marlin/Marlin/src/module/motion.cpp

/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

/**
 * motion.cpp
 */

#include "motion.h"
#include "endstops.h"
#include "stepper.h"
#include "planner.h"
#include "temperature.h"

#include "../gcode/gcode.h"

#include "../inc/MarlinConfig.h"

#if IS_SCARA
  #include "../libs/buzzer.h"
  #include "../lcd/marlinui.h"
#endif

#if HAS_BED_PROBE
  #include "probe.h"
#endif

#if HAS_LEVELING
  #include "../feature/bedlevel/bedlevel.h"
#endif

#if ENABLED(BLTOUCH)
  #include "../feature/bltouch.h"
#endif

#if HAS_DISPLAY
  #include "../lcd/marlinui.h"
#endif

#if HAS_FILAMENT_SENSOR
  #include "../feature/runout.h"
#endif

#if ENABLED(SENSORLESS_HOMING)
  #include "../feature/tmc_util.h"
#endif

#if ENABLED(FWRETRACT)
  #include "../feature/fwretract.h"
#endif

#if ENABLED(BABYSTEP_DISPLAY_TOTAL)
  #include "../feature/babystep.h"
#endif

#define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
#include "../core/debug_out.h"

// Relative Mode. Enable with G91, disable with G90.
bool relative_mode; // = false;

/**
 * Cartesian Current Position
 *   Used to track the native machine position as moves are queued.
 *   Used by 'line_to_current_position' to do a move after changing it.
 *   Used by 'sync_plan_position' to update 'planner.position'.
 */
xyze_pos_t current_position = { X_HOME_POS, Y_HOME_POS,
  #ifdef Z_IDLE_HEIGHT
    Z_IDLE_HEIGHT
  #else
    Z_HOME_POS
  #endif
};

/**
 * Cartesian Destination
 *   The destination for a move, filled in by G-code movement commands,
 *   and expected by functions like 'prepare_line_to_destination'.
 *   G-codes can set destination using 'get_destination_from_command'
 */
xyze_pos_t destination; // {0}

// G60/G61 Position Save and Return
#if SAVED_POSITIONS
  uint8_t saved_slots[(SAVED_POSITIONS + 7) >> 3];
  xyz_pos_t stored_position[SAVED_POSITIONS];
#endif

// The active extruder (tool). Set with T<extruder> command.
#if HAS_MULTI_EXTRUDER
  uint8_t active_extruder = 0; // = 0
#endif

#if ENABLED(LCD_SHOW_E_TOTAL)
  float e_move_accumulator; // = 0
#endif

// Extruder offsets
#if HAS_HOTEND_OFFSET
  xyz_pos_t hotend_offset[HOTENDS]; // Initialized by settings.load()
  void reset_hotend_offsets() {
    constexpr float tmp[XYZ][HOTENDS] = { HOTEND_OFFSET_X, HOTEND_OFFSET_Y, HOTEND_OFFSET_Z };
    static_assert(
      !tmp[X_AXIS][0] && !tmp[Y_AXIS][0] && !tmp[Z_AXIS][0],
      "Offsets for the first hotend must be 0.0."
    );
    // Transpose from [XYZ][HOTENDS] to [HOTENDS][XYZ]
    HOTEND_LOOP() LOOP_XYZ(a) hotend_offset[e][a] = tmp[a][e];
    #if ENABLED(DUAL_X_CARRIAGE)
      hotend_offset[1].x = _MAX(X2_HOME_POS, X2_MAX_POS);
    #endif
  }
#endif

// The feedrate for the current move, often used as the default if
// no other feedrate is specified. Overridden for special moves.
// Set by the last G0 through G5 command's "F" parameter.
// Functions that override this for custom moves *must always* restore it!
feedRate_t feedrate_mm_s = MMM_TO_MMS(1500);
int16_t feedrate_percentage = 100;

// Cartesian conversion result goes here:
xyz_pos_t cartes;

#if IS_KINEMATIC

  abc_pos_t delta;

  #if HAS_SCARA_OFFSET
    abc_pos_t scara_home_offset;
  #endif

  #if HAS_SOFTWARE_ENDSTOPS
    float delta_max_radius, delta_max_radius_2;
  #elif IS_SCARA
    constexpr float delta_max_radius = SCARA_PRINTABLE_RADIUS,
                    delta_max_radius_2 = sq(SCARA_PRINTABLE_RADIUS);
  #else // DELTA
    constexpr float delta_max_radius = DELTA_PRINTABLE_RADIUS,
                    delta_max_radius_2 = sq(DELTA_PRINTABLE_RADIUS);
  #endif

#endif

/**
 * The workspace can be offset by some commands, or
 * these offsets may be omitted to save on computation.
 */
#if HAS_POSITION_SHIFT
  // The distance that XYZ has been offset by G92. Reset by G28.
  xyz_pos_t position_shift{0};
#endif
#if HAS_HOME_OFFSET
  // This offset is added to the configured home position.
  // Set by M206, M428, or menu item. Saved to EEPROM.
  xyz_pos_t home_offset{0};
#endif
#if HAS_HOME_OFFSET && HAS_POSITION_SHIFT
  // The above two are combined to save on computes
  xyz_pos_t workspace_offset{0};
#endif

#if HAS_ABL_NOT_UBL
  feedRate_t xy_probe_feedrate_mm_s = MMM_TO_MMS(XY_PROBE_FEEDRATE);
#endif

/**
 * Output the current position to serial
 */

inline void report_more_positions() {
  stepper.report_positions();
  TERN_(IS_SCARA, scara_report_positions());
}

// Report the logical position for a given machine position
inline void report_logical_position(const xyze_pos_t &rpos) {
  const xyze_pos_t lpos = rpos.asLogical();
  SERIAL_ECHOPAIR_P(X_LBL, lpos.x, SP_Y_LBL, lpos.y, SP_Z_LBL, lpos.z, SP_E_LBL, lpos.e);
}

// Report the real current position according to the steppers.
// Forward kinematics and un-leveling are applied.
void report_real_position() {
  get_cartesian_from_steppers();
  xyze_pos_t npos = cartes;
  npos.e = planner.get_axis_position_mm(E_AXIS);

  #if HAS_POSITION_MODIFIERS
    planner.unapply_modifiers(npos, true);
  #endif

  report_logical_position(npos);
  report_more_positions();
}

// Report the logical current position according to the most recent G-code command
void report_current_position() {
  report_logical_position(current_position);
  report_more_positions();
}

/**
 * Report the logical current position according to the most recent G-code command.
 * The planner.position always corresponds to the last G-code too. This makes M114
 * suitable for debugging kinematics and leveling while avoiding planner sync that
 * definitively interrupts the printing flow.
 */
void report_current_position_projected() {
  report_logical_position(current_position);
  stepper.report_a_position(planner.position);
}

/**
 * Run out the planner buffer and re-sync the current
 * position from the last-updated stepper positions.
 */
void quickstop_stepper() {
  planner.quick_stop();
  planner.synchronize();
  set_current_from_steppers_for_axis(ALL_AXES);
  sync_plan_position();
}

/**
 * Set the planner/stepper positions directly from current_position with
 * no kinematic translation. Used for homing axes and cartesian/core syncing.
 */
void sync_plan_position() {
  if (DEBUGGING(LEVELING)) DEBUG_POS("sync_plan_position", current_position);
  planner.set_position_mm(current_position);
}

void sync_plan_position_e() { planner.set_e_position_mm(current_position.e); }

/**
 * Get the stepper positions in the cartes[] array.
 * Forward kinematics are applied for DELTA and SCARA.
 *
 * The result is in the current coordinate space with
 * leveling applied. The coordinates need to be run through
 * unapply_leveling to obtain the "ideal" coordinates
 * suitable for current_position, etc.
 */
void get_cartesian_from_steppers() {
  #if ENABLED(DELTA)
    forward_kinematics_DELTA(planner.get_axis_positions_mm());
  #else
    #if IS_SCARA
      forward_kinematics_SCARA(
        planner.get_axis_position_degrees(A_AXIS),
        planner.get_axis_position_degrees(B_AXIS)
      );
    #else
      cartes.set(planner.get_axis_position_mm(X_AXIS), planner.get_axis_position_mm(Y_AXIS));
    #endif
    cartes.z = planner.get_axis_position_mm(Z_AXIS);
  #endif
}

/**
 * Set the current_position for an axis based on
 * the stepper positions, removing any leveling that
 * may have been applied.
 *
 * To prevent small shifts in axis position always call
 * sync_plan_position after updating axes with this.
 *
 * To keep hosts in sync, always call report_current_position
 * after updating the current_position.
 */
void set_current_from_steppers_for_axis(const AxisEnum axis) {
  get_cartesian_from_steppers();
  xyze_pos_t pos = cartes;
  pos.e = planner.get_axis_position_mm(E_AXIS);

  #if HAS_POSITION_MODIFIERS
    planner.unapply_modifiers(pos, true);
  #endif

  if (axis == ALL_AXES)
    current_position = pos;
  else
    current_position[axis] = pos[axis];
}

