♻️ Rename XATC z_values => z_offset

Marlin/src/feature/bedlevel/abl/x_twist.cpp

 XATC xatc;
 
 float XATC::spacing, XATC::start;
-xatc_points_t XATC::z_values;
+xatc_array_t XATC::z_offset;
 
 void XATC::print_points() {
   SERIAL_ECHOLNPGM(" X-Twist Correction:");
   LOOP_L_N(x, XATC_MAX_POINTS) {
     SERIAL_CHAR(' ');
-    if (!isnan(z_values[x])) {
-      if (z_values[x] >= 0) SERIAL_CHAR('+');
-      SERIAL_ECHO_F(z_values[x], 3);
+    if (!isnan(z_offset[x])) {
+      if (z_offset[x] >= 0) SERIAL_CHAR('+');
+      SERIAL_ECHO_F(z_offset[x], 3);
     }
     else {
       LOOP_L_N(i, 6)
   int i = FLOOR(t);
   LIMIT(i, 0, XATC_MAX_POINTS - 2);
   t -= i;
-  return lerp(t, z_values[i], z_values[i + 1]);
+  return lerp(t, z_offset[i], z_offset[i + 1]);
 }
 
 #endif // X_AXIS_TWIST_COMPENSATION

Marlin/src/feature/bedlevel/abl/x_twist.h

 
 #include "../../../inc/MarlinConfigPre.h"
 
-typedef float xatc_points_t[XATC_MAX_POINTS];
+typedef float xatc_array_t[XATC_MAX_POINTS];
 
 class XATC {
 public:
   static float spacing, start;
-  static xatc_points_t z_values;
+  static xatc_array_t z_offset;
 
   static float compensation(const xy_pos_t &raw);
   static void print_points();

Marlin/src/lcd/menu/menu_x_twist.cpp

 //
 void xatc_wizard_set_offset_and_go_to_next_point() {
   // Set Z-offset at probed point
-  xatc.z_values[manual_probe_index++] = probe.offset.z + current_position.z - measured_z;
+  xatc.z_offset[manual_probe_index++] = probe.offset.z + current_position.z - measured_z;
   // Go to next point
   ui.goto_screen(xatc_wizard_goto_next_point);
 }
   else {
     // Compute the z-offset by averaging the values found with this wizard
     z_offset = 0;
-    LOOP_L_N(i, XATC_MAX_POINTS) z_offset += xatc.z_values[i];
+    LOOP_L_N(i, XATC_MAX_POINTS) z_offset += xatc.z_offset[i];
     z_offset /= XATC_MAX_POINTS;
 
     // Subtract the average from the values found with this wizard.
     // This way they are indipendent from the z-offset
-    LOOP_L_N(i, XATC_MAX_POINTS) xatc.z_values[i] -= z_offset;
+    LOOP_L_N(i, XATC_MAX_POINTS) xatc.z_offset[i] -= z_offset;
 
     ui.goto_screen(xatc_wizard_update_z_offset);
   }

Marlin/src/module/settings.cpp

           "Bilinear Z array is the wrong size."
         );
         #if ENABLED(X_AXIS_TWIST_COMPENSATION)
-          static_assert(
-            sizeof(xatc.z_values) == (XATC_MAX_POINTS) * sizeof(xatc.z_values[0]),
-            "Z-offset mesh is the wrong size."
-          );
+          static_assert(COUNT(xatc.z_offset) == XATC_MAX_POINTS, "XATC Z-offset mesh is the wrong size.");
         #endif
       #else
         const xy_pos_t bilinear_start{0}, bilinear_grid_spacing{0};