": "Right eye", "own": "Own tracker"}
 SOURCE_COLORS = {"action": (0.2, 0.8, 1.0), "mmap1": (1.0, 0.6, 0.1), "mmap2": (0.9, 0.3, 0.9),
-                 "left": (0.4, 1.0, 0.6), "right": (1.0, 1.0, 0.4)}
+                 "left": (0.4, 1.0, 0.6), "right": (1.0, 1.0, 0.4), "own": (1.0, 0.35, 0.35)}
 TRIGGER_KEYS = {Gdk.KEY_Return, Gdk.KEY_KP_Enter, Gdk.KEY_space}
 
 
+class OwnTracker:
+    """Talks to our own tracker (frame-eyes fe-trackd) over its control socket (@frame_eyes).
+    It keeps its own calibration: the probe sends it calibration dots and clicks, each with
+    when you looked and where (head-relative degrees), and it learns from its own frames."""
+
+    def __init__(self):
+        self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+        self.sock.bind(f"\0ft_gazeprobe.{os.getpid()}")
+        self.sock.settimeout(1.0)
+
+    def ask(self, command):
+        """The reply line, or "fail ..." if the tracker isn't running or doesn't answer."""
+        try:
+            while True:  # drop a late reply to an earlier command
+                self.sock.setblocking(False)
+                self.sock.recv(4096)
+        except (BlockingIOError, OSError):
+            pass
+        self.sock.settimeout(1.0)
+        try:
+            self.sock.sendto(command.encode(), "\0frame_eyes")
+            return self.sock.recv(4096).decode()
+        except (ConnectionRefusedError, FileNotFoundError):
+            return "fail the Own tracker isn't running (frame-eyes: tools/fe-live)"
+        except (socket.timeout, OSError) as e:
+            return f"fail no answer from the Own tracker ({e})"
+
+
 # The math, filters, correction models, and SteamVR log reader are shared with ft-gazed.
 sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
 from gazecal import (DEFAULT_MODEL, MODELS, Correction, Fixation, LiveCorrection, OneEuro,  # noqa: E402
@@ -427,6 +457,7 @@ class Probe(Adw.ApplicationWindow):
         self.fitcheck = FitCheck()      # Headset fit: how well the tracker sees each eye
 
         self.models = {s: Correction() for s in SOURCES}
+        self.own = OwnTracker()
         self.live = {s: LiveCorrection() for s in SOURCES}
         self.steam = SteamEyeLog()
         self.steam.poll()
@@ -704,12 +735,22 @@ class Probe(Adw.ApplicationWindow):
             grid.attach(widget, 1, row, 1, 1)
             row += 1
 
+        # Which tracker drives the dot. SteamVR's gaze is still logged in the background with
+        # the Own tracker (for comparing), but not shown.
+        tracker = Gtk.Box(css_classes=["linked"])
+        self.w_steamvr = Gtk.ToggleButton(label="SteamVR", active=True)
+        self.w_own = Gtk.ToggleButton(label="Own tracker", group=self.w_steamvr)
+        tracker.append(self.w_steamvr)
+        tracker.append(self.w_own)
+        self.w_own.connect("toggled", lambda b: self.on_tracker())
+        add("Tracker", tracker)
         self.w_screen = self.dropdown(["Screen 1"])
         add("Screen", self.w_screen)
         self.w_mode = self.dropdown(self.MODE_NAMES)
         add("Mode", self.w_mode)
         # mmap set 2 had the least jitter (0.25 deg vs 0.30 for the action, sitting still).
         self.w_source = self.dropdown([SOURCE_NAMES[s] for s in SOURCES], 2)
+        self.w_source.connect("notify::selected", lambda *_: self.sync_tracker())
         add("Source", self.w_source)
         self.w_filter = self.dropdown(["Raw", "One Euro", "Fixation lock"], 2)
         add("Smoothing", self.w_filter)
@@ -866,6 +907,25 @@ class Probe(Adw.ApplicationWindow):
         n = len(self.live[self.source].samples)
         return self.model_mode + (f" + {n} clicks" if n and self.w_snaps.get_active() else "")
 
