/**
* Marlin 3D Printer Firmware
* Copyright (C) 2016 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 <http://www.gnu.org/licenses/>.
*
*/
#include "MarlinConfig.h"
#if ENABLED(AUTO_BED_LEVELING_UBL)
#include "Marlin.h"
#include "ubl.h"
#include "planner.h"
#include "stepper.h"
#include <avr/io.h>
#include <math.h>
#if AVR_AT90USB1286_FAMILY // Teensyduino & Printrboard IDE extensions have compile errors without this
inline void set_current_from_destination() { COPY(current_position, destination); }
#else
extern void set_current_from_destination();
#endif
#if !UBL_SEGMENTED
void unified_bed_leveling::line_to_destination_cartesian(const float &feed_rate, const uint8_t extruder) {
/**
* Much of the nozzle movement will be within the same cell. So we will do as little computation
* as possible to determine if this is the case. If this move is within the same cell, we will
* just do the required Z-Height correction, call the Planner's buffer_line() routine, and leave
*/
#if ENABLED(SKEW_CORRECTION)
// For skew correction just adjust the destination point and we're done
float start[XYZE] = { current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS] },
end[XYZE] = { destination[X_AXIS], destination[Y_AXIS], destination[Z_AXIS], destination[E_AXIS] };
planner.skew(start[X_AXIS], start[Y_AXIS], start[Z_AXIS]);
planner.skew(end[X_AXIS], end[Y_AXIS], end[Z_AXIS]);
#else
const float (&start)[XYZE] = current_position,
(&end)[XYZE] = destination;
#endif
const int cell_start_xi = get_cell_index_x(start[X_AXIS]),
cell_start_yi = get_cell_index_y(start[Y_AXIS]),
cell_dest_xi = get_cell_index_x(end[X_AXIS]),
cell_dest_yi = get_cell_index_y(end[Y_AXIS]);
if (g26_debug_flag) {
SERIAL_ECHOPAIR(" ubl.line_to_destination_cartesian(xe=", destination[X_AXIS]);
SERIAL_ECHOPAIR(", ye=", destination[Y_AXIS]);
SERIAL_ECHOPAIR(", ze=", destination[Z_AXIS]);
SERIAL_ECHOPAIR(", ee=", destination[E_AXIS]);
SERIAL_CHAR(')');
SERIAL_EOL();
debug_current_and_destination(PSTR("Start of ubl.line_to_destination_cartesian()"));
}
if (cell_start_xi == cell_dest_xi && cell_start_yi == cell_dest_yi) { // if the whole move is within the same cell,
// we don't need to break up the move
/**
* If we are moving off the print bed, we are going to allow the move at this level.
* But we detect it and isolate it. For now, we just pass along the request.
*/
if (!WITHIN(cell_dest_xi, 0, GRID_MAX_POINTS_X - 1) || !WITHIN(cell_dest_yi, 0, GRID_MAX_POINTS_Y - 1)) {
// Note: There is no Z Correction in this case. We are off the grid and don't know what
// a reasonable correction would be. If the user has specified a UBL_Z_RAISE_WHEN_OFF_MESH
// value, that will be used instead of a calculated (Bi-Linear interpolation) correction.
const float z_raise = 0.0
#ifdef UBL_Z_RAISE_WHEN_OFF_MESH
+ UBL_Z_RAISE_WHEN_OFF_MESH
#endif
;
planner.buffer_segment(end[X_AXIS], end[Y_AXIS], end[Z_AXIS] + z_raise, end[E_AXIS], feed_rate, extruder);
set_current_from_destination();
if (g26_debug_flag)
debug_current_and_destination(PSTR("out of bounds in ubl.line_to_destination_cartesian()"));
return;
}
FINAL_MOVE:
/**
* Optimize some floating point operations here. We could call float get_z_correction(float x0, float y0) to
* generate the correction for us. But we can lighten the load on the CPU by doing a modified version of the function.
