Merge G29 Ending Position (PR#2498)

Marlin/Marlin_main.cpp

     feedrate = oldFeedRate;
   }
 
+  inline void do_blocking_move_to_xy(float x, float y) { do_blocking_move_to(x, y, current_position[Z_AXIS]); }
+  inline void do_blocking_move_to_x(float x) { do_blocking_move_to(x, current_position[Y_AXIS], current_position[Z_AXIS]); }
+  inline void do_blocking_move_to_z(float z) { do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], z); }
+
   static void clean_up_after_endstop_move() {
     #ifdef ENDSTOPS_ONLY_FOR_HOMING
       enable_endstops(false);
 
         #if Z_RAISE_AFTER_PROBING > 0
           if (doRaise) {
-            do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS] + Z_RAISE_AFTER_PROBING); // this also updates current_position
+            do_blocking_move_to_z(current_position[Z_AXIS] + Z_RAISE_AFTER_PROBING); // this also updates current_position
             st_synchronize();
           }
         #endif
   // Probe bed height at position (x,y), returns the measured z value
   static float probe_pt(float x, float y, float z_before, ProbeAction probe_action=ProbeDeployAndStow, int verbose_level=1) {
     // Move Z up to the z_before height, then move the probe to the given XY
-    do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], z_before); // this also updates current_position
-    do_blocking_move_to(x - X_PROBE_OFFSET_FROM_EXTRUDER, y - Y_PROBE_OFFSET_FROM_EXTRUDER, current_position[Z_AXIS]); // this also updates current_position
+    do_blocking_move_to_z(z_before); // this also updates current_position
+    do_blocking_move_to_xy(x - X_PROBE_OFFSET_FROM_EXTRUDER, y - Y_PROBE_OFFSET_FROM_EXTRUDER); // this also updates current_position
 
     #if !defined(Z_PROBE_SLED) && !defined(Z_PROBE_ALLEN_KEY)
       if (probe_action & ProbeDeploy) deploy_z_probe();
       return;
     }
 
+    float oldXpos = current_position[X_AXIS]; // save x position
     if (dock) {
-      float oldXpos = current_position[X_AXIS]; // save x position
-      do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS] + Z_RAISE_AFTER_PROBING); // rise Z   
-      do_blocking_move_to(X_MAX_POS + SLED_DOCKING_OFFSET + offset - 1, current_position[Y_AXIS], current_position[Z_AXIS]);  // Dock sled a bit closer to ensure proper capturing                                                                                                                           
+      do_blocking_move_to_z(current_position[Z_AXIS] + Z_RAISE_AFTER_PROBING); // raise Z   
+      do_blocking_move_to_x(X_MAX_POS + SLED_DOCKING_OFFSET + offset - 1);  // Dock sled a bit closer to ensure proper capturing
       digitalWrite(SLED_PIN, LOW); // turn off magnet
-      do_blocking_move_to(oldXpos, current_position[Y_AXIS], current_position[Z_AXIS]); // return to position before docking
     } else {
-      float oldXpos = current_position[X_AXIS]; // save x position
       float z_loc = current_position[Z_AXIS];
       if (z_loc < Z_RAISE_BEFORE_PROBING + 5) z_loc = Z_RAISE_BEFORE_PROBING;
       do_blocking_move_to(X_MAX_POS + SLED_DOCKING_OFFSET + offset, current_position[Y_AXIS], z_loc); // this also updates current_position
       digitalWrite(SLED_PIN, HIGH); // turn on magnet
-      do_blocking_move_to(oldXpos, current_position[Y_AXIS], current_position[Z_AXIS]); // return to position before docking
     }
+    do_blocking_move_to_x(oldXpos); // return to position before docking
   }
 
 #endif // Z_PROBE_SLED
         float x_tmp = current_position[X_AXIS] + X_PROBE_OFFSET_FROM_EXTRUDER,
               y_tmp = current_position[Y_AXIS] + Y_PROBE_OFFSET_FROM_EXTRUDER,
               z_tmp = current_position[Z_AXIS],
-              real_z = st_get_position_mm(Z_AXIS);  //get the real Z (since the auto bed leveling is already correcting the plane)
+              real_z = st_get_position_mm(Z_AXIS);  //get the real Z (since plan_get_position is now correcting the plane)
 
         apply_rotation_xyz(plan_bed_level_matrix, x_tmp, y_tmp, z_tmp); // Apply the correction sending the probe offset
-        //line below controls z probe offset, zprobe_zoffset is the actual offset that can be modified via m851 or is read from EEPROM
-        current_position[Z_AXIS] = z_tmp - real_z - zprobe_zoffset; // The difference is added to current position and sent to planner.
+
+        // Get the current Z position and send it to the planner.
+        //
+        // >> (z_tmp - real_z) : The rotated current Z minus the uncorrected Z (most recent plan_set_position/sync_plan_position)
+        //
+        // >> zprobe_zoffset : Z distance from nozzle to probe (set by default, M851, EEPROM, or Menu)
+        //
+        // >> Z_RAISE_AFTER_PROBING : The distance the probe will have lifted after the last probe
+        //
+        // >> Should home_offset[Z_AXIS] be included?
+        //
+        //      Discussion: home_offset[Z_AXIS] was applied in G28 to set the starting Z.
+        //      If Z is not tweaked in G29 -and- the Z probe in G29 is not actually "homing" Z...
+        //      then perhaps it should not be included here. The purpose of home_offset[] is to
+        //      adjust for inaccurate endstops, not for reasonably accurate probes. If it were
+        //      added here, it could be seen as a compensating factor for the Z probe.
+        //
+        current_position[Z_AXIS] = -zprobe_zoffset + Z_RAISE_AFTER_PROBING + (z_tmp - real_z);
+        // current_position[Z_AXIS] += home_offset[Z_AXIS]; // The probe determines Z=0, not "Z home"
         sync_plan_position();
       }
     #endif // !DELTA
     void raise_z_for_servo() {
       float zpos = current_position[Z_AXIS], z_dest = Z_RAISE_BEFORE_HOMING;
       z_dest += axis_known_position[Z_AXIS] ? zprobe_zoffset : zpos;
-      if (zpos < z_dest)
-        do_blocking_move_to(current_position[X_AXIS], current_position[Y_AXIS], z_dest); // also updates current_position
+      if (zpos < z_dest) do_blocking_move_to_z(z_dest); // also updates current_position
     }
   #endif