+    def on_tracker(self):
+        """The tracker toggle: the Own tracker, or SteamVR's set 2 (its quietest source)."""
+        own = self.w_own.get_active()
+        if own != (self.source == "own"):
+            self.w_source.set_selected(SOURCES.index("own") if own else SOURCES.index("mmap2"))
+        if own:
+            reply = self.own.ask("status")
+            if reply.startswith("fail"):
+                self.on_status(reply[5:])
+            else:
+                st = json.loads(reply)
+                self.on_status("Own tracker: " + ("calibrated " + st["calibration"].get("made", "")
+                                                  if st.get("calibration") else "not calibrated yet: Run calibration"))
+
+    def sync_tracker(self):
+        own = self.source == "own"
+        if self.w_own.get_active() != own:
+            (self.w_own if own else self.w_steamvr).set_active(True)
+
     def on_setting(self):
         model = self.model_mode
         if model != getattr(self, "last_model", model):
@@ -991,6 +1051,9 @@ class Probe(Adw.ApplicationWindow):
         head = s["head"].get("hit")
         ox, oy = self.origin or (0, 0)
         self.head = (head["x"] - ox, head["y"] - oy) if head and head["s"] == self.screen else None
+        # The Own tracker's eyes, each where it alone puts your gaze (left, right).
+        self.own_eyes = [(h["x"] - ox, h["y"] - oy) if h and h["s"] == self.screen else None
+                         for h in ((s["src"].get("own") or {}).get("ehit") or [])]
 
         r = self.raw.get(self.source)
         if r is None:
@@ -1025,7 +1088,10 @@ class Probe(Adw.ApplicationWindow):
 
     def correction(self, name, hy, hp, snaps=None):
         """The whole correction at (hy, hp): the calibration, plus what snap and practice
-        clicks have taught since (when "Learn from clicks" is on)."""
+        clicks have taught since (when "Learn from clicks" is on). None for the Own tracker:
+        it learns from the clicks itself (own_click)."""
+        if name == "own":
+            return 0.0, 0.0
         cy, cp = self.models[name].get(hy, hp, self.model_mode)
         if snaps if snaps is not None else self.w_snaps.get_active():
             ly, lp = self.live[name].get(hy, hp)
@@ -1263,7 +1329,7 @@ class Probe(Adw.ApplicationWindow):
             self.on_status("no gaze on this screen at the press")
             return
         self.practice = {"t": time.monotonic(), "F": self.gaze, "fix": fix, "pointer0": self.pointer,
-                         "target": self.targets[0]}
+                         "target": self.targets[0], "t_raw": self.recent[-1]["t"] if self.recent else None}
         self.area.queue_draw()
 
     def practice_point(self):
@@ -1304,6 +1370,13 @@ class Probe(Adw.ApplicationWindow):
             # You were looking at the release point when you pressed: from the raw gaze to
             # it is the whole error there.
             oy, op = deg_from_px(fix["j"], px - fix["x"], py - fix["y"])
+            if name == "own":
+                rec["sources"][name] = {"hy": fix["hy"], "hp": fix["hp"], "raw": [fix["x"], fix["y"]],
+                                        "off": [oy, op], "n": fix["n"]}
+                if self.source == "own":
+                    rec["own"] = self.own_click(p, fix["hy"] + oy, fix["hp"] + op, math.hypot(oy, op))
+                    verdict = rec["own"]
+                continue
             c = self.correction(name, fix["hy"], fix["hp"], snaps=True)
             left = math.hypot(oy - c[0], op - c[1])
             rec["sources"][name] = {"hy": fix["hy"], "hp": fix["hp"], "raw": [fix["x"], fix["y"]], "off": [oy, op],
@@ -1320,7 +1393,7 @@ class Probe(Adw.ApplicationWindow):
         if learn:
             self.save_calibration()
         rec["verdict"] = verdict
-        rec["learned"] = verdict == "learned"
+        rec["learned"] = verdict == "learned" or verdict.startswith("taught")
         self.attempts.append(rec)
         self.log("practice.jsonl", rec)
         # Drawn for a moment: the drag, from where the gaze put the pointer to where you let go.
@@ -1330,6 +1403,19 @@ class Probe(Adw.ApplicationWindow):
         self.new_target()
         self.update_stats()
 
+    def own_click(self, p, yaw, pitch, off):
+        """Teach the Own tracker: you were looking at (yaw, pitch) just before the press.
+        Every click counts, dragged or not (a click that needed no drag says so too), unless
+        the drag was too far to be the tracker's error."""
+        if not self.w_snaps.get_active():
+            return "clicked (learning is off)"
+        if off > self.SNAP_LEARN_MAX:
+            return f"dragged {off:.1f} deg: too far to be the tracker's error, not learned"
+        if p.get("t_raw") is None:
+            return "no sample time at the press"
+        reply = self.own.ask(f"click {p['t_raw']:.6f} {yaw:.4f} {pitch:.4f}")
+        return "taught the Own tracker" if reply.startswith("ok") else reply
+
     def on_motion(self, x, y):
         self.pointer = (x, y)
         if self.practice:
@@ -1551,6 +1637,13 @@ class Probe(Adw.ApplicationWindow):
                 best, best_cost = k, cost
         return best
 