/**
 * Move the planner to the current position from wherever it last moved
 * (or from wherever it has been told it is located).
 */
void line_to_current_position(const feedRate_t &fr_mm_s/*=feedrate_mm_s*/) {
  planner.buffer_line(current_position, fr_mm_s, active_extruder);
}

#if EXTRUDERS
  void unscaled_e_move(const float &length, const feedRate_t &fr_mm_s) {
    TERN_(HAS_FILAMENT_SENSOR, runout.reset());
    current_position.e += length / planner.e_factor[active_extruder];
    line_to_current_position(fr_mm_s);
    planner.synchronize();
  }
#endif

#if IS_KINEMATIC

  /**
   * Buffer a fast move without interpolation. Set current_position to destination
   */
  void prepare_fast_move_to_destination(const feedRate_t &scaled_fr_mm_s/*=MMS_SCALED(feedrate_mm_s)*/) {
    if (DEBUGGING(LEVELING)) DEBUG_POS("prepare_fast_move_to_destination", destination);

    #if UBL_SEGMENTED
      // UBL segmented line will do Z-only moves in single segment
      ubl.line_to_destination_segmented(scaled_fr_mm_s);
    #else
      if (current_position == destination) return;

      planner.buffer_line(destination, scaled_fr_mm_s, active_extruder);
    #endif

    current_position = destination;
  }

#endif // IS_KINEMATIC

/**
 * Do a fast or normal move to 'destination' with an optional FR.
 *  - Move at normal speed regardless of feedrate percentage.
 *  - Extrude the specified length regardless of flow percentage.
 */
void _internal_move_to_destination(const feedRate_t &fr_mm_s/*=0.0f*/
  #if IS_KINEMATIC
    , const bool is_fast/*=false*/
  #endif
) {
  const feedRate_t old_feedrate = feedrate_mm_s;
  if (fr_mm_s) feedrate_mm_s = fr_mm_s;

  const uint16_t old_pct = feedrate_percentage;
  feedrate_percentage = 100;

  #if EXTRUDERS
    const float old_fac = planner.e_factor[active_extruder];
    planner.e_factor[active_extruder] = 1.0f;
  #endif

  #if IS_KINEMATIC
    if (is_fast)
      prepare_fast_move_to_destination();
    else
  #endif
      prepare_line_to_destination();

  feedrate_mm_s = old_feedrate;
  feedrate_percentage = old_pct;
  #if EXTRUDERS
    planner.e_factor[active_extruder] = old_fac;
  #endif
}

/**
 * Plan a move to (X, Y, Z) and set the current_position
 */
void do_blocking_move_to(const float rx, const float ry, const float rz, const feedRate_t &fr_mm_s/*=0.0*/) {
  DEBUG_SECTION(log_move, "do_blocking_move_to", DEBUGGING(LEVELING));
  if (DEBUGGING(LEVELING)) DEBUG_XYZ("> ", rx, ry, rz);

  const feedRate_t z_feedrate = fr_mm_s ?: homing_feedrate(Z_AXIS),
                  xy_feedrate = fr_mm_s ?: feedRate_t(XY_PROBE_FEEDRATE_MM_S);

  #if ENABLED(DELTA)

    if (!position_is_reachable(rx, ry)) return;

    REMEMBER(fr, feedrate_mm_s, xy_feedrate);

    destination = current_position;          // sync destination at the start

    if (DEBUGGING(LEVELING)) DEBUG_POS("destination = current_position", destination);

    // when in the danger zone
    if (current_position.z > delta_clip_start_height) {
      if (rz > delta_clip_start_height) {   // staying in the danger zone
        destination.set(rx, ry, rz);        // move directly (uninterpolated)
        prepare_internal_fast_move_to_destination();          // set current_position from destination
        if (DEBUGGING(LEVELING)) DEBUG_POS("danger zone move", current_position);
        return;
      }
      destination.z = delta_clip_start_height;
      prepare_internal_fast_move_to_destination();            // set current_position from destination
      if (DEBUGGING(LEVELING)) DEBUG_POS("zone border move", current_position);
    }

    if (rz > current_position.z) {                            // raising?
      destination.z = rz;
      prepare_internal_fast_move_to_destination(z_feedrate);  // set current_position from destination
      if (DEBUGGING(LEVELING)) DEBUG_POS("z raise move", current_position);
    }

    destination.set(rx, ry);
    prepare_internal_move_to_destination();                   // set current_position from destination
    if (DEBUGGING(LEVELING)) DEBUG_POS("xy move", current_position);

    if (rz < current_position.z) {                            // lowering?
      destination.z = rz;
      prepare_internal_fast_move_to_destination(z_feedrate);  // set current_position from destination
      if (DEBUGGING(LEVELING)) DEBUG_POS("z lower move", current_position);
    }

  #elif IS_SCARA

    if (!position_is_reachable(rx, ry)) return;

    destination = current_position;

    // If Z needs to raise, do it before moving XY
    if (destination.z < rz) {
      destination.z = rz;
      prepare_internal_fast_move_to_destination(z_feedrate);
    }

    destination.set(rx, ry);
    prepare_internal_fast_move_to_destination(xy_feedrate);

    // If Z needs to lower, do it after moving XY
    if (destination.z > rz) {
      destination.z = rz;
      prepare_internal_fast_move_to_destination(z_feedrate);
    }

  #else

    // If Z needs to raise, do it before moving XY
    if (current_position.z < rz) {
      current_position.z = rz;
      line_to_current_position(z_feedrate);
    }

    current_position.set(rx, ry);
    line_to_current_position(xy_feedrate);

    // If Z needs to lower, do it after moving XY
    if (current_position.z > rz) {
      current_position.z = rz;
      line_to_current_position(z_feedrate);
    }

  #endif

  planner.synchronize();
}

void do_blocking_move_to(const xy_pos_t &raw, const feedRate_t &fr_mm_s/*=0.0f*/) {
  do_blocking_move_to(raw.x, raw.y, current_position.z, fr_mm_s);
}
void do_blocking_move_to(const xyz_pos_t &raw, const feedRate_t &fr_mm_s/*=0.0f*/) {
  do_blocking_move_to(raw.x, raw.y, raw.z, fr_mm_s);
}
void do_blocking_move_to(const xyze_pos_t &raw, const feedRate_t &fr_mm_s/*=0.0f*/) {
  do_blocking_move_to(raw.x, raw.y, raw.z, fr_mm_s);
}

void do_blocking_move_to_x(const float &rx, const feedRate_t &fr_mm_s/*=0.0*/) {
  do_blocking_move_to(rx, current_position.y, current_position.z, fr_mm_s);
}
void do_blocking_move_to_y(const float &ry, const feedRate_t &fr_mm_s/*=0.0*/) {
  do_blocking_move_to(current_position.x, ry, current_position.z, fr_mm_s);
}
void do_blocking_move_to_z(const float &rz, const feedRate_t &fr_mm_s/*=0.0*/) {
  do_blocking_move_to_xy_z(current_position, rz, fr_mm_s);
}

void do_blocking_move_to_xy(const float &rx, const float &ry, const feedRate_t &fr_mm_s/*=0.0*/) {
  do_blocking_move_to(rx, ry, current_position.z, fr_mm_s);
}
void do_blocking_move_to_xy(const xy_pos_t &raw, const feedRate_t &fr_mm_s/*=0.0f*/) {
  do_blocking_move_to_xy(raw.x, raw.y, fr_mm_s);
}

void do_blocking_move_to_xy_z(const xy_pos_t &raw, const float &z, const feedRate_t &fr_mm_s/*=0.0f*/) {
  do_blocking_move_to(raw.x, raw.y, z, fr_mm_s);
}

void do_z_clearance(const float &zclear, const bool lower_allowed/*=false*/) {
  float zdest = zclear;
  if (!lower_allowed) NOLESS(zdest, current_position.z);
  do_blocking_move_to_z(_MIN(zdest, Z_MAX_POS), TERN(HAS_BED_PROBE, z_probe_fast_mm_s, homing_feedrate(Z_AXIS)));
}

//
// Prepare to do endstop or probe moves with custom feedrates.
//  - Save / restore current feedrate and multiplier
//
static float saved_feedrate_mm_s;
static int16_t saved_feedrate_percentage;
void remember_feedrate_and_scaling() {
  saved_feedrate_mm_s = feedrate_mm_s;
  saved_feedrate_percentage = feedrate_percentage;
}
void remember_feedrate_scaling_off() {
  remember_feedrate_and_scaling();
  feedrate_percentage = 100;
}
void restore_feedrate_and_scaling() {
  feedrate_mm_s = saved_feedrate_mm_s;
  feedrate_percentage = saved_feedrate_percentage;
}

#if HAS_SOFTWARE_ENDSTOPS

  // Software Endstops are based on the configured limits.
  soft_endstops_t soft_endstop = {
    true, false,
    { X_MIN_POS, Y_MIN_POS, Z_MIN_POS },
    { X_MAX_POS, Y_MAX_POS, Z_MAX_POS }
  };

