motion_queuing: Add new module to help with motion queues and flushing

Create a new module to assist with host management of motion queues.
Register all MCU_stepper objects with this module and use the module
for step generation.

All steppers will now automatically generate steps whenever
toolhead._advance_flush_time() is invoked.  It is no longer necessary
for callers to individually call stepper.generate_steps().

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/force_move.py

@@ -85,14 +85,13 @@ class ForceMove:
         self.trapq_append(self.trapq, print_time, accel_t, cruise_t, accel_t,
                           0., 0., 0., axis_r, 0., 0., 0., cruise_v, accel)
         print_time = print_time + accel_t + cruise_t + accel_t
-        stepper.generate_steps(print_time)
-        self.trapq_finalize_moves(self.trapq, print_time + 99999.9,
-                                  print_time + 99999.9)
-        stepper.set_trapq(prev_trapq)
-        stepper.set_stepper_kinematics(prev_sk)
         toolhead.note_mcu_movequeue_activity(print_time)
         toolhead.dwell(accel_t + cruise_t + accel_t)
         toolhead.flush_step_generation()
+        stepper.set_trapq(prev_trapq)
+        stepper.set_stepper_kinematics(prev_sk)
+        self.trapq_finalize_moves(self.trapq, print_time + 99999.9,
+                                  print_time + 99999.9)
     def _lookup_stepper(self, gcmd):
         name = gcmd.get('STEPPER')
         if name not in self.steppers:

klippy/extras/manual_stepper.py

@@ -76,7 +76,6 @@ class ManualStepper:
         self.sync_print_time()
         self.next_cmd_time = self._submit_move(self.next_cmd_time, movepos,
                                                speed, accel)
-        self.rail.generate_steps(self.next_cmd_time)
         self.trapq_finalize_moves(self.trapq, self.next_cmd_time + 99999.9,
                                   self.next_cmd_time + 99999.9)
         toolhead = self.printer.lookup_object('toolhead')
@@ -138,7 +137,6 @@ class ManualStepper:
                 raise gcmd.error("Must unregister axis first")
             # Unregister
             toolhead.remove_extra_axis(self)
-            toolhead.unregister_step_generator(self.rail.generate_steps)
             self.axis_gcode_id = None
             return
         if (len(gcode_axis) != 1 or not gcode_axis.isupper()
@@ -155,7 +153,6 @@ class ManualStepper:
         self.gaxis_limit_velocity = limit_velocity
         self.gaxis_limit_accel = limit_accel
         toolhead.add_extra_axis(self, self.get_position()[0])
-        toolhead.register_step_generator(self.rail.generate_steps)
     def process_move(self, print_time, move, ea_index):
         axis_r = move.axes_r[ea_index]
         start_pos = move.start_pos[ea_index]
@@ -208,7 +205,7 @@ class ManualStepper:
                                     speed, self.homing_accel)
         # Drip updates to motors
         toolhead = self.printer.lookup_object('toolhead')
-        toolhead.drip_update_time(maxtime, drip_completion, self.steppers)
+        toolhead.drip_update_time(maxtime, drip_completion)
         # Clear trapq of any remaining parts of movement
         reactor = self.printer.get_reactor()
         self.trapq_finalize_moves(self.trapq, reactor.NEVER, 0)

klippy/extras/motion_queuing.py

@@ -0,0 +1,19 @@
+# Helper code for low-level motion queuing and flushing
+#
+# Copyright (C) 2025  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+
+class PrinterMotionQueuing:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.steppers = []
+    def register_stepper(self, config, stepper):
+        self.steppers.append(stepper)
+    def flush_motion_queues(self, must_flush_time, max_step_gen_time):
+        for stepper in self.steppers:
+            stepper.generate_steps(max_step_gen_time)
+
+def load_config(config):
+    return PrinterMotionQueuing(config)