* We are going to only calculate the amount we are from the first mesh line towards the second mesh line once.
* We will use this fraction in both of the original two Z Height calculations for the bi-linear interpolation. And,
* instead of doing a generic divide of the distance, we know the distance is MESH_X_DIST so we can use the preprocessor
* to create a 1-over number for us. That will allow us to do a floating point multiply instead of a floating point divide.
*/
const float xratio = (end[X_AXIS] - mesh_index_to_xpos(cell_dest_xi)) * (1.0 / (MESH_X_DIST));
float z1 = z_values[cell_dest_xi ][cell_dest_yi ] + xratio *
(z_values[cell_dest_xi + 1][cell_dest_yi ] - z_values[cell_dest_xi][cell_dest_yi ]),
z2 = z_values[cell_dest_xi ][cell_dest_yi + 1] + xratio *
(z_values[cell_dest_xi + 1][cell_dest_yi + 1] - z_values[cell_dest_xi][cell_dest_yi + 1]);
if (cell_dest_xi >= GRID_MAX_POINTS_X - 1) z1 = z2 = 0.0;
// we are done with the fractional X distance into the cell. Now with the two Z-Heights we have calculated, we
// are going to apply the Y-Distance into the cell to interpolate the final Z correction.
const float yratio = (end[Y_AXIS] - mesh_index_to_ypos(cell_dest_yi)) * (1.0 / (MESH_Y_DIST));
float z0 = cell_dest_yi < GRID_MAX_POINTS_Y - 1 ? (z1 + (z2 - z1) * yratio) * planner.fade_scaling_factor_for_z(end[Z_AXIS]) : 0.0;
/**
* If part of the Mesh is undefined, it will show up as NAN
* in z_values[][] and propagate through the
* calculations. If our correction is NAN, we throw it out
* because part of the Mesh is undefined and we don't have the
* information we need to complete the height correction.
*/
if (isnan(z0)) z0 = 0.0;
planner.buffer_segment(end[X_AXIS], end[Y_AXIS], end[Z_AXIS] + z0, end[E_AXIS], feed_rate, extruder);
if (g26_debug_flag)
debug_current_and_destination(PSTR("FINAL_MOVE in ubl.line_to_destination_cartesian()"));
set_current_from_destination();
return;
}
/**
* If we get here, we are processing a move that crosses at least one Mesh Line. We will check
* for the simple case of just crossing X or just crossing Y Mesh Lines after we get all the details
* of the move figured out. We can process the easy case of just crossing an X or Y Mesh Line with less
* computation and in fact most lines are of this nature. We will check for that in the following
* blocks of code:
*/
const float dx = end[X_AXIS] - start[X_AXIS],
dy = end[Y_AXIS] - start[Y_AXIS];
const int left_flag = dx < 0.0 ? 1 : 0,
down_flag = dy < 0.0 ? 1 : 0;
const float adx = left_flag ? -dx : dx,
ady = down_flag ? -dy : dy;
const int dxi = cell_start_xi == cell_dest_xi ? 0 : left_flag ? -1 : 1,
dyi = cell_start_yi == cell_dest_yi ? 0 : down_flag ? -1 : 1;
/**
* Compute the scaling factor for the extruder for each partial move.
* We need to watch out for zero length moves because it will cause us to
* have an infinate scaling factor. We are stuck doing a floating point
* divide to get our scaling factor, but after that, we just multiply by this
* number. We also pick our scaling factor based on whether the X or Y
* component is larger. We use the biggest of the two to preserve precision.
*/
const bool use_x_dist = adx > ady;
float on_axis_distance = use_x_dist ? dx : dy,
e_position = end[E_AXIS] - start[E_AXIS],
z_position = end[Z_AXIS] - start[Z_AXIS];
const float e_normalized_dist = e_position / on_axis_distance,
z_normalized_dist = z_position / on_axis_distance;
int current_xi = cell_start_xi,
current_yi = cell_start_yi;
const float m = dy / dx,
c = start[Y_AXIS] - m * start[X_AXIS];
const bool inf_normalized_flag = (isinf(e_normalized_dist) != 0),
inf_m_flag = (isinf(m) != 0);
/**
* This block handles vertical lines. These are lines that stay within the same
* X Cell column. They do not need to be perfectly vertical. They just can
* not cross into another X Cell column.
