new-site/scripts/workers/services/ink_signature_plotter.py
justin 894d989445 Add portable Line-us pen-arm support to ink-signature pipeline
Adds a second machine class (small fan-shaped reach arm) alongside the
CR-10/AxiDraw rectangular-bed plotters, so wet signatures can be produced
while away from the home station.

ink_signature_plotter.py:
- PlotterConfig gains dialect (marlin|lineus) + name; new LineUsConfig
  (native units, pen height = per-move Z, reach annulus from shoulder pivot).
- Named machine profiles (cr10 default, axidraw, lineus) via load_profile().
- bed_mm_to_lineus_units(), check_reach() (annulus for lineus, rectangle for
  marlin), compute_jig_offset_for_box() (solves jig from the ACTUAL fitted ink
  extent so a wide cell line doesn't over-constrain a small arm).
- emit_gcode() dispatches to emit_marlin_gcode()/emit_lineus_gcode().
- send_lineus(): WiFi TCP 1337 (NUL-terminated, ok-acked) or USB serial,
  dry_run=True default (same gating as the CR-10 path).

ink_signature_cli.py: --profile, --solve-jig (auto-applies jig offset),
--lineus-host/--lineus-usb, reach-check that refuses to --plot out-of-reach
on Line-us.

Tests: 43 checks (was 30) covering profiles, reach check, jig solve, lineus
emitter, dry-run sender. Docs updated with profiles + portable workflow.
2026-06-07 03:45:46 -05:00

869 lines
34 KiB
Python

"""Pen-plotter ink-signature pipeline: captured strokes -> G-code (and preview).
The Standard (no-login) CMS filing path requires an ORIGINAL ink signature on
paper ("Stamped, faxed or copied signatures will not be accepted"). To produce a
genuine wet-ink signature from a signature captured online, we redraw the
provider's own stroke paths onto the printed form with a pen mounted on a 3-axis
motion system (a Creality CR-10 V2 here, but any Marlin/GRBL machine works).
This module is HARDWARE-INDEPENDENT and fully testable without a plotter:
strokes (normalized 0..1) <- esign_records.signature_vector
| fit into the signature anchor box (PDF points)
v
paper-space coordinates (mm) <- via PlotterConfig (bed origin + jig)
|
+--> emit_gcode() -> Marlin/GRBL G-code for the CR-10 (Z = pen lift)
+--> render_preview_svg()/_overlay_pdf() -> verify the strokes land on
the cert line WITHOUT any hardware (this is our correctness test)
Coordinate frames
-----------------
* Capture box: signature pad canvas, origin top-left, x/y in [0,1].
* PDF: points, origin bottom-left (matches reportlab + our signature anchors).
* Plotter bed: millimetres, origin at the machine's homed corner (front-left for
a CR-10). A paper jig fixes the sheet at a known offset from that corner, so
PDF (0,0) of the sheet maps to (jig_x_mm, jig_y_mm) on the bed.
The signature anchor box (x, y, w, h, page_w, page_h in PDF points) tells us
exactly where on the page the signature must land — the same anchors the digital
stamper consumes. We fit the captured strokes into that box (preserving aspect),
then translate everything into bed mm using the jig offset.
"""
from __future__ import annotations
import io
import math
from dataclasses import dataclass, field
from typing import Any
PT_PER_INCH = 72.0
MM_PER_INCH = 25.4
PT_TO_MM = MM_PER_INCH / PT_PER_INCH # 0.352777...
@dataclass(frozen=True)
class PlotterConfig:
"""Physical configuration of the pen plotter + paper jig.
Defaults target a Creality CR-10 V2 (300x300x400 bed) with a US-Letter sheet
held by a corner jig at the front-left of the bed. Tune jig_x_mm / jig_y_mm
and pen heights during calibration with the test-box routine.
Two control dialects are supported:
- "marlin" (default): Marlin/GRBL G-code in millimetres, pen up/down via Z
or M280 servo. For the CR-10 and AxiDraw-class machines.
- "lineus": the Line-us palm-size drawing arm. It speaks its own GCode in
its OWN units over a small, fan-shaped reach envelope, with the
pen height encoded as Z in each G01. See LineUsConfig.
The internal geometry pipeline always works in millimetres; the emitter for
each dialect converts at the end.
