Files
DeeJanuz--frametop/hands/track/pinch.cpp
T
DeeJanuzandClaude Opus 5.5 50c14545ed Hands: pick the cameras by the light, and detect grips
ft-hands tracks with the mono IR cameras in dim light and with every
camera (or the colour pair, HANDS_BRIGHT) in bright light, going by the
colour frames' mean brightness with hysteresis and a 2 s hold
(HANDS_CAMERAS=auto, the default; mono, color and all fix it). Colour
frames are placed on the mono cameras' clock by their dequeue time, and a
view in a camera a step lacks waits for that camera's next frame.

A grip (a closed hand) is a second gesture next to the pinch, in version 2
of the gestures file: every fingertip curled toward the wrist, beginning
only on a hand seen open within a second and held up in front. On the
2026-09-30 lit recording that leaves 6 false grips of 14, all with the
hands on the desk; pinch counts are unchanged. ft-handreplay logs grips
and finger curl, watch_gestures.py shows them, and tools/cut_sets.py
copies a few sets out of a recording.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-30 14:31:17 -06:00

300 lines
12 KiB
C++

#include "pinch.h"
#include "io.h"
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include <algorithm>
#include <cerrno>
#include <cstdlib>
#include <cstring>
namespace {
constexpr int kThumbTip = 4, kIndexTip = 8;
V3 cross(V3 a, V3 b) { return {a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]}; }
void put3(float out[3], V3 v) {
for (int k = 0; k < 3; ++k) out[k] = float(v[k]);
}
} // namespace
void Pinch::update(const std::vector<const Hand *> &hands, const std::vector<Seen> &views, int64_t t_ns,
const std::vector<int> &gripping) {
events.clear();
auto grips = [&](int id) { return std::find(gripping.begin(), gripping.end(), id) != gripping.end(); };
for (int s = 0; s < 2; ++s) // a grip took this pinch's hand: it's a drag now, not a click
if ((side_[s].flags & FH_PINCH_DOWN) && grips(follow_[s])) end(s, t_ns, true);
// A hand a pinch is down on belongs to that side until it ends. The left/right call is a
// running average of the model's, and when it flips mid-pinch the other side would take
// the same hand and pinch too (4 times in the 2026-09-30 lit recording).
int taken[2] = {0, 0};
for (int s = 0; s < 2; ++s)
if (side_[s].flags & FH_PINCH_DOWN) taken[s] = follow_[s];
for (int s = 0; s < 2; ++s) {
fh_pinch_t &o = side_[s];
const bool down = o.flags & FH_PINCH_DOWN;
// the hand: while down, the one the pinch began on; else the best tracked hand of this side
const Hand *h = nullptr;
for (const Hand *c : hands) {
if (down ? c->id != follow_[s] : c->right() != (s == 1) || c->id == taken[1 - s]) continue;
if (!h || c->frames > h->frames) h = c;
}
world_d[s] = tri_d[s] = palm_down[s] = -1;
if (!h) {
o.flags &= ~FH_PINCH_TRACKED;
if (down && (t_ns - seen_ns_[s]) / 1e9 > p_.grace_s) end(s, t_ns, true);
continue;
}
seen_ns_[s] = t_ns;
tri_d[s] = norm(h->pts[kThumbTip] - h->pts[kIndexTip]);
const V3 normal = cross(h->smooth[5] - h->smooth[0], h->smooth[17] - h->smooth[0]);
palm_down[s] = norm(normal) > 0 ? std::fabs(normal[1]) / norm(normal) : 0;
double sum = 0;
int n = 0;
for (const Seen &v : views) {
if (v.hand != h->id) continue;
const V3 a{v.lm.world[kThumbTip][0], v.lm.world[kThumbTip][1], v.lm.world[kThumbTip][2]};
const V3 b{v.lm.world[kIndexTip][0], v.lm.world[kIndexTip][1], v.lm.world[kIndexTip][2]};
sum += norm(a - b), ++n;
}
if (n) world_d[s] = sum / n * h->scale;
const double d = p_.triangulated || world_d[s] < 0 ? tri_d[s] : world_d[s];
const V3 point = (h->smooth[kThumbTip] + h->smooth[kIndexTip]) * 0.5;
o.flags |= FH_PINCH_TRACKED;
o.hand_id = uint32_t(h->id);
o.distance = float(d);
o.strength = float(std::clamp((p_.end_m - d) / (p_.end_m - p_.begin_m), 0.0, 1.0));
put3(o.point, point);