*/
if (dxi == 0) { // Check for a vertical line
current_yi += down_flag; // Line is heading down, we just want to go to the bottom
while (current_yi != cell_dest_yi + down_flag) {
current_yi += dyi;
const float next_mesh_line_y = mesh_index_to_ypos(current_yi);
/**
* if the slope of the line is infinite, we won't do the calculations
* else, we know the next X is the same so we can recover and continue!
* Calculate X at the next Y mesh line
*/
const float rx = inf_m_flag ? start[X_AXIS] : (next_mesh_line_y - c) / m;
float z0 = z_correction_for_x_on_horizontal_mesh_line(rx, current_xi, current_yi)
* planner.fade_scaling_factor_for_z(end[Z_AXIS]);
/**
* If part of the Mesh is undefined, it will show up as NAN
* in z_values[][] and propagate through the
* calculations. If our correction is NAN, we throw it out
* because part of the Mesh is undefined and we don't have the
* information we need to complete the height correction.
*/
if (isnan(z0)) z0 = 0.0;
const float ry = mesh_index_to_ypos(current_yi);
/**
* Without this check, it is possible for the algorithm to generate a zero length move in the case
* where the line is heading down and it is starting right on a Mesh Line boundary. For how often that
* happens, it might be best to remove the check and always 'schedule' the move because
* the planner.buffer_segment() routine will filter it if that happens.
*/
if (ry != start[Y_AXIS]) {
if (!inf_normalized_flag) {
on_axis_distance = use_x_dist ? rx - start[X_AXIS] : ry - start[Y_AXIS];
e_position = start[E_AXIS] + on_axis_distance * e_normalized_dist;
z_position = start[Z_AXIS] + on_axis_distance * z_normalized_dist;
}
else {
e_position = end[E_AXIS];
z_position = end[Z_AXIS];
}
planner.buffer_segment(rx, ry, z_position + z0, e_position, feed_rate, extruder);
} //else printf("FIRST MOVE PRUNED ");
}
if (g26_debug_flag)
debug_current_and_destination(PSTR("vertical move done in ubl.line_to_destination_cartesian()"));
//
// Check if we are at the final destination. Usually, we won't be, but if it is on a Y Mesh Line, we are done.
//
if (current_position[X_AXIS] != end[X_AXIS] || current_position[Y_AXIS] != end[Y_AXIS])
goto FINAL_MOVE;
set_current_from_destination();
return;
}
/**
*
* This block handles horizontal lines. These are lines that stay within the same
* Y Cell row. They do not need to be perfectly horizontal. They just can
* not cross into another Y Cell row.
*
*/
if (dyi == 0) { // Check for a horizontal line
current_xi += left_flag; // Line is heading left, we just want to go to the left
// edge of this cell for the first move.
while (current_xi != cell_dest_xi + left_flag) {
current_xi += dxi;
const float next_mesh_line_x = mesh_index_to_xpos(current_xi),
ry = m * next_mesh_line_x + c; // Calculate Y at the next X mesh line
float z0 = z_correction_for_y_on_vertical_mesh_line(ry, current_xi, current_yi)
* planner.fade_scaling_factor_for_z(end[Z_AXIS]);
/**
* If part of the Mesh is undefined, it will show up as NAN
* in z_values[][] and propagate through the
* calculations. If our correction is NAN, we throw it out
* because part of the Mesh is undefined and we don't have the
* information we need to complete the height correction.