"""
# Control dialect: "marlin" or "lineus".
dialect: str = "marlin"
# Human label for the profile (e.g. "cr10", "axidraw", "lineus").
name: str = "cr10"
# Where PDF (0,0) — the sheet's bottom-left corner — sits on the bed, in mm
# from the machine's homed origin.
jig_x_mm: float = 20.0
jig_y_mm: float = 20.0
# Pen Z heights (mm). pen_down should be the height at which the pen touches
# paper; with a spring-loaded holder a small over-press is safe.
pen_up_mm: float = 3.0
pen_down_mm: float = 0.0
# Feed rates (mm/min).
travel_feed: float = 3000.0 # pen-up moves
draw_feed: float = 1200.0 # pen-down (drawing) moves
z_feed: float = 600.0 # pen raise/lower
# Bed safety envelope (mm). Emitter raises if a point would exceed these.
bed_max_x_mm: float = 300.0
bed_max_y_mm: float = 300.0
# Resampling: drop points closer than this (mm) to keep G-code compact and
# the pen smooth.
min_segment_mm: float = 0.3
# Pen-up/down via BLTouch/servo instead of Z (set servo_pen=True to emit
# M280 deploy/stow instead of G1 Z moves — useful if you mount the pen to a
# servo or repurpose the BLTouch as the actuator).
servo_pen: bool = False
servo_index: int = 0
servo_down_angle: int = 10
servo_up_angle: int = 90
# Line-us mapping (only used when dialect == "lineus").
lineus: "LineUsConfig | None" = None
@dataclass(frozen=True)
class LineUsConfig:
"""Maps bed millimetres to the Line-us arm's native coordinate space.
The Line-us is a small 2-link arm that draws with a real pen. It accepts
GCode (G01 X Y Z, G28 home) but in its OWN units over a fan-shaped reach,
NOT millimetres, and the pen height is the Z value in each move (low Z =
pen down, high Z = pen up). Its usable area is roughly a half-disc in front
of the shoulder pivot.
We model the reachable area as: distance from the shoulder pivot (in Line-us
units) must lie within [reach_min, reach_max], and we affine-map bed mm to
Line-us units with a uniform scale + origin. Because the work area is small,
the paper jig must place the signature cell inside reach — check_reach()
verifies this BEFORE plotting and the jig calculator helps position the form.
Defaults follow the documented Line-us envelope (X ~700..1775, Y ~-1000..1000,
Z pen 0=down .. 1000=up). units_per_mm is the conversion derived from the
arm's ~A6 usable width.
"""
units_per_mm: float = 13.0 # Line-us units per millimetre on the page
origin_x_units: float = 1000.0 # Line-us X where the jig's bed-origin sits
origin_y_units: float = 0.0 # Line-us Y where the jig's bed-origin sits
pen_down_z: int = 0 # Z value for pen on paper
pen_up_z: int = 1000 # Z value for pen lifted
# Reach envelope, measured from the shoulder pivot at Line-us (0,0), in units.
shoulder_x_units: float = 0.0
shoulder_y_units: float = 0.0
reach_min_units: float = 700.0
reach_max_units: float = 2000.0
feed: int = 0 # Line-us ignores F; kept for parity
@dataclass
class PlannedStroke:
"""A single pen-down polyline in bed mm (one continuous pen contact)."""
points_mm: list[tuple[float, float]] = field(default_factory=list)
# ── Built-in machine profiles ────────────────────────────────────────────────
#
# Named presets so the home CR-10 and a portable Line-us are both first-class.
# Geometry/jig values are starting points; calibrate per device with --test-box.
def _profile_cr10() -> PlotterConfig:
"""Home station: Creality CR-10 V2 with a corner jig (Marlin, Z pen-lift)."""
return PlotterConfig(dialect="marlin", name="cr10")
def _profile_axidraw() -> PlotterConfig:
"""Portable A4 pen plotter (AxiDraw/iDraw class): Marlin/GRBL with a servo lift."""
return PlotterConfig(
dialect="marlin", name="axidraw",
bed_max_x_mm=210.0, bed_max_y_mm=297.0,
servo_pen=True, servo_up_angle=70, servo_down_angle=30,
jig_x_mm=10.0, jig_y_mm=10.0,
)
def _profile_lineus() -> PlotterConfig:
"""Pocket station: Line-us folding pen-arm (own GCode/units, small reach).
The arm's reach is small, so the jig must place the signature cell in the
sweet spot — use compute_jig_offset_for_box() (the CLI --solve-jig does this)
to get jig_x_mm/jig_y_mm for a given form before plotting.