  /**
   * Software endstops can be used to monitor the open end of
   * an axis that has a hardware endstop on the other end. Or
   * they can prevent axes from moving past endstops and grinding.
   *
   * To keep doing their job as the coordinate system changes,
   * the software endstop positions must be refreshed to remain
   * at the same positions relative to the machine.
   */
  void update_software_endstops(const AxisEnum axis
    #if HAS_HOTEND_OFFSET
      , const uint8_t old_tool_index/*=0*/
      , const uint8_t new_tool_index/*=0*/
    #endif
  ) {

    #if ENABLED(DUAL_X_CARRIAGE)

      if (axis == X_AXIS) {

        // In Dual X mode hotend_offset[X] is T1's home position
        const float dual_max_x = _MAX(hotend_offset[1].x, X2_MAX_POS);

        if (new_tool_index != 0) {
          // T1 can move from X2_MIN_POS to X2_MAX_POS or X2 home position (whichever is larger)
          soft_endstop.min.x = X2_MIN_POS;
          soft_endstop.max.x = dual_max_x;
        }
        else if (idex_is_duplicating()) {
          // In Duplication Mode, T0 can move as far left as X1_MIN_POS
          // but not so far to the right that T1 would move past the end
          soft_endstop.min.x = X1_MIN_POS;
          soft_endstop.max.x = _MIN(X1_MAX_POS, dual_max_x - duplicate_extruder_x_offset);
        }
        else {
          // In other modes, T0 can move from X1_MIN_POS to X1_MAX_POS
          soft_endstop.min.x = X1_MIN_POS;
          soft_endstop.max.x = X1_MAX_POS;
        }

      }

    #elif ENABLED(DELTA)

      soft_endstop.min[axis] = base_min_pos(axis);
      soft_endstop.max[axis] = (axis == Z_AXIS) ? delta_height - TERN0(HAS_BED_PROBE, probe.offset.z) : base_max_pos(axis);

      switch (axis) {
        case X_AXIS:
        case Y_AXIS:
          // Get a minimum radius for clamping
          delta_max_radius = _MIN(ABS(_MAX(soft_endstop.min.x, soft_endstop.min.y)), soft_endstop.max.x, soft_endstop.max.y);
          delta_max_radius_2 = sq(delta_max_radius);
          break;
        case Z_AXIS:
          delta_clip_start_height = soft_endstop.max[axis] - delta_safe_distance_from_top();
        default: break;
      }

    #elif HAS_HOTEND_OFFSET

      // Software endstops are relative to the tool 0 workspace, so
      // the movement limits must be shifted by the tool offset to
      // retain the same physical limit when other tools are selected.

      if (new_tool_index == old_tool_index || axis == Z_AXIS) { // The Z axis is "special" and shouldn't be modified
        const float offs = (axis == Z_AXIS) ? 0 : hotend_offset[active_extruder][axis];
        soft_endstop.min[axis] = base_min_pos(axis) + offs;
        soft_endstop.max[axis] = base_max_pos(axis) + offs;
      }
      else {
        const float diff = hotend_offset[new_tool_index][axis] - hotend_offset[old_tool_index][axis];
        soft_endstop.min[axis] += diff;
        soft_endstop.max[axis] += diff;
      }

    #else

      soft_endstop.min[axis] = base_min_pos(axis);
      soft_endstop.max[axis] = base_max_pos(axis);

    #endif

    if (DEBUGGING(LEVELING))
      SERIAL_ECHOLNPAIR("Axis ", XYZ_CHAR(axis), " min:", soft_endstop.min[axis], " max:", soft_endstop.max[axis]);
  }

  /**
   * Constrain the given coordinates to the software endstops.
   *
   * For DELTA/SCARA the XY constraint is based on the smallest
   * radius within the set software endstops.
   */
  void apply_motion_limits(xyz_pos_t &target) {

    if (!soft_endstop._enabled) return;

    #if IS_KINEMATIC

      if (TERN0(DELTA, !all_axes_homed())) return;

      #if BOTH(HAS_HOTEND_OFFSET, DELTA)
        // The effector center position will be the target minus the hotend offset.
        const xy_pos_t offs = hotend_offset[active_extruder];
      #else
        // SCARA needs to consider the angle of the arm through the entire move, so for now use no tool offset.
        constexpr xy_pos_t offs{0};
      #endif

      if (TERN1(IS_SCARA, axis_was_homed(X_AXIS) && axis_was_homed(Y_AXIS))) {
        const float dist_2 = HYPOT2(target.x - offs.x, target.y - offs.y);
        if (dist_2 > delta_max_radius_2)
          target *= float(delta_max_radius / SQRT(dist_2)); // 200 / 300 = 0.66
      }

    #else

      if (axis_was_homed(X_AXIS)) {
        #if !HAS_SOFTWARE_ENDSTOPS || ENABLED(MIN_SOFTWARE_ENDSTOP_X)
          NOLESS(target.x, soft_endstop.min.x);
        #endif
        #if !HAS_SOFTWARE_ENDSTOPS || ENABLED(MAX_SOFTWARE_ENDSTOP_X)
          NOMORE(target.x, soft_endstop.max.x);
        #endif
      }

      if (axis_was_homed(Y_AXIS)) {
        #if !HAS_SOFTWARE_ENDSTOPS || ENABLED(MIN_SOFTWARE_ENDSTOP_Y)
          NOLESS(target.y, soft_endstop.min.y);
        #endif
        #if !HAS_SOFTWARE_ENDSTOPS || ENABLED(MAX_SOFTWARE_ENDSTOP_Y)
          NOMORE(target.y, soft_endstop.max.y);
        #endif
      }

    #endif

    if (axis_was_homed(Z_AXIS)) {
      #if !HAS_SOFTWARE_ENDSTOPS || ENABLED(MIN_SOFTWARE_ENDSTOP_Z)
        NOLESS(target.z, soft_endstop.min.z);
      #endif
      #if !HAS_SOFTWARE_ENDSTOPS || ENABLED(MAX_SOFTWARE_ENDSTOP_Z)
        NOMORE(target.z, soft_endstop.max.z);
      #endif
    }
  }

#else // !HAS_SOFTWARE_ENDSTOPS

  soft_endstops_t soft_endstop;

#endif // !HAS_SOFTWARE_ENDSTOPS

#if !UBL_SEGMENTED

FORCE_INLINE void segment_idle(millis_t &next_idle_ms) {
  const millis_t ms = millis();
  if (ELAPSED(ms, next_idle_ms)) {
    next_idle_ms = ms + 200UL;
    return idle();
  }
  thermalManager.manage_heater();  // Returns immediately on most calls
}

#if IS_KINEMATIC

  #if IS_SCARA
    /**
     * Before raising this value, use M665 S[seg_per_sec] to decrease
     * the number of segments-per-second. Default is 200. Some deltas
     * do better with 160 or lower. It would be good to know how many
     * segments-per-second are actually possible for SCARA on AVR.
     *
     * Longer segments result in less kinematic overhead
     * but may produce jagged lines. Try 0.5mm, 1.0mm, and 2.0mm
     * and compare the difference.
     */
    #define SCARA_MIN_SEGMENT_LENGTH 0.5f
  #endif

  /**
   * Prepare a linear move in a DELTA or SCARA setup.
   *
   * Called from prepare_line_to_destination as the
   * default Delta/SCARA segmenter.
   *
   * This calls planner.buffer_line several times, adding
   * small incremental moves for DELTA or SCARA.
   *
   * For Unified Bed Leveling (Delta or Segmented Cartesian)
   * the ubl.line_to_destination_segmented method replaces this.
   *
   * For Auto Bed Leveling (Bilinear) with SEGMENT_LEVELED_MOVES
   * this is replaced by segmented_line_to_destination below.
   */
  inline bool line_to_destination_kinematic() {

    // Get the top feedrate of the move in the XY plane
    const float scaled_fr_mm_s = MMS_SCALED(feedrate_mm_s);

    const xyze_float_t diff = destination - current_position;

    // If the move is only in Z/E don't split up the move
    if (!diff.x && !diff.y) {
      planner.buffer_line(destination, scaled_fr_mm_s, active_extruder);
      return false; // caller will update current_position
    }

    // Fail if attempting move outside printable radius
    if (!position_is_reachable(destination)) return true;

    // Get the linear distance in XYZ
    float cartesian_mm = diff.magnitude();

    // If the move is very short, check the E move distance
    if (UNEAR_ZERO(cartesian_mm)) cartesian_mm = ABS(diff.e);

    // No E move either? Game over.
    if (UNEAR_ZERO(cartesian_mm)) return true;

    // Minimum number of seconds to move the given distance
    const float seconds = cartesian_mm / scaled_fr_mm_s;

    // The number of segments-per-second times the duration
    // gives the number of segments
    uint16_t segments = delta_segments_per_second * seconds;

    // For SCARA enforce a minimum segment size
    #if IS_SCARA
      NOMORE(segments, cartesian_mm * RECIPROCAL(SCARA_MIN_SEGMENT_LENGTH));
    #endif

    // At least one segment is required
    NOLESS(segments, 1U);

    // The approximate length of each segment
    const float inv_segments = 1.0f / float(segments),
                cartesian_segment_mm = cartesian_mm * inv_segments;
    const xyze_float_t segment_distance = diff * inv_segments;