*/
if (isnan(z0)) z0 = 0.0;
const float rx = mesh_index_to_xpos(current_xi);
/**
* Without this check, it is possible for the algorithm to generate a zero length move in the case
* where the line is heading left and it is starting right on a Mesh Line boundary. For how often
* that happens, it might be best to remove the check and always 'schedule' the move because
* the planner.buffer_segment() routine will filter it if that happens.
*/
if (rx != start[X_AXIS]) {
if (!inf_normalized_flag) {
on_axis_distance = use_x_dist ? rx - start[X_AXIS] : ry - start[Y_AXIS];
e_position = start[E_AXIS] + on_axis_distance * e_normalized_dist; // is based on X or Y because this is a horizontal move
z_position = start[Z_AXIS] + on_axis_distance * z_normalized_dist;
}
else {
e_position = end[E_AXIS];
z_position = end[Z_AXIS];
}
planner.buffer_segment(rx, ry, z_position + z0, e_position, feed_rate, extruder);
} //else printf("FIRST MOVE PRUNED ");
}
if (g26_debug_flag)
debug_current_and_destination(PSTR("horizontal move done in ubl.line_to_destination_cartesian()"));
if (current_position[X_AXIS] != end[X_AXIS] || current_position[Y_AXIS] != end[Y_AXIS])
goto FINAL_MOVE;
set_current_from_destination();
return;
}
/**
*
* This block handles the generic case of a line crossing both X and Y Mesh lines.
*
*/
int xi_cnt = cell_start_xi - cell_dest_xi,
yi_cnt = cell_start_yi - cell_dest_yi;
if (xi_cnt < 0) xi_cnt = -xi_cnt;
if (yi_cnt < 0) yi_cnt = -yi_cnt;
current_xi += left_flag;
current_yi += down_flag;
while (xi_cnt > 0 || yi_cnt > 0) {
const float next_mesh_line_x = mesh_index_to_xpos(current_xi + dxi),
next_mesh_line_y = mesh_index_to_ypos(current_yi + dyi),
ry = m * next_mesh_line_x + c, // Calculate Y at the next X mesh line
rx = (next_mesh_line_y - c) / m; // Calculate X at the next Y mesh line
// (No need to worry about m being zero.
// If that was the case, it was already detected
// as a vertical line move above.)
if (left_flag == (rx > next_mesh_line_x)) { // Check if we hit the Y line first
// Yes! Crossing a Y Mesh Line next
float z0 = z_correction_for_x_on_horizontal_mesh_line(rx, current_xi - left_flag, current_yi + dyi)
* planner.fade_scaling_factor_for_z(end[Z_AXIS]);
/**
* If part of the Mesh is undefined, it will show up as NAN
* in z_values[][] and propagate through the
* calculations. If our correction is NAN, we throw it out
* because part of the Mesh is undefined and we don't have the
* information we need to complete the height correction.
*/
if (isnan(z0)) z0 = 0.0;
if (!inf_normalized_flag) {
on_axis_distance = use_x_dist ? rx - start[X_AXIS] : next_mesh_line_y - start[Y_AXIS];
e_position = start[E_AXIS] + on_axis_distance * e_normalized_dist;
z_position = start[Z_AXIS] + on_axis_distance * z_normalized_dist;
}
else {
e_position = end[E_AXIS];
z_position = end[Z_AXIS];
}
planner.buffer_segment(rx, next_mesh_line_y, z_position + z0, e_position, feed_rate, extruder);
current_yi += dyi;
yi_cnt--;
}
else {
// Yes! Crossing a X Mesh Line next
float z0 = z_correction_for_y_on_vertical_mesh_line(ry, current_xi + dxi, current_yi - down_flag)
* planner.fade_scaling_factor_for_z(end[Z_AXIS]);
/**
* If part of the Mesh is undefined, it will show up as NAN
* in z_values[][] and propagate through the
* calculations. If our correction is NAN, we throw it out
* because part of the Mesh is undefined and we don't have the
* information we need to complete the height correction.
