Power Loss Recovery for volumetric extrusion (#15734)

Marlin/src/feature/power_loss_recovery.cpp

       info.active_extruder = active_extruder;
     #endif
 
+    #if DISABLED(NO_VOLUMETRICS)
+      info.volumetric_enabled = parser.volumetric_enabled;
+      #if EXTRUDERS > 1
+        for (int8_t e = 0; e < EXTRUDERS; e++) info.filament_size[e] = planner.filament_size[e];
+      #else
+        if (parser.volumetric_enabled) info.filament_size = planner.filament_size[active_extruder]; 
+      #endif    
+    #endif
+
     #if EXTRUDERS
       HOTEND_LOOP() info.target_temperature[e] = thermalManager.temp_hotend[e].target;
     #endif
     gcode.process_subcommands_now(cmd);
   #endif
 
+  // Recover volumetric extrusion state
+  #if DISABLED(NO_VOLUMETRICS)    
+    #if EXTRUDERS > 1
+      for (int8_t e = 0; e < EXTRUDERS; e++) {
+        dtostrf(info.filament_size[e], 1, 3, str_1);
+        sprintf_P(cmd, PSTR("M200 T%i D%s"), e, str_1);
+        gcode.process_subcommands_now(cmd);
+      }
+      if (!info.volumetric_enabled) {
+        sprintf_P(cmd, PSTR("M200 T%i D0"), info.active_extruder);
+        gcode.process_subcommands_now(cmd);
+      }
+    #else
+      if (info.volumetric_enabled) {
+        dtostrf(info.filament_size, 1, 3, str_1);
+        sprintf_P(cmd, PSTR("M200 D%s"), str_1);
+        gcode.process_subcommands_now(cmd);
+      }
+    #endif
+  #endif
+
   #if HAS_HEATED_BED
     const int16_t bt = info.target_temperature_bed;
     if (bt) {

Marlin/src/feature/power_loss_recovery.h

     uint8_t active_extruder;
   #endif
 
+  #if DISABLED(NO_VOLUMETRICS)
+    bool volumetric_enabled;
+    #if EXTRUDERS > 1
+      float filament_size[EXTRUDERS]; 
+    #else
+      float filament_size; 
+    #endif    
+  #endif
+
   #if HOTENDS
     int16_t target_temperature[HOTENDS];
   #endif