    #if ENABLED(SCARA_FEEDRATE_SCALING)
      const float inv_duration = scaled_fr_mm_s / cartesian_segment_mm;
    #endif

    /*
    SERIAL_ECHOPAIR("mm=", cartesian_mm);
    SERIAL_ECHOPAIR(" seconds=", seconds);
    SERIAL_ECHOPAIR(" segments=", segments);
    SERIAL_ECHOPAIR(" segment_mm=", cartesian_segment_mm);
    SERIAL_EOL();
    //*/

    // Get the current position as starting point
    xyze_pos_t raw = current_position;

    // Calculate and execute the segments
    millis_t next_idle_ms = millis() + 200UL;
    while (--segments) {
      segment_idle(next_idle_ms);
      raw += segment_distance;
      if (!planner.buffer_line(raw, scaled_fr_mm_s, active_extruder, cartesian_segment_mm
        #if ENABLED(SCARA_FEEDRATE_SCALING)
          , inv_duration
        #endif
      )) break;
    }

    // Ensure last segment arrives at target location.
    planner.buffer_line(destination, scaled_fr_mm_s, active_extruder, cartesian_segment_mm
      #if ENABLED(SCARA_FEEDRATE_SCALING)
        , inv_duration
      #endif
    );

    return false; // caller will update current_position
  }

#else // !IS_KINEMATIC

  #if ENABLED(SEGMENT_LEVELED_MOVES)

    /**
     * Prepare a segmented move on a CARTESIAN setup.
     *
     * This calls planner.buffer_line several times, adding
     * small incremental moves. This allows the planner to
     * apply more detailed bed leveling to the full move.
     */
    inline void segmented_line_to_destination(const feedRate_t &fr_mm_s, const float segment_size=LEVELED_SEGMENT_LENGTH) {

      const xyze_float_t diff = destination - current_position;

      // If the move is only in Z/E don't split up the move
      if (!diff.x && !diff.y) {
        planner.buffer_line(destination, fr_mm_s, active_extruder);
        return;
      }

      // Get the linear distance in XYZ
      // If the move is very short, check the E move distance
      // No E move either? Game over.
      float cartesian_mm = diff.magnitude();
      if (UNEAR_ZERO(cartesian_mm)) cartesian_mm = ABS(diff.e);
      if (UNEAR_ZERO(cartesian_mm)) return;

      // The length divided by the segment size
      // At least one segment is required
      uint16_t segments = cartesian_mm / segment_size;
      NOLESS(segments, 1U);

      // The approximate length of each segment
      const float inv_segments = 1.0f / float(segments),
                  cartesian_segment_mm = cartesian_mm * inv_segments;
      const xyze_float_t segment_distance = diff * inv_segments;

      #if ENABLED(SCARA_FEEDRATE_SCALING)
        const float inv_duration = scaled_fr_mm_s / cartesian_segment_mm;
      #endif

      // SERIAL_ECHOPAIR("mm=", cartesian_mm);
      // SERIAL_ECHOLNPAIR(" segments=", segments);
      // SERIAL_ECHOLNPAIR(" segment_mm=", cartesian_segment_mm);

      // Get the raw current position as starting point
      xyze_pos_t raw = current_position;

      // Calculate and execute the segments
      millis_t next_idle_ms = millis() + 200UL;
      while (--segments) {
        segment_idle(next_idle_ms);
        raw += segment_distance;
        if (!planner.buffer_line(raw, fr_mm_s, active_extruder, cartesian_segment_mm
          #if ENABLED(SCARA_FEEDRATE_SCALING)
            , inv_duration
          #endif
        )) break;
      }

      // Since segment_distance is only approximate,
      // the final move must be to the exact destination.
      planner.buffer_line(destination, fr_mm_s, active_extruder, cartesian_segment_mm
        #if ENABLED(SCARA_FEEDRATE_SCALING)
          , inv_duration
        #endif
      );
    }

  #endif // SEGMENT_LEVELED_MOVES

  /**
   * Prepare a linear move in a Cartesian setup.
   *
   * When a mesh-based leveling system is active, moves are segmented
   * according to the configuration of the leveling system.
   *
   * Return true if 'current_position' was set to 'destination'
   */
  inline bool line_to_destination_cartesian() {
    const float scaled_fr_mm_s = MMS_SCALED(feedrate_mm_s);
    #if HAS_MESH
      if (planner.leveling_active && planner.leveling_active_at_z(destination.z)) {
        #if ENABLED(AUTO_BED_LEVELING_UBL)
          ubl.line_to_destination_cartesian(scaled_fr_mm_s, active_extruder); // UBL's motion routine needs to know about
          return true;                                                        // all moves, including Z-only moves.
        #elif ENABLED(SEGMENT_LEVELED_MOVES)
          segmented_line_to_destination(scaled_fr_mm_s);
          return false; // caller will update current_position
        #else
          /**
           * For MBL and ABL-BILINEAR only segment moves when X or Y are involved.
           * Otherwise fall through to do a direct single move.
           */
          if (xy_pos_t(current_position) != xy_pos_t(destination)) {
            #if ENABLED(MESH_BED_LEVELING)
              mbl.line_to_destination(scaled_fr_mm_s);
            #elif ENABLED(AUTO_BED_LEVELING_BILINEAR)
              bilinear_line_to_destination(scaled_fr_mm_s);
            #endif
            return true;
          }
        #endif
      }
    #endif // HAS_MESH

    planner.buffer_line(destination, scaled_fr_mm_s, active_extruder);
    return false; // caller will update current_position
  }

#endif // !IS_KINEMATIC
#endif // !UBL_SEGMENTED

#if HAS_DUPLICATION_MODE
  bool extruder_duplication_enabled;
  #if ENABLED(MULTI_NOZZLE_DUPLICATION)
    uint8_t duplication_e_mask; // = 0
  #endif
#endif

#if ENABLED(DUAL_X_CARRIAGE)

  DualXMode dual_x_carriage_mode         = DEFAULT_DUAL_X_CARRIAGE_MODE;
  float inactive_extruder_x              = X2_MAX_POS,                    // Used in mode 0 & 1
        duplicate_extruder_x_offset      = DEFAULT_DUPLICATION_X_OFFSET;  // Used in mode 2
  xyz_pos_t raised_parked_position;                                       // Used in mode 1
  bool active_extruder_parked            = false;                         // Used in mode 1 & 2
  millis_t delayed_move_time             = 0;                             // Used in mode 1
  int16_t duplicate_extruder_temp_offset = 0;                             // Used in mode 2
  bool idex_mirrored_mode                = false;                         // Used in mode 3

  float x_home_pos(const uint8_t extruder) {
    if (extruder == 0)
      return base_home_pos(X_AXIS);
    else
      /**
       * In dual carriage mode the extruder offset provides an override of the
       * second X-carriage position when homed - otherwise X2_HOME_POS is used.
       * This allows soft recalibration of the second extruder home position
       * without firmware reflash (through the M218 command).
       */
      return hotend_offset[1].x > 0 ? hotend_offset[1].x : X2_HOME_POS;
  }

  void idex_set_mirrored_mode(const bool mirr) {
    idex_mirrored_mode = mirr;
    stepper.set_directions();
  }

  void set_duplication_enabled(const bool dupe, const int8_t tool_index/*=-1*/) {
    extruder_duplication_enabled = dupe;
    if (tool_index >= 0) active_extruder = tool_index;
    stepper.set_directions();
  }

  void idex_set_parked(const bool park/*=true*/) {
    delayed_move_time = 0;
    active_extruder_parked = park;
    if (park) raised_parked_position = current_position;  // Remember current raised toolhead position for use by unpark
  }

  /**
   * Prepare a linear move in a dual X axis setup
   *
   * Return true if current_position[] was set to destination[]
   */
  inline bool dual_x_carriage_unpark() {
    if (active_extruder_parked) {
      switch (dual_x_carriage_mode) {

        case DXC_FULL_CONTROL_MODE: break;

        case DXC_AUTO_PARK_MODE: {
          if (current_position.e == destination.e) {
            // This is a travel move (with no extrusion)
            // Skip it, but keep track of the current position
            // (so it can be used as the start of the next non-travel move)
            if (delayed_move_time != 0xFFFFFFFFUL) {
              current_position = destination;
              NOLESS(raised_parked_position.z, destination.z);
              delayed_move_time = millis() + 1000UL;
              return true;
            }
          }
          //
          // Un-park the active extruder
          //
          const feedRate_t fr_zfast = planner.settings.max_feedrate_mm_s[Z_AXIS];
          #define CURPOS current_position
          #define RAISED raised_parked_position
          //  1. Move to the raised parked XYZ. Presumably the tool is already at XY.
          if (planner.buffer_line(RAISED.x, RAISED.y, RAISED.z, CURPOS.e, fr_zfast, active_extruder)) {
            //  2. Move to the current native XY and raised Z. Presumably this is a null move.
            if (planner.buffer_line(CURPOS.x, CURPOS.y, RAISED.z, CURPOS.e, PLANNER_XY_FEEDRATE(), active_extruder)) {
              //  3. Lower Z back down
              line_to_current_position(fr_zfast);
            }
          }
          stepper.set_directions();

          idex_set_parked(false);
          if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("idex_set_parked(false)");
        } break;

        case DXC_MIRRORED_MODE:
        case DXC_DUPLICATION_MODE:
          if (active_extruder == 0) {
            xyze_pos_t new_pos = current_position;
            if (dual_x_carriage_mode == DXC_DUPLICATION_MODE)
              new_pos.x += duplicate_extruder_x_offset;
            else
              new_pos.x = inactive_extruder_x;
            // Move duplicate extruder into correct duplication position.
            if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Set planner X", inactive_extruder_x, " ... Line to X", new_pos.x);
            planner.set_position_mm(inactive_extruder_x, current_position.y, current_position.z, current_position.e);
            if (!planner.buffer_line(new_pos, planner.settings.max_feedrate_mm_s[X_AXIS], 1)) break;

            planner.synchronize();
            sync_plan_position();

            set_duplication_enabled(true);
            idex_set_parked(false);
            if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("set_duplication_enabled(true)\nidex_set_parked(false)");
          }
          else if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("Active extruder not 0");
          break;
      }
    }
    return false;
  }