*/
if (isnan(z0)) z0 = 0.0;
if (!inf_normalized_flag) {
on_axis_distance = use_x_dist ? next_mesh_line_x - start[X_AXIS] : ry - start[Y_AXIS];
e_position = start[E_AXIS] + on_axis_distance * e_normalized_dist;
z_position = start[Z_AXIS] + on_axis_distance * z_normalized_dist;
}
else {
e_position = end[E_AXIS];
z_position = end[Z_AXIS];
}
planner.buffer_segment(next_mesh_line_x, ry, z_position + z0, e_position, feed_rate, extruder);
current_xi += dxi;
xi_cnt--;
}
if (xi_cnt < 0 || yi_cnt < 0) break; // we've gone too far, so exit the loop and move on to FINAL_MOVE
}
if (g26_debug_flag)
debug_current_and_destination(PSTR("generic move done in ubl.line_to_destination_cartesian()"));
if (current_position[X_AXIS] != end[X_AXIS] || current_position[Y_AXIS] != end[Y_AXIS])
goto FINAL_MOVE;
set_current_from_destination();
}
#else // UBL_SEGMENTED
#if IS_SCARA // scale the feed rate from mm/s to degrees/s
static float scara_feed_factor, scara_oldA, scara_oldB;
#endif
// We don't want additional apply_leveling() performed by regular buffer_line or buffer_line_kinematic,
// so we call buffer_segment directly here. Per-segmented leveling and kinematics performed first.
inline void _O2 ubl_buffer_segment_raw(const float (&in_raw)[XYZE], const float &fr) {
#if ENABLED(SKEW_CORRECTION)
float raw[XYZE] = { in_raw[X_AXIS], in_raw[Y_AXIS], in_raw[Z_AXIS], in_raw[E_AXIS] };
planner.skew(raw[X_AXIS], raw[Y_AXIS], raw[Z_AXIS]);
#else
const float (&raw)[XYZE] = in_raw;
#endif
#if ENABLED(DELTA) // apply delta inverse_kinematics
DELTA_IK(raw);
planner.buffer_segment(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], in_raw[E_AXIS], fr, active_extruder);
#elif IS_SCARA // apply scara inverse_kinematics (should be changed to save raw->logical->raw)
inverse_kinematics(raw); // this writes delta[ABC] from raw[XYZE]
// should move the feedrate scaling to scara inverse_kinematics
const float adiff = FABS(delta[A_AXIS] - scara_oldA),
bdiff = FABS(delta[B_AXIS] - scara_oldB);
scara_oldA = delta[A_AXIS];
scara_oldB = delta[B_AXIS];
float s_feedrate = max(adiff, bdiff) * scara_feed_factor;
planner.buffer_segment(delta[A_AXIS], delta[B_AXIS], delta[C_AXIS], in_raw[E_AXIS], s_feedrate, active_extruder);
#else // CARTESIAN
planner.buffer_segment(raw[X_AXIS], raw[Y_AXIS], raw[Z_AXIS], in_raw[E_AXIS], fr, active_extruder);
#endif
}
#if IS_SCARA
#define DELTA_SEGMENT_MIN_LENGTH 0.25 // SCARA minimum segment size is 0.25mm
#elif ENABLED(DELTA)
#define DELTA_SEGMENT_MIN_LENGTH 0.10 // mm (still subject to DELTA_SEGMENTS_PER_SECOND)
#else // CARTESIAN
#ifdef LEVELED_SEGMENT_LENGTH
#define DELTA_SEGMENT_MIN_LENGTH LEVELED_SEGMENT_LENGTH
#else
#define DELTA_SEGMENT_MIN_LENGTH 1.00 // mm (similar to G2/G3 arc segmentation)
#endif
#endif
/**
* Prepare a segmented linear move for DELTA/SCARA/CARTESIAN with UBL and FADE semantics.
* This calls planner.buffer_segment multiple times for small incremental moves.
* Returns true if did NOT move, false if moved (requires current_position update).
