klipper/klippy/extras/gcode_arcs.py

130 lines
4.9 KiB
Python

# adds support fro ARC commands via G2/G3
#
# Copyright (C) 2019 Aleksej Vasiljkovic <achmed21@gmail.com>
#
# function planArc() originates from https://github.com/MarlinFirmware/Marlin
# Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import math
# Coordinates created by this are converted into G1 commands.
#
# note: only IJ version available
class ArcSupport:
def __init__(self, config):
self.printer = config.get_printer()
self.mm_per_arc_segment = config.getfloat('resolution', 1., above=0.0)
self.gcode_move = self.printer.load_object(config, 'gcode_move')
self.gcode = self.printer.lookup_object('gcode')
self.gcode.register_command("G2", self.cmd_G2)
self.gcode.register_command("G3", self.cmd_G2)
def cmd_G2(self, gcmd):
gcodestatus = self.gcode_move.get_status()
if not gcodestatus['absolute_coordinates']:
raise gcmd.error("G2/G3 does not support relative move mode")
currentPos = gcodestatus['gcode_position']
# Parse parameters
asX = gcmd.get_float("X", currentPos[0])
asY = gcmd.get_float("Y", currentPos[1])
asZ = gcmd.get_float("Z", currentPos[2])
if gcmd.get_float("R", None) is not None:
raise gcmd.error("G2/G3 does not support R moves")
asI = gcmd.get_float("I", 0.)
asJ = gcmd.get_float("J", 0.)
if not asI and not asJ:
raise gcmd.error("G2/G3 neither I nor J given")
asE = gcmd.get_float("E", None)
asF = gcmd.get_float("F", None)
clockwise = (gcmd.get_command() == 'G2')
# Build list of linear coordinates to move to
coords = self.planArc(currentPos, [asX, asY, asZ], [asI, asJ],
clockwise)
e_per_move = e_base = 0.
if asE is not None:
if gcodestatus['absolute_extrude']:
e_base = currentPos[3]
e_per_move = (asE - e_base) / len(coords)
# Convert coords into G1 commands
for coord in coords:
g1_params = {'X': coord[0], 'Y': coord[1], 'Z': coord[2]}
if e_per_move:
g1_params['E'] = e_base + e_per_move
if gcodestatus['absolute_extrude']:
e_base += e_per_move
if asF is not None:
g1_params['F'] = asF
g1_gcmd = self.gcode.create_gcode_command("G1", "G1", g1_params)
self.gcode_move.cmd_G1(g1_gcmd)
# function planArc() originates from marlin plan_arc()
# https://github.com/MarlinFirmware/Marlin
#
# The arc is approximated by generating many small linear segments.
# The length of each segment is configured in MM_PER_ARC_SEGMENT
# Arcs smaller then this value, will be a Line only
def planArc(self, currentPos, targetPos, offset, clockwise):
# todo: sometimes produces full circles
X_AXIS = 0
Y_AXIS = 1
Z_AXIS = 2
# Radius vector from center to current location
r_P = -offset[0]
r_Q = -offset[1]
# Determine angular travel
center_P = currentPos[X_AXIS] - r_P
center_Q = currentPos[Y_AXIS] - r_Q
rt_X = targetPos[X_AXIS] - center_P
rt_Y = targetPos[Y_AXIS] - center_Q
angular_travel = math.atan2(r_P * rt_Y - r_Q * rt_X,
r_P * rt_X + r_Q * rt_Y)
if angular_travel < 0.:
angular_travel += 2. * math.pi
if clockwise:
angular_travel -= 2. * math.pi
if (angular_travel == 0.
and currentPos[X_AXIS] == targetPos[X_AXIS]
and currentPos[Y_AXIS] == targetPos[Y_AXIS]):
# Make a circle if the angular rotation is 0 and the
# target is current position
angular_travel = 2. * math.pi
# Determine number of segments
linear_travel = targetPos[Z_AXIS] - currentPos[Z_AXIS]
radius = math.hypot(r_P, r_Q)
flat_mm = radius * angular_travel
if linear_travel:
mm_of_travel = math.hypot(flat_mm, linear_travel)
else:
mm_of_travel = math.fabs(flat_mm)
segments = max(1., math.floor(mm_of_travel / self.mm_per_arc_segment))
# Generate coordinates
theta_per_segment = angular_travel / segments
linear_per_segment = linear_travel / segments
coords = []
for i in range(1, int(segments)):
dist_Z = i * linear_per_segment
cos_Ti = math.cos(i * theta_per_segment)
sin_Ti = math.sin(i * theta_per_segment)
r_P = -offset[0] * cos_Ti + offset[1] * sin_Ti
r_Q = -offset[0] * sin_Ti - offset[1] * cos_Ti
c = [center_P + r_P, center_Q + r_Q, currentPos[Z_AXIS] + dist_Z]
coords.append(c)
coords.append(targetPos)
return coords
def load_config(config):
return ArcSupport(config)