#endif // DUAL_X_CARRIAGE

/**
 * Prepare a single move and get ready for the next one
 *
 * This may result in several calls to planner.buffer_line to
 * do smaller moves for DELTA, SCARA, mesh moves, etc.
 *
 * Make sure current_position.e and destination.e are good
 * before calling or cold/lengthy extrusion may get missed.
 *
 * Before exit, current_position is set to destination.
 */
void prepare_line_to_destination() {
  apply_motion_limits(destination);

  #if EITHER(PREVENT_COLD_EXTRUSION, PREVENT_LENGTHY_EXTRUDE)

    if (!DEBUGGING(DRYRUN) && destination.e != current_position.e) {
      bool ignore_e = false;

      #if ENABLED(PREVENT_COLD_EXTRUSION)
        ignore_e = thermalManager.tooColdToExtrude(active_extruder);
        if (ignore_e) SERIAL_ECHO_MSG(STR_ERR_COLD_EXTRUDE_STOP);
      #endif

      #if ENABLED(PREVENT_LENGTHY_EXTRUDE)
        const float e_delta = ABS(destination.e - current_position.e) * planner.e_factor[active_extruder];
        if (e_delta > (EXTRUDE_MAXLENGTH)) {
          #if ENABLED(MIXING_EXTRUDER)
            float collector[MIXING_STEPPERS];
            mixer.refresh_collector(1.0, mixer.get_current_vtool(), collector);
            MIXER_STEPPER_LOOP(e) {
              if (e_delta * collector[e] > (EXTRUDE_MAXLENGTH)) {
                ignore_e = true;
                SERIAL_ECHO_MSG(STR_ERR_LONG_EXTRUDE_STOP);
                break;
              }
            }
          #else
            ignore_e = true;
            SERIAL_ECHO_MSG(STR_ERR_LONG_EXTRUDE_STOP);
          #endif
        }
      #endif

      if (ignore_e) {
        current_position.e = destination.e;       // Behave as if the E move really took place
        planner.set_e_position_mm(destination.e); // Prevent the planner from complaining too
      }
    }

  #endif // PREVENT_COLD_EXTRUSION || PREVENT_LENGTHY_EXTRUDE

  if (TERN0(DUAL_X_CARRIAGE, dual_x_carriage_unpark())) return;

  if (
    #if UBL_SEGMENTED
      #if IS_KINEMATIC // UBL using Kinematic / Cartesian cases as a workaround for now.
        ubl.line_to_destination_segmented(MMS_SCALED(feedrate_mm_s))
      #else
        line_to_destination_cartesian()
      #endif
    #elif IS_KINEMATIC
      line_to_destination_kinematic()
    #else
      line_to_destination_cartesian()
    #endif
  ) return;

  current_position = destination;
}

#if HAS_ENDSTOPS

  uint8_t axis_homed, axis_trusted; // = 0

  uint8_t axes_should_home(uint8_t axis_bits/*=0x07*/) {
    #define SHOULD_HOME(A) TERN(HOME_AFTER_DEACTIVATE, axis_is_trusted, axis_was_homed)(A)
    // Clear test bits that are trusted
    if (TEST(axis_bits, X_AXIS) && SHOULD_HOME(X_AXIS)) CBI(axis_bits, X_AXIS);
    if (TEST(axis_bits, Y_AXIS) && SHOULD_HOME(Y_AXIS)) CBI(axis_bits, Y_AXIS);
    if (TEST(axis_bits, Z_AXIS) && SHOULD_HOME(Z_AXIS)) CBI(axis_bits, Z_AXIS);
    return axis_bits;
  }

  bool homing_needed_error(uint8_t axis_bits/*=0x07*/) {
    if ((axis_bits = axes_should_home(axis_bits))) {
      PGM_P home_first = GET_TEXT(MSG_HOME_FIRST);
      char msg[strlen_P(home_first)+1];
      sprintf_P(msg, home_first,
        TEST(axis_bits, X_AXIS) ? "X" : "",
        TEST(axis_bits, Y_AXIS) ? "Y" : "",
        TEST(axis_bits, Z_AXIS) ? "Z" : ""
      );
      SERIAL_ECHO_START();
      SERIAL_ECHOLN(msg);
      TERN_(HAS_DISPLAY, ui.set_status(msg));
      return true;
    }
    return false;
  }

  /**
   * Homing bump feedrate (mm/s)
   */
  feedRate_t get_homing_bump_feedrate(const AxisEnum axis) {
    #if HOMING_Z_WITH_PROBE
      if (axis == Z_AXIS) return MMM_TO_MMS(Z_PROBE_FEEDRATE_SLOW);
    #endif
    static const uint8_t homing_bump_divisor[] PROGMEM = HOMING_BUMP_DIVISOR;
    uint8_t hbd = pgm_read_byte(&homing_bump_divisor[axis]);
    if (hbd < 1) {
      hbd = 10;
      SERIAL_ECHO_MSG("Warning: Homing Bump Divisor < 1");
    }
    return homing_feedrate(axis) / float(hbd);
  }

  #if ENABLED(SENSORLESS_HOMING)
    /**
     * Set sensorless homing if the axis has it, accounting for Core Kinematics.
     */
    sensorless_t start_sensorless_homing_per_axis(const AxisEnum axis) {
      sensorless_t stealth_states { false };

      switch (axis) {
        default: break;
        #if X_SENSORLESS
          case X_AXIS:
            stealth_states.x = tmc_enable_stallguard(stepperX);
            #if AXIS_HAS_STALLGUARD(X2)
              stealth_states.x2 = tmc_enable_stallguard(stepperX2);
            #endif
            #if EITHER(CORE_IS_XY, MARKFORGED_XY) && Y_SENSORLESS
              stealth_states.y = tmc_enable_stallguard(stepperY);
            #elif CORE_IS_XZ && Z_SENSORLESS
              stealth_states.z = tmc_enable_stallguard(stepperZ);
            #endif
            break;
        #endif
        #if Y_SENSORLESS
          case Y_AXIS:
            stealth_states.y = tmc_enable_stallguard(stepperY);
            #if AXIS_HAS_STALLGUARD(Y2)
              stealth_states.y2 = tmc_enable_stallguard(stepperY2);
            #endif
            #if EITHER(CORE_IS_XY, MARKFORGED_XY) && X_SENSORLESS
              stealth_states.x = tmc_enable_stallguard(stepperX);
            #elif CORE_IS_YZ && Z_SENSORLESS
              stealth_states.z = tmc_enable_stallguard(stepperZ);
            #endif
            break;
        #endif
        #if Z_SENSORLESS
          case Z_AXIS:
            stealth_states.z = tmc_enable_stallguard(stepperZ);
            #if AXIS_HAS_STALLGUARD(Z2)
              stealth_states.z2 = tmc_enable_stallguard(stepperZ2);
            #endif
            #if AXIS_HAS_STALLGUARD(Z3)
              stealth_states.z3 = tmc_enable_stallguard(stepperZ3);
            #endif
            #if AXIS_HAS_STALLGUARD(Z4)
              stealth_states.z4 = tmc_enable_stallguard(stepperZ4);
            #endif
            #if CORE_IS_XZ && X_SENSORLESS
              stealth_states.x = tmc_enable_stallguard(stepperX);
            #elif CORE_IS_YZ && Y_SENSORLESS
              stealth_states.y = tmc_enable_stallguard(stepperY);
            #endif
            break;
        #endif
      }

      #if ENABLED(SPI_ENDSTOPS)
        switch (axis) {
          case X_AXIS: if (ENABLED(X_SPI_SENSORLESS)) endstops.tmc_spi_homing.x = true; break;
          case Y_AXIS: if (ENABLED(Y_SPI_SENSORLESS)) endstops.tmc_spi_homing.y = true; break;
          case Z_AXIS: if (ENABLED(Z_SPI_SENSORLESS)) endstops.tmc_spi_homing.z = true; break;
          default: break;
        }
      #endif