if (!down) {
// a close held back (palm down) has to open again before a pinch can begin, so
// turning the hand with the fingers still closed doesn't start one
if (d > p_.end_m) held_[s] = false;
if (grips(h->id)) {
// closed: no pinch until it opens
} else if (d < p_.begin_m && !held_[s] && palm_down[s] > p_.palm_down_max) {
held_[s] = true;
++held_back[s];
} else if (d < p_.begin_m && !held_[s]) {
o.flags = (o.flags | FH_PINCH_DOWN) & ~FH_PINCH_LOST;
++o.begins;
o.begin_ns = uint64_t(t_ns);
put3(o.begin_point, point);
follow_[s] = h->id;
open_frames_[s] = 0;
events.push_back({s, "begin", t_ns, d, point});
}
} else if (d > p_.end_m) {
if (++open_frames_[s] >= p_.end_frames) end(s, t_ns, false);
} else {
open_frames_[s] = 0;
}
}
}
void Pinch::end(int s, int64_t t_ns, bool lost) {
fh_pinch_t &o = side_[s];
o.flags = (o.flags & ~FH_PINCH_DOWN) | (lost ? FH_PINCH_LOST : 0);
++o.ends;
o.end_ns = uint64_t(t_ns);
follow_[s] = 0;
events.push_back({s, lost ? "lost" : "end", t_ns, o.distance, {o.point[0], o.point[1], o.point[2]}});
}
void Pinch::release(int64_t t_ns) {
events.clear();
for (int s = 0; s < 2; ++s) {
side_[s].flags &= ~FH_PINCH_TRACKED;
if (side_[s].flags & FH_PINCH_DOWN) end(s, t_ns, true);
}
}
bool Pinch::engaged() const {
for (const fh_pinch_t &o : side_)
if ((o.flags & FH_PINCH_DOWN) || ((o.flags & FH_PINCH_TRACKED) && o.strength > 0.3f)) return true;
return false;
}
// ---------------------------------------------------------------------------- grip
namespace {
constexpr int kWrist = 0, kFingers[4][2] = {{5, 8}, {9, 12}, {13, 16}, {17, 20}}; // knuckle, tip
// Each finger's curl (see GripParams): from the model's world landmarks averaged over the
// hand's views this step, or the tracker's 3D points without any.
bool curls(const Hand &h, const std::vector<Seen> &views, double out[4]) {
double sum[4] = {};
int n = 0;
for (const Seen &v : views) {
if (v.hand != h.id) continue;
auto p = [&](int i) { return V3{v.lm.world[i][0], v.lm.world[i][1], v.lm.world[i][2]}; };
for (int f = 0; f < 4; ++f) {
const double k = norm(p(kFingers[f][0]) - p(kWrist));
sum[f] += k > 1e-4 ? norm(p(kFingers[f][1]) - p(kWrist)) / k : 2;
}
++n;
}
for (int f = 0; f < 4; ++f) {
if (n) {
out[f] = sum[f] / n;
continue;
}
const double k = norm(h.smooth[kFingers[f][0]] - h.smooth[kWrist]);
if (k < 1e-4) return false;
out[f] = norm(h.smooth[kFingers[f][1]] - h.smooth[kWrist]) / k;
}
return true;
}
V3 palm_centre(const Hand &h) {
return (h.smooth[0] + h.smooth[5] + h.smooth[9] + h.smooth[13] + h.smooth[17]) * 0.2;
}
} // namespace
void Grip::update(const std::vector<const Hand *> &hands, const std::vector<Seen> &views, int64_t t_ns) {
events.clear();
int taken[2] = {0, 0};
for (int s = 0; s < 2; ++s)
if (side_[s].flags & FH_PINCH_DOWN) taken[s] = follow_[s];
for (int s = 0; s < 2; ++s) {
fh_pinch_t &o = side_[s];
const bool down = o.flags & FH_PINCH_DOWN;
const Hand *h = nullptr;
for (const Hand *c : hands) {
if (down ? c->id != follow_[s] : c->right() != (s == 1) || c->id == taken[1 - s]) continue;
if (!h || c->frames > h->frames) h = c;
}
curl[s] = -1;
double f[4];
if (!h || !curls(*h, views, f)) {
o.flags &= ~FH_PINCH_TRACKED;
if (down && (t_ns - seen_ns_[s]) / 1e9 > p_.grace_s) end(s, t_ns, true);
continue;
}
seen_ns_[s] = t_ns;
const double mean = (f[0] + f[1] + f[2] + f[3]) / 4, most = std::max({f[0], f[1], f[2], f[3]});
curl[s] = mean;
const V3 point = palm_centre(*h);
o.flags |= FH_PINCH_TRACKED;
o.hand_id = uint32_t(h->id);
o.distance = float(mean);
o.strength = float(std::clamp((p_.end - mean) / (p_.end - p_.begin), 0.0, 1.0));
put3(o.point, point);
if (!down) {
if (mean > p_.end) open_ns_[s] = t_ns;
const bool ahead = -point[2] >= p_.min_ahead_m &&
std::atan2(-point[1], -point[2]) * 180 / M_PI <= p_.max_down_deg;