+    @staticmethod
+    def steady_for(name, samples):
+        """steady_samples, but for the Own tracker its own view of the eyes, not SteamVR's."""
+        if name != "own":
+            return steady_samples(samples)
+        return [smp for smp in samples if all((smp["src"].get("own") or {}).get("eyes") or [None])]
+
     def press_fixation(self, name):
         """Where `name` put your gaze just before the press: the median of the last 300 ms,
         without blinks, dropouts, or samples from before an eye movement in that time."""
@@ -1559,7 +1652,7 @@ class Probe(Adw.ApplicationWindow):
         t_end = self.recent[-1]["t"]
         pts = []
         ox, oy = self.origin or (0, 0)
-        for smp in steady_samples([smp for smp in self.recent if smp["t"] >= t_end - 0.3]):
+        for smp in self.steady_for(name, [smp for smp in self.recent if smp["t"] >= t_end - 0.3]):
             src = smp["src"].get(name) or {}
             hit = src.get("hit")
             if hit and hit["s"] == self.screen:
@@ -1746,6 +1839,13 @@ class Probe(Adw.ApplicationWindow):
         return pts
 
     def start_calibration(self):
+        if self.source == "own":
+            # A fresh calibration for the Own tracker: it forgets the old one's clicks and
+            # shifts when this one is fitted.
+            reply = self.own.ask("calib-start")
+            if reply.startswith("fail"):
+                self.on_status(reply[5:])
+                return
         self.test = None
         self.results = None
         self.capture = None
@@ -1808,7 +1908,9 @@ class Probe(Adw.ApplicationWindow):
                    "sources": {n: {k: g[k] for k in ("err_deg", "sd_deg", "off_deg", "mean", "n")}
                                for n, g in entry["sources"].items()}}
         verdict = None
-        if not mine:
+        if self.source == "own":
+            verdict = self.own_calib_point(c["samples"], target)
+        elif not mine:
             if len(steady) < 20:
                 verdict = (f"only {len(steady)} of {len(c['samples'])} samples had both eyes tracked "
                            "(blinks, or the tracker lost an eye): open your eyes wide and press again")
@@ -1830,11 +1932,39 @@ class Probe(Adw.ApplicationWindow):
             c["retry"] = verdict + (" (S skips this dot)" if c["tries"] >= 2 else "")
             return
         c["tries"] = 0
+        if mine:
             c.setdefault("seen", {})[c["index"]] = tuple(mine["mean"])
         c["data"].append(entry)
         c["done_at"] = now  # a short pause on the filled dot, then the next one
         GLib.timeout_add(350, self.calib_next)
 
+    def own_calib_point(self, samples, target):
+        """Send one calibration dot to the Own tracker: the time you looked at it and its
+        direction. The direction comes from the screen geometry around it, through SteamVR's
+        nearby gaze and its pixels-per-degree there (only the geometry is used, not where
+        SteamVR thinks you looked). None if accepted, else why not."""
+        pts = []
+        ox, oy = self.origin or (0, 0)
+        for smp in samples:
+            for name in ("mmap1", "mmap2", "action"):
+                src = smp["src"].get(name) or {}
+                hit = src.get("hit")
+                if hit and hit["s"] == self.screen:
+                    pts.append((hit["x"] - ox, hit["y"] - oy, hit["j"], src["hy"], src["hp"]))
+                    break
+        if len(pts) < 5 or len(samples) < 2:
+            return "no gaze samples on this screen: look at the dot and press again"
+        x = statistics.median(q[0] for q in pts)
+        y = statistics.median(q[1] for q in pts)
+        j = [statistics.fmean(q[2][k] for q in pts) for k in range(4)]
+        oy_, op_ = deg_from_px(j, target[0] - x, target[1] - y)
+        yaw = statistics.median(q[3] for q in pts) + oy_
+        pitch = statistics.median(q[4] for q in pts) + op_
+        reply = self.own.ask(f"calib-point {samples[0]['t']:.6f} {samples[-1]['t']:.6f} {yaw:.4f} {pitch:.4f}")
+        if reply.startswith("ok"):
+            return None
+        return reply[5:] + ": look at the dot and press again"
+
     def other_dot(self, c, g):
         """Was the gaze on another dot of this round rather than the current one?
 