"""
return PlotterConfig(
dialect="lineus", name="lineus",
# mm bookkeeping is still used internally; reach is enforced in Line-us units.
bed_max_x_mm=150.0, bed_max_y_mm=150.0,
jig_x_mm=0.0, jig_y_mm=0.0,
lineus=LineUsConfig(),
)
PROFILES: dict[str, "callable[[], PlotterConfig]"] = {
"cr10": _profile_cr10,
"axidraw": _profile_axidraw,
"lineus": _profile_lineus,
}
def load_profile(name: str) -> PlotterConfig:
"""Return a PlotterConfig for a named profile (cr10 | axidraw | lineus)."""
key = (name or "cr10").lower()
if key not in PROFILES:
raise ValueError(f"unknown plotter profile '{name}'; choices: {sorted(PROFILES)}")
return PROFILES[key]()
# ── Geometry: strokes (0..1) -> fitted PDF points -> bed mm ──────────────────
def _vector_bbox(strokes: list[list[dict]]) -> tuple[float, float, float, float]:
"""Bounding box (minx, miny, maxx, maxy) of normalized strokes."""
xs = [p["x"] for s in strokes for p in s]
ys = [p["y"] for s in strokes for p in s]
if not xs:
return 0.0, 0.0, 1.0, 1.0
return min(xs), min(ys), max(xs), max(ys)
def fit_strokes_to_box(
vector: dict,
box: dict,
*,
h_pad_frac: float = 0.04,
v_pad_frac: float = 0.12,
baseline_lift_pt: float = 1.5,
) -> list[list[tuple[float, float]]]:
"""Fit normalized capture strokes into the anchor box, in PDF points.
Returns a list of strokes; each stroke is a list of (x_pt, y_pt) with the
PDF convention (origin bottom-left). Aspect ratio is preserved, the ink is
left-aligned and rests just above the box bottom (the signature rule), and
the capture's top-left origin is flipped to PDF's bottom-left.
"""
strokes = (vector or {}).get("strokes") or []
if not strokes:
return []
minx, miny, maxx, maxy = _vector_bbox(strokes)
src_w = max(maxx - minx, 1e-6)
src_h = max(maxy - miny, 1e-6)
bx, by = float(box["x"]), float(box["y"])
bw, bh = float(box["w"]), float(box["h"])
avail_w = bw * (1.0 - 2 * h_pad_frac)
avail_h = bh * (1.0 - 2 * v_pad_frac)
# Scale to fit, preserving aspect ratio.
scale = min(avail_w / src_w, avail_h / src_h)
drawn_w = src_w * scale
drawn_h = src_h * scale
# Left-aligned within the box; bottom-anchored just above the rule.
off_x = bx + bw * h_pad_frac
off_y = by + baseline_lift_pt + (avail_h - drawn_h) * 0.0 # rest on baseline
out: list[list[tuple[float, float]]] = []
for s in strokes:
pts: list[tuple[float, float]] = []
for p in s:
nx = (p["x"] - minx) * scale
ny = (p["y"] - miny) * scale
x_pt = off_x + nx
# Flip Y: capture origin is top-left, PDF origin is bottom-left.
y_pt = off_y + (drawn_h - ny)
pts.append((x_pt, y_pt))
if pts:
out.append(pts)
return out
def pdf_points_to_bed_mm(
strokes_pt: list[list[tuple[float, float]]],
cfg: PlotterConfig,
) -> list[PlannedStroke]:
"""Translate fitted PDF-point strokes into bed millimetres via the jig offset."""
planned: list[PlannedStroke] = []
for s in strokes_pt:
mm = [
(cfg.jig_x_mm + x_pt * PT_TO_MM, cfg.jig_y_mm + y_pt * PT_TO_MM)
for (x_pt, y_pt) in s
]
mm = _resample(mm, cfg.min_segment_mm)
if mm:
planned.append(PlannedStroke(points_mm=mm))
return planned
def _resample(points: list[tuple[float, float]], min_seg_mm: float) -> list[tuple[float, float]]:
"""Drop points closer than min_seg_mm to the previous kept point."""
if not points:
return []
kept = [points[0]]
for p in points[1:]:
lx, ly = kept[-1]
if math.hypot(p[0] - lx, p[1] - ly) >= min_seg_mm:
kept.append(p)
if len(kept) == 1 and len(points) > 1:
kept.append(points[-1])
return kept
def plan_signature(vector: dict, box: dict, cfg: PlotterConfig) -> list[PlannedStroke]:
"""Full geometry pipeline: normalized strokes + anchor box -> bed-mm strokes."""
fitted = fit_strokes_to_box(vector, box)
return pdf_points_to_bed_mm(fitted, cfg)
# ── Line-us coordinate mapping + reach checking ──────────────────────────────
#
# The Line-us arm has a small, fan-shaped reach. Bed-mm coordinates (the same
# internal representation every dialect uses) are affine-mapped to Line-us units
# with a uniform scale + origin, then reach-checked against the shoulder pivot.
def bed_mm_to_lineus_units(x_mm: float, y_mm: float, lu: LineUsConfig) -> tuple[float, float]:
"""Map a bed-mm point to Line-us native units."""