*/
bool _O2 unified_bed_leveling::prepare_segmented_line_to(const float (&rtarget)[XYZE], const float &feedrate) {
if (!position_is_reachable(rtarget[X_AXIS], rtarget[Y_AXIS])) // fail if moving outside reachable boundary
return true; // did not move, so current_position still accurate
const float total[XYZE] = {
rtarget[X_AXIS] - current_position[X_AXIS],
rtarget[Y_AXIS] - current_position[Y_AXIS],
rtarget[Z_AXIS] - current_position[Z_AXIS],
rtarget[E_AXIS] - current_position[E_AXIS]
};
const float cartesian_xy_mm = HYPOT(total[X_AXIS], total[Y_AXIS]); // total horizontal xy distance
#if IS_KINEMATIC
const float seconds = cartesian_xy_mm / feedrate; // seconds to move xy distance at requested rate
uint16_t segments = lroundf(delta_segments_per_second * seconds), // preferred number of segments for distance @ feedrate
seglimit = lroundf(cartesian_xy_mm * (1.0 / (DELTA_SEGMENT_MIN_LENGTH))); // number of segments at minimum segment length
NOMORE(segments, seglimit); // limit to minimum segment length (fewer segments)
#else
uint16_t segments = lroundf(cartesian_xy_mm * (1.0 / (DELTA_SEGMENT_MIN_LENGTH))); // cartesian fixed segment length
#endif
NOLESS(segments, 1); // must have at least one segment
const float inv_segments = 1.0 / segments; // divide once, multiply thereafter
#if IS_SCARA // scale the feed rate from mm/s to degrees/s
scara_feed_factor = cartesian_xy_mm * inv_segments * feedrate;
scara_oldA = stepper.get_axis_position_degrees(A_AXIS);
scara_oldB = stepper.get_axis_position_degrees(B_AXIS);
#endif
const float diff[XYZE] = {
total[X_AXIS] * inv_segments,
total[Y_AXIS] * inv_segments,
total[Z_AXIS] * inv_segments,
total[E_AXIS] * inv_segments
};
// Note that E segment distance could vary slightly as z mesh height
// changes for each segment, but small enough to ignore.
float raw[XYZE] = {
current_position[X_AXIS],
current_position[Y_AXIS],
current_position[Z_AXIS],
current_position[E_AXIS]
};
// Only compute leveling per segment if ubl active and target below z_fade_height.
if (!planner.leveling_active || !planner.leveling_active_at_z(rtarget[Z_AXIS])) { // no mesh leveling
while (--segments) {
LOOP_XYZE(i) raw[i] += diff[i];
ubl_buffer_segment_raw(raw, feedrate);
}
ubl_buffer_segment_raw(rtarget, feedrate);
return false; // moved but did not set_current_from_destination();
}
// Otherwise perform per-segment leveling
#if ENABLED(ENABLE_LEVELING_FADE_HEIGHT)
const float fade_scaling_factor = planner.fade_scaling_factor_for_z(rtarget[Z_AXIS]);
#endif
// increment to first segment destination
LOOP_XYZE(i) raw[i] += diff[i];
for(;;) { // for each mesh cell encountered during the move
// Compute mesh cell invariants that remain constant for all segments within cell.
// Note for cell index, if point is outside the mesh grid (in MESH_INSET perimeter)
// the bilinear interpolation from the adjacent cell within the mesh will still work.
// Inner loop will exit each time (because out of cell bounds) but will come back
// in top of loop and again re-find same adjacent cell and use it, just less efficient
// for mesh inset area.