if (most < p_.begin && ahead && open_ns_[s] && (t_ns - open_ns_[s]) / 1e9 <= p_.armed_s) {
o.flags = (o.flags | FH_PINCH_DOWN) & ~FH_PINCH_LOST;
++o.begins;
o.begin_ns = uint64_t(t_ns);
put3(o.begin_point, point);
follow_[s] = h->id;
open_frames_[s] = 0;
events.push_back({s, "begin", t_ns, mean, point});
}
} else if (mean > p_.end) {
if (++open_frames_[s] >= p_.end_frames) {
end(s, t_ns, false);
open_ns_[s] = t_ns;
}
} else {
open_frames_[s] = 0;
}
}
}
void Grip::end(int s, int64_t t_ns, bool lost) {
fh_pinch_t &o = side_[s];
o.flags = (o.flags & ~FH_PINCH_DOWN) | (lost ? FH_PINCH_LOST : 0);
++o.ends;
o.end_ns = uint64_t(t_ns);
follow_[s] = 0;
events.push_back({s, lost ? "lost" : "end", t_ns, o.distance, {o.point[0], o.point[1], o.point[2]}});
}
void Grip::release(int64_t t_ns) {
events.clear();
for (int s = 0; s < 2; ++s) {
side_[s].flags &= ~FH_PINCH_TRACKED;
if (side_[s].flags & FH_PINCH_DOWN) end(s, t_ns, true);
}
}
std::vector<int> Grip::gripping() const {
std::vector<int> out;
for (int s = 0; s < 2; ++s)
if (side_[s].flags & FH_PINCH_DOWN) out.push_back(follow_[s]);
return out;
}
bool Grip::engaged() const {
for (const fh_pinch_t &o : side_)
if ((o.flags & FH_PINCH_DOWN) || ((o.flags & FH_PINCH_TRACKED) && o.strength > 0.3f)) return true;
return false;
}
// ----------------------------------------------------------------------- publisher
bool GesturePublisher::open(const Pinch &pinch, const Grip &grip, std::string &err) {
const std::string path = run_dir() + "/gestures";
const int fd = ::open(path.c_str(), O_RDWR | O_CREAT | O_NOFOLLOW | O_CLOEXEC, 0600);
if (fd < 0 || ftruncate(fd, sizeof(fh_gestures_t)) < 0) return err = path + ": " + std::strerror(errno), false;
void *m = mmap(nullptr, sizeof(fh_gestures_t), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
close(fd);
if (m == MAP_FAILED) return err = path + ": can't map it", false;
out_ = static_cast<fh_gestures_t *>(m);
// keep the counters a previous tracker left, so a reader doesn't see them jump back
const bool ours = !std::memcmp(out_->magic, FH_GESTURES_MAGIC, 8) && out_->version == FH_GESTURES_VERSION;
if (!ours) {
std::memset(out_, 0, sizeof *out_);
std::memcpy(out_->magic, FH_GESTURES_MAGIC, 8);
out_->version = FH_GESTURES_VERSION;
out_->size = sizeof(fh_gestures_t);
}
seq_ = out_->seq / 2 + 1;
// a gesture the last tracker left down (it crashed) is over: count its end, as lost
__atomic_store_n(&out_->seq, 2 * ++seq_ - 1, __ATOMIC_RELAXED);
__atomic_thread_fence(__ATOMIC_RELEASE);
for (fh_pinch_t *slots : {out_->pinch, out_->grip})
for (int s = 0; s < 2; ++s) {
fh_pinch_t &o = slots[s];
if (o.begins == o.ends) continue;
o.ends = o.begins;
o.end_ns = mono_ns();
o.flags = (o.flags & ~FH_PINCH_DOWN) | FH_PINCH_LOST;
}
__atomic_store_n(&out_->seq, 2 * seq_, __ATOMIC_RELEASE);
out_->begin_m = float(pinch.params().begin_m);
out_->end_m = float(pinch.params().end_m);
out_->grip_begin = float(grip.params().begin);
out_->grip_end = float(grip.params().end);
return true;
}
void GesturePublisher::write(const Pinch &pinch, const Grip &grip, uint64_t capture_ns) {
__atomic_store_n(&out_->seq, 2 * ++seq_ - 1, __ATOMIC_RELAXED);
__atomic_thread_fence(__ATOMIC_RELEASE);
for (int g = 0; g < 2; ++g)
for (int s = 0; s < 2; ++s) {
// counters carry on from what's in the file (a restarted tracker starts its own at 0)
const fh_pinch_t &in = g ? grip.side(s) : pinch.side(s);
fh_pinch_t &o = g ? out_->grip[s] : out_->pinch[s];
const uint32_t base_b = o.begins - last_begins_[g][s], base_e = o.ends - last_ends_[g][s];
o = in;
o.begins = base_b + in.begins;
o.ends = base_e + in.ends;
last_begins_[g][s] = in.begins, last_ends_[g][s] = in.ends;
}
out_->capture_ns = capture_ns;
out_->publish_ns = mono_ns();
__atomic_store_n(&out_->seq, 2 * seq_, __ATOMIC_RELEASE);
}