return (
lu.origin_x_units + x_mm * lu.units_per_mm,
lu.origin_y_units + y_mm * lu.units_per_mm,
)
def _lineus_reach_ok(ux: float, uy: float, lu: LineUsConfig) -> bool:
"""True if a Line-us-unit point lies within the arm's reach annulus."""
d = math.hypot(ux - lu.shoulder_x_units, uy - lu.shoulder_y_units)
return lu.reach_min_units <= d <= lu.reach_max_units
def check_reach(planned: list[PlannedStroke], cfg: PlotterConfig) -> dict:
"""Verify EVERY planned point is reachable by the configured machine.
For "lineus" this checks the fan-shaped reach annulus; for "marlin" it checks
the rectangular bed envelope. Returns a report dict:
{ ok, dialect, total_points, out_of_reach, first_bad, min_d, max_d }
Call this BEFORE plotting so a tiny machine never tries to draw where it
cannot reach (which would distort the signature).
"""
pts = [(x, y) for s in planned for (x, y) in s.points_mm]
total = len(pts)
if cfg.dialect == "lineus":
lu = cfg.lineus or LineUsConfig()
bad = 0
first_bad: tuple[float, float] | None = None
dists: list[float] = []
for (x_mm, y_mm) in pts:
ux, uy = bed_mm_to_lineus_units(x_mm, y_mm, lu)
d = math.hypot(ux - lu.shoulder_x_units, uy - lu.shoulder_y_units)
dists.append(d)
if not (lu.reach_min_units <= d <= lu.reach_max_units):
bad += 1
if first_bad is None:
first_bad = (round(x_mm, 2), round(y_mm, 2))
return {
"ok": bad == 0,
"dialect": "lineus",
"total_points": total,
"out_of_reach": bad,
"first_bad": first_bad,
"min_d": round(min(dists), 1) if dists else None,
"max_d": round(max(dists), 1) if dists else None,
"reach": [lu.reach_min_units, lu.reach_max_units],
}
# marlin: rectangular bed
bad = 0
first_bad = None
for (x, y) in pts:
if x < 0 or y < 0 or x > cfg.bed_max_x_mm or y > cfg.bed_max_y_mm:
bad += 1
if first_bad is None:
first_bad = (round(x, 2), round(y, 2))
return {
"ok": bad == 0,
"dialect": "marlin",
"total_points": total,
"out_of_reach": bad,
"first_bad": first_bad,
"bed": [cfg.bed_max_x_mm, cfg.bed_max_y_mm],
}
def compute_jig_offset_for_box(
box: dict,
cfg: PlotterConfig,
*,
vector: dict | None = None,
margin_units: float = 50.0,
) -> dict:
"""For a small machine, find a jig offset that brings the signature into reach.
The signature box (PDF points) defines where ink must land on the sheet. On a
small arm we cannot reach an arbitrary page location, so we slide the paper
(i.e. choose jig_x_mm/jig_y_mm) until the signature sits in the sweet spot of
the reach annulus. This returns the recommended jig offset (mm) plus whether
the whole signature then fits.
When ``vector`` is given, we solve + reach-check against the ACTUAL fitted ink
extent (left-aligned, sub-cell) rather than the full cell rectangle. A full
cell line (e.g. CMS-855 spans ~422pt) is far wider than the real signature, so
using the ink extent is both more correct and far more likely to fit a small
arm. When ``vector`` is None we fall back to the whole-cell corners.
Strategy: aim the CENTRE of the (ink or cell) bbox at the mid-radius of the
reach annulus, straight ahead of the shoulder (uy = shoulder_y). Solve for the
jig offset that places it there, then reach-check the bbox corners.
"""
if cfg.dialect != "lineus":
return {"ok": True, "note": "Reach is rectangular; no jig solve needed.",
"jig_x_mm": cfg.jig_x_mm, "jig_y_mm": cfg.jig_y_mm}
lu = cfg.lineus or LineUsConfig()
