Filament sensor cleanup

Marlin/src/feature/pause.cpp

     KEEPALIVE_STATE(PAUSED_FOR_USER);
     wait_for_user = true;    // LCD click or M108 will clear this
     #if ENABLED(HOST_PROMPT_SUPPORT)
-      const char tool = '0'
-        #if NUM_RUNOUT_SENSORS > 1
-          + active_extruder
-        #endif
-      ;
+      const char tool = '0' + TERN0(MULTI_FILAMENT_SENSOR, active_extruder);
       host_prompt_do(PROMPT_USER_CONTINUE, PSTR("Load Filament T"), tool, CONTINUE_STR);
     #endif
 

Marlin/src/feature/runout.cpp

   TERN_(EXTENSIBLE_UI, ExtUI::onFilamentRunout(ExtUI::getActiveTool()));
 
   #if EITHER(HOST_PROMPT_SUPPORT, HOST_ACTION_COMMANDS)
-    const char tool = '0'
-      #if NUM_RUNOUT_SENSORS > 1
-        + active_extruder
-      #endif
-    ;
+    const char tool = '0' + TERN0(MULTI_FILAMENT_SENSOR, active_extruder);
   #endif
 
   //action:out_of_filament

Marlin/src/feature/runout.h

                       change    = old_state ^ new_state;
         old_state = new_state;
 
-        #ifdef FILAMENT_RUNOUT_SENSOR_DEBUG
+        #if ENABLED(FILAMENT_RUNOUT_SENSOR_DEBUG)
           if (change) {
             SERIAL_ECHOPGM("Motion detected:");
             LOOP_L_N(e, NUM_RUNOUT_SENSORS)
     private:
       static inline bool poll_runout_state(const uint8_t extruder) {
         const uint8_t runout_states = poll_runout_states();
-        #if NUM_RUNOUT_SENSORS == 1
-          UNUSED(extruder);
-        #else
+        #if MULTI_FILAMENT_SENSOR
           if ( !TERN0(DUAL_X_CARRIAGE, idex_is_duplicating())
             && !TERN0(MULTI_NOZZLE_DUPLICATION, extruder_duplication_enabled)
           ) return TEST(runout_states, extruder); // A specific extruder ran out
+        #else
+          UNUSED(extruder);
         #endif
         return !!runout_states;                   // Any extruder ran out
       }
       static inline void run() {
         const bool out = poll_runout_state(active_extruder);
         if (!out) filament_present(active_extruder);
-        #ifdef FILAMENT_RUNOUT_SENSOR_DEBUG
+        #if ENABLED(FILAMENT_RUNOUT_SENSOR_DEBUG)
           static bool was_out = false;
           if (out != was_out) {
             was_out = out;
       }
 
       static inline void run() {
-        #ifdef FILAMENT_RUNOUT_SENSOR_DEBUG
+        #if ENABLED(FILAMENT_RUNOUT_SENSOR_DEBUG)
           static millis_t t = 0;
           const millis_t ms = millis();
           if (ELAPSED(ms, t)) {

Marlin/src/gcode/feature/pause/M600.cpp

     int8_t DXC_ext = target_extruder;
     if (!parser.seen('T')) {  // If no tool index is specified, M600 was (probably) sent in response to filament runout.
                               // In this case, for duplicating modes set DXC_ext to the extruder that ran out.
-      #if HAS_FILAMENT_SENSOR && NUM_RUNOUT_SENSORS > 1
+      #if MULTI_FILAMENT_SENSOR
         if (idex_is_duplicating())
           DXC_ext = (READ(FIL_RUNOUT2_PIN) == FIL_RUNOUT2_STATE) ? 1 : 0;
       #else

Marlin/src/inc/Conditionals_adv.h

 
 #if ENABLED(FILAMENT_RUNOUT_SENSOR)
   #define HAS_FILAMENT_SENSOR 1
+  #if NUM_RUNOUT_SENSORS > 1
+    #define MULTI_FILAMENT_SENSOR 1
+  #endif
   #ifdef FILAMENT_RUNOUT_DISTANCE_MM
     #define HAS_FILAMENT_RUNOUT_DISTANCE 1
   #endif

Marlin/src/lcd/extui/ui_api.cpp

     #endif
   }
 
-  extruder_t getActiveTool() {
-    switch (active_extruder) {
+  extruder_t getTool(const uint8_t extruder) {
+    switch (extruder) {
+      case 7:  return E7;
+      case 6:  return E6;
       case 5:  return E5;
       case 4:  return E4;
       case 3:  return E3;
     }
   }
 
+  extruder_t getActiveTool() { return getTool(active_extruder); }
+
   bool isMoving() { return planner.has_blocks_queued(); }
 
   bool canMove(const axis_t axis) {

Marlin/src/lcd/extui/ui_api.h

     void setAxisMaxJerk_mm_s(const float, const extruder_t);
   #endif
 
+  extruder_t getTool(const uint8_t extruder);
   extruder_t getActiveTool();
   void setActiveTool(const extruder_t, bool no_move);
 

Marlin/src/pins/ramps/pins_RAMPS_CREALITY.h

 #define MOSFET_D_PIN                           7
 
 #define FIL_RUNOUT_PIN                         2
-#if NUM_RUNOUT_SENSORS > 1
+#if NUM_RUNOUT_SENSORS >= 2
   #define FIL_RUNOUT2_PIN                     15  // Creality CR-X can use dual runout sensors
 #endif