int8_t cell_xi = (raw[X_AXIS] - (MESH_MIN_X)) * (1.0 / (MESH_X_DIST)),
cell_yi = (raw[Y_AXIS] - (MESH_MIN_Y)) * (1.0 / (MESH_X_DIST));
cell_xi = constrain(cell_xi, 0, (GRID_MAX_POINTS_X) - 1);
cell_yi = constrain(cell_yi, 0, (GRID_MAX_POINTS_Y) - 1);
const float x0 = mesh_index_to_xpos(cell_xi), // 64 byte table lookup avoids mul+add
y0 = mesh_index_to_ypos(cell_yi);
float z_x0y0 = z_values[cell_xi ][cell_yi ], // z at lower left corner
z_x1y0 = z_values[cell_xi+1][cell_yi ], // z at upper left corner
z_x0y1 = z_values[cell_xi ][cell_yi+1], // z at lower right corner
z_x1y1 = z_values[cell_xi+1][cell_yi+1]; // z at upper right corner
if (isnan(z_x0y0)) z_x0y0 = 0; // ideally activating planner.leveling_active (G29 A)
if (isnan(z_x1y0)) z_x1y0 = 0; // should refuse if any invalid mesh points
if (isnan(z_x0y1)) z_x0y1 = 0; // in order to avoid isnan tests per cell,
if (isnan(z_x1y1)) z_x1y1 = 0; // thus guessing zero for undefined points
float cx = raw[X_AXIS] - x0, // cell-relative x and y
cy = raw[Y_AXIS] - y0;
const float z_xmy0 = (z_x1y0 - z_x0y0) * (1.0 / (MESH_X_DIST)), // z slope per x along y0 (lower left to lower right)
z_xmy1 = (z_x1y1 - z_x0y1) * (1.0 / (MESH_X_DIST)); // z slope per x along y1 (upper left to upper right)
float z_cxy0 = z_x0y0 + z_xmy0 * cx; // z height along y0 at cx (changes for each cx in cell)
const float z_cxy1 = z_x0y1 + z_xmy1 * cx, // z height along y1 at cx
z_cxyd = z_cxy1 - z_cxy0; // z height difference along cx from y0 to y1
float z_cxym = z_cxyd * (1.0 / (MESH_Y_DIST)); // z slope per y along cx from y0 to y1 (changes for each cx in cell)
// float z_cxcy = z_cxy0 + z_cxym * cy; // interpolated mesh z height along cx at cy (do inside the segment loop)
// As subsequent segments step through this cell, the z_cxy0 intercept will change
// and the z_cxym slope will change, both as a function of cx within the cell, and
// each change by a constant for fixed segment lengths.
const float z_sxy0 = z_xmy0 * diff[X_AXIS], // per-segment adjustment to z_cxy0
z_sxym = (z_xmy1 - z_xmy0) * (1.0 / (MESH_Y_DIST)) * diff[X_AXIS]; // per-segment adjustment to z_cxym
for(;;) { // for all segments within this mesh cell
if (--segments == 0) // if this is last segment, use rtarget for exact
COPY(raw, rtarget);
const float z_cxcy = (z_cxy0 + z_cxym * cy) // interpolated mesh z height along cx at cy
#if ENABLED(ENABLE_LEVELING_FADE_HEIGHT)
* fade_scaling_factor // apply fade factor to interpolated mesh height
#endif
;
const float z = raw[Z_AXIS];
raw[Z_AXIS] += z_cxcy;
ubl_buffer_segment_raw(raw, feedrate);
raw[Z_AXIS] = z;
if (segments == 0) // done with last segment
return false; // did not set_current_from_destination()
LOOP_XYZE(i) raw[i] += diff[i];
cx += diff[X_AXIS];
cy += diff[Y_AXIS];
if (!WITHIN(cx, 0, MESH_X_DIST) || !WITHIN(cy, 0, MESH_Y_DIST)) // done within this cell, break to next
break;
// Next segment still within same mesh cell, adjust the per-segment
// slope and intercept to compute next z height.
z_cxy0 += z_sxy0; // adjust z_cxy0 by per-segment z_sxy0
z_cxym += z_sxym; // adjust z_cxym by per-segment z_sxym
} // segment loop
} // cell loop
return false; // caller will update current_position
}
#endif // UBL_SEGMENTED
#endif // AUTO_BED_LEVELING_UBL