# Determine the target bbox (PDF points): the actual ink extent if we have the
# vector, otherwise the full cell.
if vector and (vector.get("strokes")):
fitted = fit_strokes_to_box(vector, box)
ink_pts = [p for s in fitted for p in s]
if ink_pts:
bx = min(p[0] for p in ink_pts)
by = min(p[1] for p in ink_pts)
bw = max(p[0] for p in ink_pts) - bx
bh = max(p[1] for p in ink_pts) - by
else:
bx, by = float(box["x"]), float(box["y"])
bw, bh = float(box["w"]), float(box["h"])
else:
bx, by = float(box["x"]), float(box["y"])
bw, bh = float(box["w"]), float(box["h"])
# Centre of the target bbox in PDF points -> the bed-mm point we want at the
# annulus mid-radius, directly ahead of the shoulder.
cx_pt = bx + bw / 2.0
cy_pt = by + bh / 2.0
cx_mm_in_sheet = cx_pt * PT_TO_MM
cy_mm_in_sheet = cy_pt * PT_TO_MM
mid_r = (lu.reach_min_units + lu.reach_max_units) / 2.0
target_ux = lu.shoulder_x_units + mid_r
target_uy = lu.shoulder_y_units
# We need: origin + (jig + sheet_offset)*units_per_mm = target_units.
# => jig_mm = (target_units - origin_units)/units_per_mm - sheet_offset_mm
new_jig_x = (target_ux - lu.origin_x_units) / lu.units_per_mm - cx_mm_in_sheet
new_jig_y = (target_uy - lu.origin_y_units) / lu.units_per_mm - cy_mm_in_sheet
test_cfg = _replace_cfg(cfg, jig_x_mm=new_jig_x, jig_y_mm=new_jig_y)
# Reach-check: against the real fitted ink if we have it, else the cell corners.
if vector and (vector.get("strokes")):
check_planned = plan_signature(vector, box, test_cfg)
else:
corners_pt = [(bx, by), (bx + bw, by), (bx + bw, by + bh), (bx, by + bh)]
check_planned = pdf_points_to_bed_mm([corners_pt], test_cfg)
rep = check_reach(check_planned, test_cfg)
return {
"ok": rep["ok"],
"jig_x_mm": round(new_jig_x, 2),
"jig_y_mm": round(new_jig_y, 2),
"reach_report": rep,
"note": (
"Cell fits in reach with this jig offset."
if rep["ok"]
else "Cell does NOT fully fit; the machine's reach is too small for this "
"signature-cell size — reduce the cell or use a larger machine."
),
}
def _replace_cfg(cfg: PlotterConfig, **changes: Any) -> PlotterConfig:
"""Return a copy of cfg with fields overridden (frozen dataclass helper)."""
from dataclasses import replace
return replace(cfg, **changes)
# ── G-code emission (Marlin/GRBL) ────────────────────────────────────────────
def emit_gcode(planned: list[PlannedStroke], cfg: PlotterConfig) -> str:
"""Emit machine code for the configured dialect.
Dispatches to the Marlin/GRBL emitter (CR-10, AxiDraw) or the Line-us
emitter. Both consume the same bed-mm planned strokes; the per-dialect
converter runs at the end.
"""
if cfg.dialect == "lineus":
return emit_lineus_gcode(planned, cfg)
return emit_marlin_gcode(planned, cfg)
def emit_marlin_gcode(planned: list[PlannedStroke], cfg: PlotterConfig) -> str:
"""Emit Marlin/GRBL G-code that draws the planned strokes with the pen.
Assumes the machine is homed (G28) so (0,0) is the bed corner; the jig offset
is already baked into the planned coordinates. Pen up/down is done via Z
moves (default) or a servo/BLTouch M280 (cfg.servo_pen).
"""
out: list[str] = []
w = out.append
def pen_up():
if cfg.servo_pen:
w(f"M280 P{cfg.servo_index} S{cfg.servo_up_angle} ; pen up")
w("G4 P150")
else:
w(f"G1 Z{cfg.pen_up_mm:.2f} F{cfg.z_feed:.0f} ; pen up")
def pen_down():
if cfg.servo_pen:
w(f"M280 P{cfg.servo_index} S{cfg.servo_down_angle} ; pen down")
w("G4 P150")
else:
w(f"G1 Z{cfg.pen_down_mm:.2f} F{cfg.z_feed:.0f} ; pen down")
over_bed = any(
x > cfg.bed_max_x_mm or y > cfg.bed_max_y_mm or x < 0 or y < 0
for s in planned for (x, y) in s.points_mm
)
w("; --- Performance West ink-signature plot ---")
w("; CR-10 V2 / Marlin (or GRBL); machine assumed homed (G28) before this.")
if over_bed:
w("; !! WARNING: some points fall outside the configured bed envelope.")
w("G21 ; mm")
w("G90 ; absolute positioning")
pen_up()
for s in planned:
if not s.points_mm:
continue
x0, y0 = s.points_mm[0]
w(f"G0 X{x0:.3f} Y{y0:.3f} F{cfg.travel_feed:.0f} ; travel to stroke start")
pen_down()
for (x, y) in s.points_mm[1:]:
w(f"G1 X{x:.3f} Y{y:.3f} F{cfg.draw_feed:.0f}")
pen_up()
w("G0 X0 Y0 F{:.0f} ; park".format(cfg.travel_feed))
w("; --- end plot ---")
return "\n".join(out) + "\n"
def emit_lineus_gcode(planned: list[PlannedStroke], cfg: PlotterConfig) -> str:
"""Emit Line-us GCode for the planned strokes.
