marlin/Marlin/src/feature/x_twist.cpp

/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2021 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/>.
 *
 */
#include "../inc/MarlinConfig.h"

#if ENABLED(X_AXIS_TWIST_COMPENSATION)

#include "x_twist.h"
#include "../module/probe.h"

XATC xatc;

bool XATC::enabled;
float XATC::spacing, XATC::start;
xatc_array_t XATC::z_offset; // Initialized by settings.load()

void XATC::reset() {
  constexpr float xzo[] = XATC_Z_OFFSETS;
  static_assert(COUNT(xzo) == XATC_MAX_POINTS, "XATC_Z_OFFSETS is the wrong size.");
  COPY(z_offset, xzo);
  start = probe.min_x();
  spacing = (probe.max_x() - start) / (XATC_MAX_POINTS - 1);
  enabled = true;
}

void XATC::print_points() {
  SERIAL_ECHOLNPGM(" X-Twist Correction:");
  LOOP_L_N(x, XATC_MAX_POINTS) {
    SERIAL_CHAR(' ');
    if (!isnan(z_offset[x]))
      serial_offset(z_offset[x]);
    else
      LOOP_L_N(i, 6) SERIAL_CHAR(i ? '=' : ' ');
  }
  SERIAL_EOL();
}

float lerp(const_float_t t, const_float_t a, const_float_t b) { return a + t * (b - a); }

float XATC::compensation(const xy_pos_t &raw) {
  if (!enabled) return 0;
  if (NEAR_ZERO(spacing)) return 0;
  float t = (raw.x - start) / spacing;
  const int i = constrain(FLOOR(t), 0, XATC_MAX_POINTS - 2);
  t -= i;
  return lerp(t, z_offset[i], z_offset[i + 1]);
}

#endif // X_AXIS_TWIST_COMPENSATION