      TERN_(IMPROVE_HOMING_RELIABILITY, sg_guard_period = millis() + default_sg_guard_duration);

      return stealth_states;
    }

    void end_sensorless_homing_per_axis(const AxisEnum axis, sensorless_t enable_stealth) {
      switch (axis) {
        default: break;
        #if X_SENSORLESS
          case X_AXIS:
            tmc_disable_stallguard(stepperX, enable_stealth.x);
            #if AXIS_HAS_STALLGUARD(X2)
              tmc_disable_stallguard(stepperX2, enable_stealth.x2);
            #endif
            #if EITHER(CORE_IS_XY, MARKFORGED_XY) && Y_SENSORLESS
              tmc_disable_stallguard(stepperY, enable_stealth.y);
            #elif CORE_IS_XZ && Z_SENSORLESS
              tmc_disable_stallguard(stepperZ, enable_stealth.z);
            #endif
            break;
        #endif
        #if Y_SENSORLESS
          case Y_AXIS:
            tmc_disable_stallguard(stepperY, enable_stealth.y);
            #if AXIS_HAS_STALLGUARD(Y2)
              tmc_disable_stallguard(stepperY2, enable_stealth.y2);
            #endif
            #if EITHER(CORE_IS_XY, MARKFORGED_XY) && X_SENSORLESS
              tmc_disable_stallguard(stepperX, enable_stealth.x);
            #elif CORE_IS_YZ && Z_SENSORLESS
              tmc_disable_stallguard(stepperZ, enable_stealth.z);
            #endif
            break;
        #endif
        #if Z_SENSORLESS
          case Z_AXIS:
            tmc_disable_stallguard(stepperZ, enable_stealth.z);
            #if AXIS_HAS_STALLGUARD(Z2)
              tmc_disable_stallguard(stepperZ2, enable_stealth.z2);
            #endif
            #if AXIS_HAS_STALLGUARD(Z3)
              tmc_disable_stallguard(stepperZ3, enable_stealth.z3);
            #endif
            #if AXIS_HAS_STALLGUARD(Z4)
              tmc_disable_stallguard(stepperZ4, enable_stealth.z4);
            #endif
            #if CORE_IS_XZ && X_SENSORLESS
              tmc_disable_stallguard(stepperX, enable_stealth.x);
            #elif CORE_IS_YZ && Y_SENSORLESS
              tmc_disable_stallguard(stepperY, enable_stealth.y);
            #endif
            break;
        #endif
      }

      #if ENABLED(SPI_ENDSTOPS)
        switch (axis) {
          case X_AXIS: if (ENABLED(X_SPI_SENSORLESS)) endstops.tmc_spi_homing.x = false; break;
          case Y_AXIS: if (ENABLED(Y_SPI_SENSORLESS)) endstops.tmc_spi_homing.y = false; break;
          case Z_AXIS: if (ENABLED(Z_SPI_SENSORLESS)) endstops.tmc_spi_homing.z = false; break;
          default: break;
        }
      #endif
    }

  #endif // SENSORLESS_HOMING

  /**
   * Home an individual linear axis
   */
  void do_homing_move(const AxisEnum axis, const float distance, const feedRate_t fr_mm_s=0.0, const bool final_approach=true) {
    DEBUG_SECTION(log_move, "do_homing_move", DEBUGGING(LEVELING));

    const feedRate_t home_fr_mm_s = fr_mm_s ?: homing_feedrate(axis);

    if (DEBUGGING(LEVELING)) {
      DEBUG_ECHOPAIR("...(", AS_CHAR(axis_codes[axis]), ", ", distance, ", ");
      if (fr_mm_s)
        DEBUG_ECHO(fr_mm_s);
      else
        DEBUG_ECHOPAIR("[", home_fr_mm_s, "]");
      DEBUG_ECHOLNPGM(")");
    }

    // Only do some things when moving towards an endstop
    const int8_t axis_home_dir = TERN0(DUAL_X_CARRIAGE, axis == X_AXIS)
                  ? x_home_dir(active_extruder) : home_dir(axis);
    const bool is_home_dir = (axis_home_dir > 0) == (distance > 0);

    #if ENABLED(SENSORLESS_HOMING)
      sensorless_t stealth_states;
    #endif

    if (is_home_dir) {

      if (TERN0(HOMING_Z_WITH_PROBE, axis == Z_AXIS)) {
        #if BOTH(HAS_HEATED_BED, WAIT_FOR_BED_HEATER)
          // Wait for bed to heat back up between probing points
          thermalManager.wait_for_bed_heating();
        #endif

        #if BOTH(HAS_HOTEND, WAIT_FOR_HOTEND)
          // Wait for the hotend to heat back up between probing points
          thermalManager.wait_for_hotend_heating(active_extruder);
        #endif

        TERN_(HAS_QUIET_PROBING, if (final_approach) probe.set_probing_paused(true));
      }

      // Disable stealthChop if used. Enable diag1 pin on driver.
      TERN_(SENSORLESS_HOMING, stealth_states = start_sensorless_homing_per_axis(axis));
    }

    #if IS_SCARA
      // Tell the planner the axis is at 0
      current_position[axis] = 0;
      sync_plan_position();
      current_position[axis] = distance;
      line_to_current_position(home_fr_mm_s);
    #else
      // Get the ABC or XYZ positions in mm
      abce_pos_t target = planner.get_axis_positions_mm();

      target[axis] = 0;                         // Set the single homing axis to 0
      planner.set_machine_position_mm(target);  // Update the machine position

      #if HAS_DIST_MM_ARG
        const xyze_float_t cart_dist_mm{0};
      #endif

      // Set delta/cartesian axes directly
      target[axis] = distance;                  // The move will be towards the endstop
      planner.buffer_segment(target
        #if HAS_DIST_MM_ARG
          , cart_dist_mm
        #endif
        , home_fr_mm_s, active_extruder
      );
    #endif

    planner.synchronize();

    if (is_home_dir) {

      #if HOMING_Z_WITH_PROBE && HAS_QUIET_PROBING
        if (axis == Z_AXIS && final_approach) probe.set_probing_paused(false);
      #endif

      endstops.validate_homing_move();

      // Re-enable stealthChop if used. Disable diag1 pin on driver.
      TERN_(SENSORLESS_HOMING, end_sensorless_homing_per_axis(axis, stealth_states));
    }
  }

  /**
   * Set an axis to be unhomed. (Unless we are on a machine - e.g. a cheap Chinese CNC machine -
   * that has no endstops. Such machines should always be considered to be in a "known" and
   * "trusted" position).
   */
  void set_axis_never_homed(const AxisEnum axis) {
    if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR(">>> set_axis_never_homed(", axis_codes[axis], ")");

    set_axis_untrusted(axis);
    set_axis_unhomed(axis);

    if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("<<< set_axis_never_homed(", axis_codes[axis], ")");

    TERN_(I2C_POSITION_ENCODERS, I2CPEM.unhomed(axis));
  }

  #ifdef TMC_HOME_PHASE
    /**
     * Move the axis back to its home_phase if set and driver is capable (TMC)
     *
     * Improves homing repeatability by homing to stepper coil's nearest absolute
     * phase position. Trinamic drivers use a stepper phase table with 1024 values
     * spanning 4 full steps with 256 positions each (ergo, 1024 positions).
     */
    void backout_to_tmc_homing_phase(const AxisEnum axis) {
      const xyz_long_t home_phase = TMC_HOME_PHASE;

      // check if home phase is disabled for this axis.
      if (home_phase[axis] < 0) return;

      int16_t phasePerUStep,      // TMC µsteps(phase) per Marlin µsteps
              phaseCurrent,       // The TMC µsteps(phase) count of the current position
              effectorBackoutDir, // Direction in which the effector mm coordinates move away from endstop.
              stepperBackoutDir;  // Direction in which the TMC µstep count(phase) move away from endstop.

      #define PHASE_PER_MICROSTEP(N) (256 / _MAX(1, N##_MICROSTEPS))

      switch (axis) {
        #ifdef X_MICROSTEPS
          case X_AXIS:
            phasePerUStep = PHASE_PER_MICROSTEP(X);
            phaseCurrent = stepperX.get_microstep_counter();
            effectorBackoutDir = -X_HOME_DIR;
            stepperBackoutDir = INVERT_X_DIR ? effectorBackoutDir : -effectorBackoutDir;
            break;
        #endif
        #ifdef Y_MICROSTEPS
          case Y_AXIS:
            phasePerUStep = PHASE_PER_MICROSTEP(Y);
            phaseCurrent = stepperY.get_microstep_counter();
            effectorBackoutDir = -Y_HOME_DIR;
            stepperBackoutDir = INVERT_Y_DIR ? effectorBackoutDir : -effectorBackoutDir;
            break;
        #endif
        #ifdef Z_MICROSTEPS
          case Z_AXIS:
            phasePerUStep = PHASE_PER_MICROSTEP(Z);
            phaseCurrent = stepperZ.get_microstep_counter();
            effectorBackoutDir = -Z_HOME_DIR;
            stepperBackoutDir = INVERT_Z_DIR ? effectorBackoutDir : -effectorBackoutDir;
            break;
        #endif
        default: return;
      }