The Line-us speaks a GCode subset in its OWN units, where the pen height is
the Z value of each move (low Z = down, high Z = up). It acks each command
with "ok". We convert bed-mm to Line-us units, raise the pen between strokes,
and emit one G01 per point. A leading comment carries a reach warning if any
point falls outside the arm's envelope (call check_reach() to gate plotting).
"""
lu = cfg.lineus or LineUsConfig()
out: list[str] = []
w = out.append
def to_units(x_mm: float, y_mm: float) -> tuple[float, float]:
return bed_mm_to_lineus_units(x_mm, y_mm, lu)
report = check_reach(planned, cfg)
w("; --- Performance West ink-signature plot (Line-us) ---")
w("; Line-us native GCode; pen height is the Z value of each move.")
if not report["ok"]:
w(f"; !! WARNING: {report['out_of_reach']} of {report['total_points']} points "
f"fall outside the arm reach {report.get('reach')}. Re-jig the form "
f"(compute_jig_offset_for_box) before plotting.")
w("G28 ; home the arm")
# Start pen up at the first stroke's start to avoid a dragging line.
for s in planned:
if not s.points_mm:
continue
x0, y0 = s.points_mm[0]
ux0, uy0 = to_units(x0, y0)
# travel with pen up, then drop pen
w(f"G01 X{ux0:.0f} Y{uy0:.0f} Z{lu.pen_up_z:d} ; travel to stroke start (pen up)")
w(f"G01 X{ux0:.0f} Y{uy0:.0f} Z{lu.pen_down_z:d} ; pen down")
for (x, y) in s.points_mm[1:]:
ux, uy = to_units(x, y)
w(f"G01 X{ux:.0f} Y{uy:.0f} Z{lu.pen_down_z:d}")
# lift pen at end of stroke
lx, ly = s.points_mm[-1]
ulx, uly = to_units(lx, ly)
w(f"G01 X{ulx:.0f} Y{uly:.0f} Z{lu.pen_up_z:d} ; pen up")
# Park: pen up, return to a safe rest position ahead of the shoulder.
park_x = lu.shoulder_x_units + (lu.reach_min_units + lu.reach_max_units) / 2.0
w(f"G01 X{park_x:.0f} Y{lu.shoulder_y_units:.0f} Z{lu.pen_up_z:d} ; park")
w("; --- end plot ---")
return "\n".join(out) + "\n"
def emit_test_box_gcode(cfg: PlotterConfig, box: dict) -> str:
"""Emit G-code that draws the OUTLINE of the signature box (no signature).
Use this during calibration: tape a blank sheet in the jig, run this, and
confirm the rectangle lands exactly on the form's signature line. Adjust
jig_x_mm/jig_y_mm/pen heights until it does.
"""
bx, by = float(box["x"]), float(box["y"])
bw, bh = float(box["w"]), float(box["h"])
corners_pt = [(bx, by), (bx + bw, by), (bx + bw, by + bh), (bx, by + bh), (bx, by)]
planned = pdf_points_to_bed_mm([corners_pt], cfg)
return emit_gcode(planned, cfg)
# ── Serial sender (Marlin/GRBL over USB) — gated, dry-run safe ───────────────
def send_gcode_serial(
gcode: str,
port: str = "/dev/ttyUSB0",
baud: int = 115200,
*,
dry_run: bool = True,
home_first: bool = False,
line_timeout: float = 30.0,
) -> dict:
"""Stream G-code to a Marlin/GRBL controller over USB serial.
Defaults to ``dry_run=True`` so it never moves hardware unless explicitly
enabled — call with dry_run=False only when a sheet is loaded in the jig.
Marlin acks each line with "ok"; we wait for it before sending the next line
(simple, reliable flow control). Returns a summary dict.