@@ -1899,17 +2029,22 @@ class Probe(Adw.ApplicationWindow):
         self.test_history = []
         self.log_points("calibration", data)
         self.save_calibration()
+        own_note = ""
+        if self.source == "own":
+            reply = self.own.ask("calib-fit")
+            own_note = ("Own tracker: " + reply[3:]) if reply.startswith("ok") else ("Own tracker: " + reply)
+            print(f"calibration: {own_note}", file=sys.stderr, flush=True)
         if self.model_mode == "none":
             self.last_model = mode  # just fitted
             self.w_model.set_selected(MODELS.index(mode))
         if self.w_autotest.get_active():
             # The check on spots the calibration hasn't seen, right away: same head
             # position, same session of SteamVR's own calibration.
-            self.on_status(f"calibrated ({mode}) from {len(data)} dots; now testing it on new spots")
+            self.on_status(f"calibrated ({mode}) from {len(data)} dots; now testing it on new spots. {own_note}")
             GLib.timeout_add(1500, lambda: (self.start_test(), False)[1])
         else:
             self.panel.set_visible(True)
-            self.on_status(f"calibrated ({mode}) from {len(data)} dots; Start test to check it")
+            self.on_status(f"calibrated ({mode}) from {len(data)} dots; Start test to check it. {own_note}")
 
     def draw_calib(self, cr, w, h):
         c = self.calib
@@ -2386,7 +2521,8 @@ class Probe(Adw.ApplicationWindow):
 
         frozen = self.capture is not None
         live = not frozen or self.w_live.get_active()
-        if self.w_all.get_active() and live:
+        own = self.source == "own"
+        if self.w_all.get_active() and live and not own:
             for name in SOURCES:
                 rr = self.raw.get(name)
                 if rr:
@@ -2403,7 +2539,14 @@ class Probe(Adw.ApplicationWindow):
                 cr.move_to(x, y - 12)
                 cr.line_to(x, y + 12)
                 cr.stroke()
-        if self.w_rawdot.get_active() and r and live:
+        if self.w_rawdot.get_active() and own and live:
+            # Each eye alone: they should meet, with a little jitter, where you look.
+            for e in getattr(self, "own_eyes", []):
+                if e:
+                    cr.set_source_rgba(1, 0.25, 0.25, 0.85)
+                    cr.arc(e[0], e[1], 5, 0, 2 * math.pi)
+                    cr.fill()
+        elif self.w_rawdot.get_active() and r and live:
             cr.set_source_rgba(1, 0.3, 0.3, 0.8)
             cr.arc(r[0], r[1], 5, 0, 2 * math.pi)
             cr.fill()
@@ -2425,7 +2568,7 @@ class Probe(Adw.ApplicationWindow):
         res = self.result
         if res and now - res["shown"] < 2.5 and "L" in res:
             a = max(0.0, 1 - (now - res["shown"]) / 2.5)
-            ok = res["verdict"] == "learned" or res["verdict"] == "measured"
+            ok = res["verdict"] in ("learned", "measured") or res["verdict"].startswith("taught")
             (fx, fy), (lx, ly) = res["F"], res["L"]
             cr.set_source_rgba(*((1, 0.85, 0.2) if ok else (1, 0.35, 0.3)), a)
             cr.set_line_width(2)
@@ -2603,12 +2746,15 @@ def main():
     ap = argparse.ArgumentParser(description="Eye tracking playground for the Frametop desktop")
     ap.add_argument("--screen", type=int, default=0, help="Frametop screen to open on (default: where it opens)")
     ap.add_argument("--mode", choices=Probe.MODE_KEYS, help="start in this mode (fit: Headset fit)")
+    ap.add_argument("--source", choices=SOURCES, help="gaze source to start with (default: mmap2)")
     args, rest = ap.parse_known_args()
     app = Adw.Application(application_id="dev.frametop.GazeProbe", flags=Gio.ApplicationFlags.NON_UNIQUE)
     windows = []
 
     def activate(a):
         win = Probe(a, args.screen)
+        if args.source:
+            win.w_source.set_selected(SOURCES.index(args.source))
         if args.mode:
             win.set_mode(args.mode)
         windows.append(win)