      // Phase distance to nearest home phase position when moving in the backout direction from endstop(may be negative).
      int16_t phaseDelta = (home_phase[axis] - phaseCurrent) * stepperBackoutDir;

      // Check if home distance within endstop assumed repeatability noise of .05mm and warn.
      if (ABS(phaseDelta) * planner.steps_to_mm[axis] / phasePerUStep < 0.05f)
        SERIAL_ECHOLNPAIR("Selected home phase ", home_phase[axis],
                         " too close to endstop trigger phase ", phaseCurrent,
                         ". Pick a different phase for ", axis_codes[axis]);

      // Skip to next if target position is behind current. So it only moves away from endstop.
      if (phaseDelta < 0) phaseDelta += 1024;

      // Convert TMC µsteps(phase) to whole Marlin µsteps to effector backout direction to mm
      const float mmDelta = int16_t(phaseDelta / phasePerUStep) * effectorBackoutDir * planner.steps_to_mm[axis];

      // Optional debug messages
      if (DEBUGGING(LEVELING)) {
        DEBUG_ECHOLNPAIR(
          "Endstop ", axis_codes[axis], " hit at Phase:", phaseCurrent,
          " Delta:", phaseDelta, " Distance:", mmDelta
        );
      }

      if (mmDelta != 0) {
        // Retrace by the amount computed in mmDelta.
        do_homing_move(axis, mmDelta, get_homing_bump_feedrate(axis));
      }
    }
  #endif

  /**
   * Home an individual "raw axis" to its endstop.
   * This applies to XYZ on Cartesian and Core robots, and
   * to the individual ABC steppers on DELTA and SCARA.
   *
   * At the end of the procedure the axis is marked as
   * homed and the current position of that axis is updated.
   * Kinematic robots should wait till all axes are homed
   * before updating the current position.
   */

  void homeaxis(const AxisEnum axis) {

    #if IS_SCARA
      // Only Z homing (with probe) is permitted
      if (axis != Z_AXIS) { BUZZ(100, 880); return; }
    #else
      #define _CAN_HOME(A) (axis == _AXIS(A) && ( \
           ENABLED(A##_SPI_SENSORLESS) \
        || (_AXIS(A) == Z_AXIS && ENABLED(HOMING_Z_WITH_PROBE)) \
        || (A##_MIN_PIN > -1 && A##_HOME_DIR < 0) \
        || (A##_MAX_PIN > -1 && A##_HOME_DIR > 0) \
      ))
      if (!_CAN_HOME(X) && !_CAN_HOME(Y) && !_CAN_HOME(Z)) return;
    #endif

    if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR(">>> homeaxis(", axis_codes[axis], ")");

    const int axis_home_dir = TERN0(DUAL_X_CARRIAGE, axis == X_AXIS)
                ? x_home_dir(active_extruder) : home_dir(axis);

    //
    // Homing Z with a probe? Raise Z (maybe) and deploy the Z probe.
    //
    if (TERN0(HOMING_Z_WITH_PROBE, axis == Z_AXIS && probe.deploy()))
      return;

    // Set flags for X, Y, Z motor locking
    #if HAS_EXTRA_ENDSTOPS
      switch (axis) {
        TERN_(X_DUAL_ENDSTOPS, case X_AXIS:)
        TERN_(Y_DUAL_ENDSTOPS, case Y_AXIS:)
        TERN_(Z_MULTI_ENDSTOPS, case Z_AXIS:)
          stepper.set_separate_multi_axis(true);
        default: break;
      }
    #endif

    //
    // Deploy BLTouch or tare the probe just before probing
    //
    #if HOMING_Z_WITH_PROBE
      if (axis == Z_AXIS) {
        if (TERN0(BLTOUCH, bltouch.deploy())) return;   // BLTouch was deployed above, but get the alarm state.
        if (TERN0(PROBE_TARE, probe.tare())) return;
      }
    #endif

    //
    // Back away to prevent an early X/Y sensorless trigger
    //
    #if DISABLED(DELTA) && defined(SENSORLESS_BACKOFF_MM)
      const xy_float_t backoff = SENSORLESS_BACKOFF_MM;
      if ((TERN0(X_SENSORLESS, axis == X_AXIS) || TERN0(Y_SENSORLESS, axis == Y_AXIS)) && backoff[axis]) {
        const float backoff_length = -ABS(backoff[axis]) * axis_home_dir;
        if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Sensorless backoff: ", backoff_length, "mm");
        do_homing_move(axis, backoff_length, homing_feedrate(axis));
      }
    #endif

    // Determine if a homing bump will be done and the bumps distance
    // When homing Z with probe respect probe clearance
    const bool use_probe_bump = TERN0(HOMING_Z_WITH_PROBE, axis == Z_AXIS && home_bump_mm(Z_AXIS));
    const float bump = axis_home_dir * (
      use_probe_bump ? _MAX(TERN0(HOMING_Z_WITH_PROBE, Z_CLEARANCE_BETWEEN_PROBES), home_bump_mm(Z_AXIS)) : home_bump_mm(axis)
    );

    //
    // Fast move towards endstop until triggered
    //
    const float move_length = 1.5f * max_length(TERN(DELTA, Z_AXIS, axis)) * axis_home_dir;
    if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Home Fast: ", move_length, "mm");
    do_homing_move(axis, move_length, 0.0, !use_probe_bump);

    #if BOTH(HOMING_Z_WITH_PROBE, BLTOUCH_SLOW_MODE)
      if (axis == Z_AXIS) bltouch.stow(); // Intermediate STOW (in LOW SPEED MODE)
    #endif

    // If a second homing move is configured...
    if (bump) {
      // Move away from the endstop by the axis HOMING_BUMP_MM
      if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Move Away: ", -bump, "mm");
      do_homing_move(axis, -bump, TERN0(HOMING_Z_WITH_PROBE, axis == Z_AXIS) ? MMM_TO_MMS(Z_PROBE_FEEDRATE_FAST) : 0, false);

      #if ENABLED(DETECT_BROKEN_ENDSTOP)
        // Check for a broken endstop
        EndstopEnum es;
        switch (axis) {
          default:
          case X_AXIS: es = X_ENDSTOP; break;
          case Y_AXIS: es = Y_ENDSTOP; break;
          case Z_AXIS: es = Z_ENDSTOP; break;
        }
        if (TEST(endstops.state(), es)) {
          SERIAL_ECHO_MSG("Bad ", axis_codes[axis], " Endstop?");
          kill(GET_TEXT(MSG_KILL_HOMING_FAILED));
        }
      #endif

      #if BOTH(HOMING_Z_WITH_PROBE, BLTOUCH_SLOW_MODE)
        if (axis == Z_AXIS && bltouch.deploy()) return; // Intermediate DEPLOY (in LOW SPEED MODE)
      #endif

      // Slow move towards endstop until triggered
      const float rebump = bump * 2;
      if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Re-bump: ", rebump, "mm");
      do_homing_move(axis, rebump, get_homing_bump_feedrate(axis), true);

      #if BOTH(HOMING_Z_WITH_PROBE, BLTOUCH)
        if (axis == Z_AXIS) bltouch.stow(); // The final STOW
      #endif
    }

    #if HAS_EXTRA_ENDSTOPS
      const bool pos_dir = axis_home_dir > 0;
      #if ENABLED(X_DUAL_ENDSTOPS)
        if (axis == X_AXIS) {
          const float adj = ABS(endstops.x2_endstop_adj);
          if (adj) {
            if (pos_dir ? (endstops.x2_endstop_adj > 0) : (endstops.x2_endstop_adj < 0)) stepper.set_x_lock(true); else stepper.set_x2_lock(true);
            do_homing_move(axis, pos_dir ? -adj : adj);
            stepper.set_x_lock(false);
            stepper.set_x2_lock(false);
          }
        }
      #endif
      #if ENABLED(Y_DUAL_ENDSTOPS)
        if (axis == Y_AXIS) {
          const float adj = ABS(endstops.y2_endstop_adj);
          if (adj) {
            if (pos_dir ? (endstops.y2_endstop_adj > 0) : (endstops.y2_endstop_adj < 0)) stepper.set_y_lock(true); else stepper.set_y2_lock(true);
            do_homing_move(axis, pos_dir ? -adj : adj);
            stepper.set_y_lock(false);
            stepper.set_y2_lock(false);
          }
        }
      #endif

      #if ENABLED(Z_MULTI_ENDSTOPS)
        if (axis == Z_AXIS) {

          #if NUM_Z_STEPPER_DRIVERS == 2

            const float adj = ABS(endstops.z2_endstop_adj);
            if (adj) {
              if (pos_dir ? (endstops.z2_endstop_adj > 0) : (endstops.z2_endstop_adj < 0)) stepper.set_z1_lock(true); else stepper.set_z2_lock(true);
              do_homing_move(axis, pos_dir ? -adj : adj);
              stepper.set_z1_lock(false);
              stepper.set_z2_lock(false);
            }