"""
lines = [ln for ln in (l.strip() for l in gcode.splitlines())
if ln and not ln.startswith(";")]
if home_first:
lines = ["G28"] + lines
if dry_run:
return {
"sent": False, "dry_run": True, "port": port,
"lines": len(lines),
"note": "DRY RUN — no serial I/O. Set dry_run=False to plot.",
}
try:
import serial # pyserial
except ImportError as exc: # pragma: no cover
raise RuntimeError("pyserial is required to send G-code (pip install pyserial)") from exc
import time
ser = serial.Serial(port, baud, timeout=line_timeout)
try:
time.sleep(2.0) # board reset on connect
ser.reset_input_buffer()
sent = 0
for ln in lines:
ser.write((ln + "\n").encode("ascii"))
ser.flush()
# Wait for the controller's "ok" ack.
deadline = time.time() + line_timeout
while time.time() < deadline:
resp = ser.readline().decode("ascii", "ignore").strip().lower()
if resp.startswith("ok") or resp.startswith("done"):
break
if resp.startswith("error") or resp.startswith("!!"):
raise RuntimeError(f"controller error on '{ln}': {resp}")
sent += 1
return {"sent": True, "dry_run": False, "port": port, "lines": sent}
finally:
ser.close()
def send_lineus(
gcode: str,
*,
host: str = "line-us.local",
tcp_port: int = 1337,
serial_port: str | None = None,
baud: int = 115200,
dry_run: bool = True,
line_timeout: float = 30.0,
) -> dict:
"""Send Line-us GCode over WiFi (TCP 1337) or USB serial.
The Line-us connects over its own TCP socket (sends a "hello"/greeting on
connect) OR over USB serial, and acks each command with "ok". Defaults to
``dry_run=True`` so it never moves the arm unless explicitly enabled.
Pass serial_port to use USB instead of WiFi.
"""
lines = [ln for ln in (l.strip() for l in gcode.splitlines())
if ln and not ln.startswith(";")]
if dry_run:
return {
"sent": False, "dry_run": True,
"transport": "serial" if serial_port else "tcp",
"target": serial_port or f"{host}:{tcp_port}",
"lines": len(lines),
"note": "DRY RUN — no I/O. Set dry_run=False to plot.",
}
import time
def _wait_ok(read_line) -> None:
deadline = time.time() + line_timeout
while time.time() < deadline:
resp = read_line().decode("ascii", "ignore").strip().lower()
if resp.startswith("ok"):
return
if resp.startswith("error") or resp.startswith("!!"):
raise RuntimeError(f"Line-us error: {resp}")
raise RuntimeError("Line-us ack timeout")
if serial_port:
try:
import serial # pyserial
except ImportError as exc: # pragma: no cover
raise RuntimeError("pyserial required for USB (pip install pyserial)") from exc
ser = serial.Serial(serial_port, baud, timeout=line_timeout)
try:
time.sleep(2.0)
ser.reset_input_buffer()
sent = 0
for ln in lines:
ser.write((ln + "\n").encode("ascii"))
ser.flush()
_wait_ok(ser.readline)
sent += 1
return {"sent": True, "dry_run": False, "transport": "serial",
"target": serial_port, "lines": sent}
finally:
ser.close()
# WiFi: raw TCP socket.
import socket
sock = socket.create_connection((host, tcp_port), timeout=line_timeout)
sock.settimeout(line_timeout)
buf = b""
def _readline() -> bytes:
nonlocal buf
while b"\x00" not in buf and b"\n" not in buf:
chunk = sock.recv(256)
if not chunk:
break
buf += chunk
# Line-us terminates responses with a NUL byte.
sep = b"\x00" if b"\x00" in buf else b"\n"
if sep in buf:
line, _, buf = buf.partition(sep)
return line
line, buf = buf, b""
return line
try:
_readline() # consume the connect greeting
sent = 0
for ln in lines:
sock.sendall(ln.encode("ascii") + b"\x00")
_wait_ok(_readline)
sent += 1
return {"sent": True, "dry_run": False, "transport": "tcp",
"target": f"{host}:{tcp_port}", "lines": sent}
finally:
sock.close()
# ── Preview rendering (verify WITHOUT hardware) ──────────────────────────────
def render_preview_svg(
planned: list[PlannedStroke],
cfg: PlotterConfig,
*,
show_bed: bool = True,
) -> str:
"""Render the planned pen path as an SVG in bed mm (origin bottom-left).
Pen-down strokes are solid; pen-up travels are dashed grey. Lets us eyeball
the toolpath without a plotter.
