Decouple XYZ relative from E relative.

Firmware/Configuration_adv.h

@@ -152,7 +152,6 @@
 #define Z_HOME_RETRACT_MM 2
 //#define QUICK_HOME  //if this is defined, if both x and y are to be homed, a diagonal move will be performed initially.
 
-#define AXIS_RELATIVE_MODES {0, 0, 0, 0}
 #define MAX_STEP_FREQUENCY 40000 // Max step frequency for Ultimaker (5000 pps / half step). Toshiba steppers are 4x slower, but Prusa3D does not use those.
 //By default pololu step drivers require an active high signal. However, some high power drivers require an active low signal as step.
 #define INVERT_X_STEP_PIN 0

Firmware/Marlin.h

@@ -294,7 +294,7 @@ void setPwmFrequency(uint8_t pin, int val);
 
 extern bool fans_check_enabled;
 extern float homing_feedrate[];
-extern bool axis_relative_modes[];
+extern uint8_t axis_relative_modes;
 extern float feedrate;
 extern int feedmultiply;
 extern int extrudemultiply; // Sets extrude multiply factor (in percent) for all extruders

Firmware/Marlin_main.cpp

@@ -178,9 +178,7 @@ float default_retraction = DEFAULT_RETRACTION;
 
 
 float homing_feedrate[] = HOMING_FEEDRATE;
-// Currently only the extruder axis may be switched to a relative mode.
-// Other axes are always absolute or relative based on the common relative_mode flag.
-bool axis_relative_modes[] = AXIS_RELATIVE_MODES;
+uint8_t axis_relative_modes;
 int feedmultiply=100; //100->1 200->2
 int extrudemultiply=100; //100->1 200->2
 int extruder_multiply[EXTRUDERS] = {100
@@ -5367,21 +5365,19 @@ if(eSoundMode!=e_SOUND_MODE_SILENT)
 
     /*!
 	### G90 - Switch off relative mode <a href="https://reprap.org/wiki/G-code#G90:_Set_to_Absolute_Positioning">G90: Set to Absolute Positioning</a>
-	All coordinates from now on are absolute relative to the origin of the machine. E axis is also switched to absolute mode.
+	All coordinates from now on are absolute relative to the origin of the machine.
     */
     case 90: {
-        for(uint8_t i = 0; i != NUM_AXIS; ++i)
-            axis_relative_modes[i] = false;
+		axis_relative_modes &= ~(X_AXIS_MASK | Y_AXIS_MASK | Z_AXIS_MASK);
     }
     break;
 
     /*!
 	### G91 - Switch on relative mode <a href="https://reprap.org/wiki/G-code#G91:_Set_to_Relative_Positioning">G91: Set to Relative Positioning</a>
-    All coordinates from now on are relative to the last position. E axis is also switched to relative mode.
+    All coordinates from now on are relative to the last position.
 	*/
     case 91: {
-        for(uint8_t i = 0; i != NUM_AXIS; ++i)
-            axis_relative_modes[i] = true;
+		axis_relative_modes |= X_AXIS_MASK | Y_AXIS_MASK | Z_AXIS_MASK;
     }
     break;
 
@@ -6558,7 +6554,7 @@ Sigma_Exit:
 	Makes the extruder interpret extrusion as absolute positions.
     */
     case 82:
-      axis_relative_modes[E_AXIS] = false;
+      axis_relative_modes &= ~E_AXIS_MASK;
       break;
 
     /*!
@@ -6566,7 +6562,7 @@ Sigma_Exit:
 	Makes the extruder interpret extrusion values as relative positions.
     */
     case 83:
-      axis_relative_modes[E_AXIS] = true;
+      axis_relative_modes |= E_AXIS_MASK;
       break;
 
     /*!
@@ -9190,7 +9186,7 @@ void get_coordinates()
   for(int8_t i=0; i < NUM_AXIS; i++) {
     if(code_seen(axis_codes[i]))
     {
-      bool relative = axis_relative_modes[i];
+      bool relative = axis_relative_modes & (1 << i);
       destination[i] = (float)code_value();
       if (i == E_AXIS) {
         float emult = extruder_multiplier[active_extruder];
@@ -10589,7 +10585,7 @@ void uvlo_()
 
     // Store the print E position before we lose track
 	eeprom_update_float((float*)(EEPROM_UVLO_CURRENT_POSITION_E), current_position[E_AXIS]);
-	eeprom_update_byte((uint8_t*)EEPROM_UVLO_E_ABS, axis_relative_modes[3]?0:1);
+	eeprom_update_byte((uint8_t*)EEPROM_UVLO_E_ABS, (axis_relative_modes & E_AXIS_MASK)?0:1);
 
     // Clean the input command queue, inhibit serial processing using saved_printing
     cmdqueue_reset();
@@ -11178,7 +11174,7 @@ void stop_and_save_print_to_ram(float z_move, float e_move)
     saved_feedmultiply2 = feedmultiply; //save feedmultiply
 	saved_active_extruder = active_extruder; //save active_extruder
 	saved_extruder_temperature = degTargetHotend(active_extruder);
-	saved_extruder_relative_mode = axis_relative_modes[E_AXIS];
+	saved_extruder_relative_mode = axis_relative_modes & E_AXIS_MASK;
 	saved_fanSpeed = fanSpeed;
 	cmdqueue_reset(); //empty cmdqueue
 	card.sdprinting = false;
@@ -11260,7 +11256,7 @@ void restore_print_from_ram_and_continue(float e_move)
 		wait_for_heater(_millis(), saved_active_extruder);
 		heating_status = 2;
 	}
-	axis_relative_modes[E_AXIS] = saved_extruder_relative_mode;
+	axis_relative_modes ^= (-saved_extruder_relative_mode ^ axis_relative_modes) & E_AXIS_MASK;
 	float e = saved_pos[E_AXIS] - e_move;
 	plan_set_e_position(e);
   

Firmware/mmu.cpp

@@ -795,8 +795,8 @@ void mmu_load_to_nozzle()
 {
 	st_synchronize();
 	
-	bool saved_e_relative_mode = axis_relative_modes[E_AXIS];
-	if (!saved_e_relative_mode) axis_relative_modes[E_AXIS] = true;
+	const bool saved_e_relative_mode = axis_relative_modes & E_AXIS_MASK;
+	if (!saved_e_relative_mode) axis_relative_modes |= E_AXIS_MASK;
 	if (ir_sensor_detected)
 	{
 		current_position[E_AXIS] += 3.0f;
@@ -820,7 +820,7 @@ void mmu_load_to_nozzle()
 	feedrate = 871;
 	plan_buffer_line_curposXYZE(feedrate / 60, active_extruder);
     st_synchronize();
-	if (!saved_e_relative_mode) axis_relative_modes[E_AXIS] = false;
+	if (!saved_e_relative_mode) axis_relative_modes &= ~E_AXIS_MASK;
 }
 
 void mmu_M600_wait_and_beep() {

Firmware/ultralcd.cpp

@@ -7349,10 +7349,7 @@ void lcd_print_stop()
 
     planner_abort_hard(); //needs to be done since plan_buffer_line resets waiting_inside_plan_buffer_line_print_aborted to false. Also copies current to destination.
     
-    axis_relative_modes[X_AXIS] = false;
-    axis_relative_modes[Y_AXIS] = false;
-    axis_relative_modes[Z_AXIS] = false;
-    axis_relative_modes[E_AXIS] = true;
+    axis_relative_modes = E_AXIS_MASK; //XYZ absolute, E relative
     
     isPrintPaused = false; //clear isPrintPaused flag to allow starting next print after pause->stop scenario.
 }