marlin/Marlin/src/lcd/tft_io/touch_calibration.h

/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * 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/>.
 *
 */
#pragma once

#include "../../inc/MarlinConfigPre.h"
#include "tft_io.h"

#ifndef TOUCH_SCREEN_CALIBRATION_PRECISION
  #define TOUCH_SCREEN_CALIBRATION_PRECISION  80
#endif

#ifndef TOUCH_SCREEN_HOLD_TO_CALIBRATE_MS
  #define TOUCH_SCREEN_HOLD_TO_CALIBRATE_MS   2500
#endif

typedef struct __attribute__((__packed__)) {
  int32_t x, y;
  int16_t offset_x, offset_y;
  uint8_t orientation;
} touch_calibration_t;

typedef struct __attribute__((__packed__)) {
  uint16_t x, y;
  int16_t raw_x, raw_y;
} touch_calibration_point_t;

enum calibrationState : uint8_t {
  CALIBRATION_TOP_LEFT = 0x00,
  CALIBRATION_BOTTOM_LEFT,
  CALIBRATION_TOP_RIGHT,
  CALIBRATION_BOTTOM_RIGHT,
  CALIBRATION_SUCCESS,
  CALIBRATION_FAIL,
  CALIBRATION_NONE,
};

class TouchCalibration {
public:
  static calibrationState calibration_state;
  static touch_calibration_point_t calibration_points[4];

  static bool validate_precision(int32_t a, int32_t b) { return (a > b ? (100 * b) / a :  (100 * a) / b) > TOUCH_SCREEN_CALIBRATION_PRECISION; }
  static bool validate_precision_x(uint8_t a, uint8_t b) { return validate_precision(calibration_points[a].raw_x, calibration_points[b].raw_x); }
  static bool validate_precision_y(uint8_t a, uint8_t b) { return validate_precision(calibration_points[a].raw_y, calibration_points[b].raw_y); }
  static void validate_calibration();

  static touch_calibration_t calibration;
  static uint8_t             failed_count;
  static void calibration_reset() { calibration = { TOUCH_CALIBRATION_X, TOUCH_CALIBRATION_Y, TOUCH_OFFSET_X, TOUCH_OFFSET_Y, TOUCH_ORIENTATION }; }
  static bool need_calibration() { return !calibration.offset_x && !calibration.offset_y && !calibration.x && !calibration.y; }

  static calibrationState calibration_start() {
    calibration = { 0, 0, 0, 0, TOUCH_ORIENTATION_NONE };
    calibration_state = CALIBRATION_TOP_LEFT;
    calibration_points[CALIBRATION_TOP_LEFT].x = 30;
    calibration_points[CALIBRATION_TOP_LEFT].y = 30;
    calibration_points[CALIBRATION_BOTTOM_LEFT].x = 30;
    calibration_points[CALIBRATION_BOTTOM_LEFT].y = TFT_HEIGHT - 31;
    calibration_points[CALIBRATION_TOP_RIGHT].x = TFT_WIDTH - 31;
    calibration_points[CALIBRATION_TOP_RIGHT].y = 30;
    calibration_points[CALIBRATION_BOTTOM_RIGHT].x = TFT_WIDTH - 31;
    calibration_points[CALIBRATION_BOTTOM_RIGHT].y = TFT_HEIGHT - 31;
    failed_count = 0;
    return calibration_state;
  }
  static void calibration_end() { calibration_state = CALIBRATION_NONE; }
  static calibrationState get_calibration_state() { return calibration_state; }
  static bool calibration_loaded() {
    if (need_calibration()) calibration_reset();
    return !need_calibration();
  }

  static bool handleTouch(uint16_t x, uint16_t y);
};

extern TouchCalibration touch_calibration;