"""
W = cfg.bed_max_x_mm
H = cfg.bed_max_y_mm
parts = [
f'<svg xmlns="http://www.w3.org/2000/svg" width="{W}mm" height="{H}mm" '
f'viewBox="0 0 {W} {H}">',
# Flip Y so bottom-left origin reads naturally.
f'<g transform="translate(0,{H}) scale(1,-1)">',
]
if show_bed:
parts.append(f'<rect x="0" y="0" width="{W}" height="{H}" fill="#fff" stroke="#ccc" stroke-width="0.5"/>')
prev_end: tuple[float, float] | None = None
for s in planned:
if not s.points_mm:
continue
if prev_end is not None:
x0, y0 = s.points_mm[0]
parts.append(
f'<line x1="{prev_end[0]:.2f}" y1="{prev_end[1]:.2f}" '
f'x2="{x0:.2f}" y2="{y0:.2f}" stroke="#bbb" stroke-width="0.2" '
f'stroke-dasharray="1,1"/>'
)
d = "M " + " L ".join(f"{x:.2f},{y:.2f}" for (x, y) in s.points_mm)
parts.append(f'<path d="{d}" fill="none" stroke="#10243f" stroke-width="0.6" stroke-linecap="round" stroke-linejoin="round"/>')
prev_end = s.points_mm[-1]
parts.append("</g></svg>")
return "\n".join(parts)
def render_signature_on_pdf(
pdf_bytes: bytes,
vector: dict,
anchors: list[dict],
*,
signer_field: str | None = None,
) -> bytes:
"""Stamp the VECTOR strokes onto the PDF at the anchor box(es).
This is the digital twin of what the pen will draw — same geometry path as
the plotter — so a visual diff against the real plotted sheet (or just an
eyeball of this PDF) proves the toolpath lands on the cert line. Returns a
flattened signed PDF.
"""
from pypdf import PdfReader, PdfWriter
from reportlab.pdfgen import canvas as rl_canvas
reader = PdfReader(io.BytesIO(pdf_bytes))
writer = PdfWriter()
# Group anchors by page.
by_page: dict[int, list[dict]] = {}
for a in anchors:
if signer_field and a.get("field") != signer_field:
continue
by_page.setdefault(int(a.get("page", 0)), []).append(a)
for i, page in enumerate(reader.pages):
page_anchors = by_page.get(i)
if page_anchors:
mb = page.mediabox
pw = float(mb.width)
ph = float(mb.height)
buf = io.BytesIO()
c = rl_canvas.Canvas(buf, pagesize=(pw, ph))
c.setStrokeColorRGB(0.06, 0.14, 0.25)
c.setLineWidth(1.3)
c.setLineCap(1)
c.setLineJoin(1)
for box in page_anchors:
# Scale anchor from authored page size to this page size.
sx = pw / (box.get("page_w") or pw)
sy = ph / (box.get("page_h") or ph)
scaled = {
"x": box["x"] * sx, "y": box["y"] * sy,
"w": box["w"] * sx, "h": box["h"] * sy,
}
for stroke in fit_strokes_to_box(vector, scaled):
if len(stroke) < 2:
continue
path = c.beginPath()
path.moveTo(*stroke[0])
for pt in stroke[1:]:
path.lineTo(*pt)
c.drawPath(path, stroke=1, fill=0)
c.save()
buf.seek(0)
overlay = PdfReader(buf)
page.merge_page(overlay.pages[0])
writer.add_page(page)
out = io.BytesIO()
writer.write(out)
return out.getvalue()
if __name__ == "__main__": # local demo: synth a signature, plan, preview, gcode
import json
# Synthetic cursive-ish signature (a few strokes), normalized 0..1.
def wave(n, x0, x1, y0, amp, ph):
return [{"x": x0 + (x1 - x0) * k / (n - 1),
"y": y0 + amp * math.sin(2 * math.pi * (k / (n - 1) * 2) + ph),
"t": k * 8} for k in range(n)]
vector = {"v": 1, "w": 600, "h": 160, "strokes": [
wave(40, 0.08, 0.45, 0.55, 0.18, 0.0),
wave(40, 0.50, 0.92, 0.55, 0.15, 1.2),
]}
box = {"field": "signer", "page": 4, "x": 64.0, "y": 471.0, "w": 402.0, "h": 19.0,
"page_w": 612.0, "page_h": 792.0}
cfg = PlotterConfig()
planned = plan_signature(vector, box, cfg)
print(f"planned strokes: {len(planned)}; points: {sum(len(s.points_mm) for s in planned)}")
with open("/tmp/ink_preview.svg", "w") as f:
f.write(render_preview_svg(planned, cfg))
gcode = emit_gcode(planned, cfg)
with open("/tmp/ink_signature.gcode", "w") as f:
f.write(gcode)
print("wrote /tmp/ink_preview.svg and /tmp/ink_signature.gcode")
print("first 12 gcode lines:")
print("\n".join(gcode.splitlines()[:12]))