          #else

            // Handy arrays of stepper lock function pointers

            typedef void (*adjustFunc_t)(const bool);

            adjustFunc_t lock[] = {
              stepper.set_z1_lock, stepper.set_z2_lock, stepper.set_z3_lock
              #if NUM_Z_STEPPER_DRIVERS >= 4
                , stepper.set_z4_lock
              #endif
            };
            float adj[] = {
              0, endstops.z2_endstop_adj, endstops.z3_endstop_adj
              #if NUM_Z_STEPPER_DRIVERS >= 4
                , endstops.z4_endstop_adj
              #endif
            };

            adjustFunc_t tempLock;
            float tempAdj;

            // Manual bubble sort by adjust value
            if (adj[1] < adj[0]) {
              tempLock = lock[0], tempAdj = adj[0];
              lock[0] = lock[1], adj[0] = adj[1];
              lock[1] = tempLock, adj[1] = tempAdj;
            }
            if (adj[2] < adj[1]) {
              tempLock = lock[1], tempAdj = adj[1];
              lock[1] = lock[2], adj[1] = adj[2];
              lock[2] = tempLock, adj[2] = tempAdj;
            }
            #if NUM_Z_STEPPER_DRIVERS >= 4
              if (adj[3] < adj[2]) {
                tempLock = lock[2], tempAdj = adj[2];
                lock[2] = lock[3], adj[2] = adj[3];
                lock[3] = tempLock, adj[3] = tempAdj;
              }
              if (adj[2] < adj[1]) {
                tempLock = lock[1], tempAdj = adj[1];
                lock[1] = lock[2], adj[1] = adj[2];
                lock[2] = tempLock, adj[2] = tempAdj;
              }
            #endif
            if (adj[1] < adj[0]) {
              tempLock = lock[0], tempAdj = adj[0];
              lock[0] = lock[1], adj[0] = adj[1];
              lock[1] = tempLock, adj[1] = tempAdj;
            }

            if (pos_dir) {
              // normalize adj to smallest value and do the first move
              (*lock[0])(true);
              do_homing_move(axis, adj[1] - adj[0]);
              // lock the second stepper for the final correction
              (*lock[1])(true);
              do_homing_move(axis, adj[2] - adj[1]);
              #if NUM_Z_STEPPER_DRIVERS >= 4
                // lock the third stepper for the final correction
                (*lock[2])(true);
                do_homing_move(axis, adj[3] - adj[2]);
              #endif
            }
            else {
              #if NUM_Z_STEPPER_DRIVERS >= 4
                (*lock[3])(true);
                do_homing_move(axis, adj[2] - adj[3]);
              #endif
              (*lock[2])(true);
              do_homing_move(axis, adj[1] - adj[2]);
              (*lock[1])(true);
              do_homing_move(axis, adj[0] - adj[1]);
            }

            stepper.set_z1_lock(false);
            stepper.set_z2_lock(false);
            stepper.set_z3_lock(false);
            #if NUM_Z_STEPPER_DRIVERS >= 4
              stepper.set_z4_lock(false);
            #endif

          #endif
        }
      #endif

      // Reset flags for X, Y, Z motor locking
      switch (axis) {
        default: break;
        TERN_(X_DUAL_ENDSTOPS, case X_AXIS:)
        TERN_(Y_DUAL_ENDSTOPS, case Y_AXIS:)
        TERN_(Z_MULTI_ENDSTOPS, case Z_AXIS:)
          stepper.set_separate_multi_axis(false);
      }
    #endif

    #ifdef TMC_HOME_PHASE
      // move back to homing phase if configured and capable
      backout_to_tmc_homing_phase(axis);
    #endif

    #if IS_SCARA

      set_axis_is_at_home(axis);
      sync_plan_position();

    #elif ENABLED(DELTA)

      // Delta has already moved all three towers up in G28
      // so here it re-homes each tower in turn.
      // Delta homing treats the axes as normal linear axes.

      const float adjDistance = delta_endstop_adj[axis],
                  minDistance = (MIN_STEPS_PER_SEGMENT) * planner.steps_to_mm[axis];

      // Retrace by the amount specified in delta_endstop_adj if more than min steps.
      if (adjDistance * (Z_HOME_DIR) < 0 && ABS(adjDistance) > minDistance) { // away from endstop, more than min distance
        if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("adjDistance:", adjDistance);
        do_homing_move(axis, adjDistance, get_homing_bump_feedrate(axis));
      }

    #else // CARTESIAN / CORE / MARKFORGED_XY

      set_axis_is_at_home(axis);
      sync_plan_position();

      destination[axis] = current_position[axis];

      if (DEBUGGING(LEVELING)) DEBUG_POS("> AFTER set_axis_is_at_home", current_position);

    #endif

    // Put away the Z probe
    #if HOMING_Z_WITH_PROBE
      if (axis == Z_AXIS && probe.stow()) return;
    #endif

    #if DISABLED(DELTA) && defined(HOMING_BACKOFF_POST_MM)
      const xyz_float_t endstop_backoff = HOMING_BACKOFF_POST_MM;
      if (endstop_backoff[axis]) {
        current_position[axis] -= ABS(endstop_backoff[axis]) * axis_home_dir;
        line_to_current_position(
          #if HOMING_Z_WITH_PROBE
            (axis == Z_AXIS) ? z_probe_fast_mm_s :
          #endif
          homing_feedrate(axis)
        );

        #if ENABLED(SENSORLESS_HOMING)
          planner.synchronize();
          if (false
            #if EITHER(IS_CORE, MARKFORGED_XY)
              || axis != NORMAL_AXIS
            #endif
          ) safe_delay(200);  // Short delay to allow belts to spring back
        #endif
      }
    #endif

    // Clear retracted status if homing the Z axis
    #if ENABLED(FWRETRACT)
      if (axis == Z_AXIS) fwretract.current_hop = 0.0;
    #endif

    if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("<<< homeaxis(", axis_codes[axis], ")");

  } // homeaxis()

#endif // HAS_ENDSTOPS

/**
 * Set an axis' current position to its home position (after homing).
 *
 * For Core and Cartesian robots this applies one-to-one when an
 * individual axis has been homed.
 *
 * DELTA should wait until all homing is done before setting the XYZ
 * current_position to home, because homing is a single operation.
 * In the case where the axis positions are trusted and previously
 * homed, DELTA could home to X or Y individually by moving either one
 * to the center. However, homing Z always homes XY and Z.
 *
 * SCARA should wait until all XY homing is done before setting the XY
 * current_position to home, because neither X nor Y is at home until
 * both are at home. Z can however be homed individually.
 *
 * Callers must sync the planner position after calling this!
 */
void set_axis_is_at_home(const AxisEnum axis) {
  if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR(">>> set_axis_is_at_home(", AS_CHAR(axis_codes[axis]), ")");

  set_axis_trusted(axis);
  set_axis_homed(axis);

  #if ENABLED(DUAL_X_CARRIAGE)
    if (axis == X_AXIS && (active_extruder == 1 || dual_x_carriage_mode == DXC_DUPLICATION_MODE)) {
      current_position.x = x_home_pos(active_extruder);
      return;
    }
  #endif

  #if ENABLED(MORGAN_SCARA)
    scara_set_axis_is_at_home(axis);
  #elif ENABLED(DELTA)
    current_position[axis] = (axis == Z_AXIS) ? delta_height - TERN0(HAS_BED_PROBE, probe.offset.z) : base_home_pos(axis);
  #else
    current_position[axis] = base_home_pos(axis);
  #endif

  /**
   * Z Probe Z Homing? Account for the probe's Z offset.
   */
  #if HAS_BED_PROBE && Z_HOME_DIR < 0
    if (axis == Z_AXIS) {
      #if HOMING_Z_WITH_PROBE

        current_position.z -= probe.offset.z;

        if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("*** Z HOMED WITH PROBE (Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN) ***\n> probe.offset.z = ", probe.offset.z);

      #else

        if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("*** Z HOMED TO ENDSTOP ***");

      #endif
    }
  #endif

  TERN_(I2C_POSITION_ENCODERS, I2CPEM.homed(axis));

  TERN_(BABYSTEP_DISPLAY_TOTAL, babystep.reset_total(axis));

  #if HAS_POSITION_SHIFT
    position_shift[axis] = 0;
    update_workspace_offset(axis);
  #endif

  if (DEBUGGING(LEVELING)) {
    #if HAS_HOME_OFFSET
      DEBUG_ECHOLNPAIR("> home_offset[", AS_CHAR(axis_codes[axis]), "] = ", home_offset[axis]);
    #endif
    DEBUG_POS("", current_position);
    DEBUG_ECHOLNPAIR("<<< set_axis_is_at_home(", axis_codes[axis], ")");
  }
}

#if HAS_WORKSPACE_OFFSET
  void update_workspace_offset(const AxisEnum axis) {
    workspace_offset[axis] = home_offset[axis] + position_shift[axis];
    if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPAIR("Axis ", XYZ_CHAR(axis), " home_offset = ", home_offset[axis], " position_shift = ", position_shift[axis]);
  }
#endif

#if HAS_M206_COMMAND
  /**
   * Change the home offset for an axis.
   * Also refreshes the workspace offset.
   */
  void set_home_offset(const AxisEnum axis, const float v) {
    home_offset[axis] = v;
    update_workspace_offset(axis);
  }
#endif