Proposed feature: Set Home Offsets

Add an item to the LCD menu that applies the current axis position to
the “add_homeing” offset.

Marlin/language.h

@@ -155,6 +155,7 @@
 	#define MSG_AUTOSTART "Autostart"
 	#define MSG_DISABLE_STEPPERS "Disable steppers"
 	#define MSG_AUTO_HOME "Auto home"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Set origin"
 	#define MSG_PREHEAT_PLA "Preheat PLA"
 	#define MSG_PREHEAT_PLA0 "Preheat PLA 1"
@@ -279,6 +280,7 @@
 	#define MSG_AUTOSTART "Autostart"
 	#define MSG_DISABLE_STEPPERS "Wylacz silniki"
 	#define MSG_AUTO_HOME "Auto. poz. zerowa"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Ustaw punkt zero"
 	#define MSG_PREHEAT_PLA "Rozgrzej PLA"
 	#define MSG_PREHEAT_PLA0 "Rozgrzej PLA 1"
@@ -406,6 +408,7 @@
 	#define MSG_AUTOSTART "Demarrage auto"
 	#define MSG_DISABLE_STEPPERS "Arreter moteurs"
 	#define MSG_AUTO_HOME "Home auto."
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Regler origine"
 	#define MSG_PREHEAT_PLA " Prechauffage PLA"
 	#define MSG_PREHEAT_PLA0 "Prechauff. PLA 1"
@@ -534,6 +537,7 @@
 	#define MSG_AUTOSTART        "Autostart"
 	#define MSG_DISABLE_STEPPERS "Stepper abschalt."
 	#define MSG_AUTO_HOME        "Auto Nullpunkt"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN       "Setze Nullpunkt"
 	#define MSG_PREHEAT_PLA      "Vorwärmen PLA"
 	#define MSG_PREHEAT_PLA0     "Vorwärmen PLA 1"
@@ -661,6 +665,7 @@
 	#define MSG_AUTOSTART " Autostart"
 	#define MSG_DISABLE_STEPPERS "Apagar motores"
 	#define MSG_AUTO_HOME "Llevar al origen"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Establecer cero"
 	#define MSG_PREHEAT_PLA "Precalentar PLA"
 	#define MSG_PREHEAT_PLA0 "Precalentar PLA 1"
@@ -794,6 +799,7 @@
 	#define MSG_AUTOSTART						"Автостарт"
 	#define MSG_DISABLE_STEPPERS 				"Выкл. двигатели"
 	#define MSG_AUTO_HOME						"Парковка"
+	#define MSG_SET_HOME_OFFSETS				"Set home offsets"
 	#define MSG_SET_ORIGIN						"Запомнить ноль"
 	#define MSG_PREHEAT_PLA 					"Преднагрев PLA"
 	#define MSG_PREHEAT_PLA0					"Преднагрев PLA0"
@@ -919,6 +925,7 @@
 	#define MSG_AUTOSTART            "Autostart"
 	#define MSG_DISABLE_STEPPERS     "Disabilita Motori"
 	#define MSG_AUTO_HOME            "Auto Home"
+	#define MSG_SET_HOME_OFFSETS     "Set home offsets"
 	#define MSG_SET_ORIGIN           "Imposta Origine"
 	#define MSG_PREHEAT_PLA          "Preriscalda PLA"
 	#define MSG_PREHEAT_PLA0         "Preriscalda PLA 1"
@@ -1044,6 +1051,7 @@
 	#define MSG_AUTOSTART "Autostart"
 	#define MSG_DISABLE_STEPPERS " Apagar motores"
 	#define MSG_AUTO_HOME "Ir para origen"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Estabelecer orig."
 	#define MSG_PREHEAT_PLA "Pre-aquecer PLA"
 	#define MSG_PREHEAT_PLA0 " pre-aquecer PLA 1"
@@ -1176,6 +1184,7 @@
 	#define MSG_AUTOSTART "Automaatti"
 	#define MSG_DISABLE_STEPPERS "Vapauta moottorit"
 	#define MSG_AUTO_HOME "Aja referenssiin"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Aseta origo"
 	#define MSG_PREHEAT_PLA "Esilammita PLA"
 	#define MSG_PREHEAT_PLA0 "Esilammita PLA 1"
@@ -1299,6 +1308,7 @@
 	#define MSG_AUTOSTART " Autostart"
 	#define MSG_DISABLE_STEPPERS "Amortar motors"
 	#define MSG_AUTO_HOME "Levar a l'orichen"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Establir zero"
 	#define MSG_PREHEAT_PLA "Precalentar PLA"
 	#define MSG_PREHEAT_PLA0 "Precalentar PLA0"
@@ -1431,6 +1441,7 @@
 	#define MSG_AUTOSTART "Autostart"
 	#define MSG_DISABLE_STEPPERS "Motoren uit"
 	#define MSG_AUTO_HOME "Auto home"
+	#define MSG_SET_HOME_OFFSETS "Set home offsets"
 	#define MSG_SET_ORIGIN "Nulpunt instellen"
 	#define MSG_PREHEAT_PLA "PLA voorverwarmen"
 	#define MSG_PREHEAT_PLA0 "PLA voorverw. 0"

Marlin/ultralcd.cpp

@@ -307,6 +307,23 @@ static void lcd_autostart_sd()
 }
 #endif
 
+void lcd_set_home_offsets()
+{
+    for(int8_t i=0; i < NUM_AXIS; i++) {
+      if (i != E_AXIS) {
+        add_homeing[i] -= current_position[i];
+        current_position[i] = 0.0;
+      }
+    }
+    plan_set_position(0.0, 0.0, 0.0, current_position[E_AXIS]);
+
+    // Audio feedback
+    enquecommand_P(PSTR("M300 S659 P200"));
+    enquecommand_P(PSTR("M300 S698 P200"));
+    lcd_return_to_status();
+}
+
+
 #ifdef BABYSTEPPING
 static void lcd_babystep_x()
 {
@@ -566,6 +583,7 @@ static void lcd_prepare_menu()
 #endif
     MENU_ITEM(gcode, MSG_DISABLE_STEPPERS, PSTR("M84"));
     MENU_ITEM(gcode, MSG_AUTO_HOME, PSTR("G28"));
+    MENU_ITEM(function, MSG_SET_HOME_OFFSETS, lcd_set_home_offsets);
     //MENU_ITEM(gcode, MSG_SET_ORIGIN, PSTR("G92 X0 Y0 Z0"));
 #if TEMP_SENSOR_0 != 0
   #if TEMP_SENSOR_1 != 0 || TEMP_SENSOR_2 != 0 || TEMP_SENSOR_BED != 0