Support for multiple filament runout sensors

Marlin/src/feature/runout.h

@@ -27,8 +27,55 @@
 #ifndef _RUNOUT_H_
 #define _RUNOUT_H_
 
-extern bool filament_ran_out;
+#include "../sd/cardreader.h"
+#include "../module/printcounter.h"
+#include "../module/stepper.h"
+#include "../gcode/queue.h"
 
-void handle_filament_runout();
+#include "../inc/MarlinConfig.h"
+
+class FilamentRunoutSensor {
+
+  FilamentRunoutSensor() {}
+
+  static bool filament_ran_out;
+  static void setup();
+
+  FORCE_INLINE static reset() { filament_ran_out = false; }
+
+  FORCE_INLINE static bool check() {
+    #if NUM_RUNOUT_SENSORS < 2
+      // A single sensor applying to all extruders
+      return READ(FIL_RUNOUT_PIN) == FIL_RUNOUT_INVERTING;
+    #else
+      // Read the sensor for the active extruder
+      switch (active_extruder) {
+        case 0: return READ(FIL_RUNOUT_PIN) == FIL_RUNOUT_INVERTING;
+        case 1: return READ(FIL_RUNOUT2_PIN) == FIL_RUNOUT_INVERTING;
+        #if NUM_RUNOUT_SENSORS > 2
+          case 2: return READ(FIL_RUNOUT3_PIN) == FIL_RUNOUT_INVERTING;
+          #if NUM_RUNOUT_SENSORS > 3
+            case 3: return READ(FIL_RUNOUT4_PIN) == FIL_RUNOUT_INVERTING;
+            #if NUM_RUNOUT_SENSORS > 4
+              case 4: return READ(FIL_RUNOUT5_PIN) == FIL_RUNOUT_INVERTING;
+            #endif
+          #endif
+        #endif
+      }
+    #endif
+    return false;
+  }
+
+  FORCE_INLINE static void run() {
+    if ((IS_SD_PRINTING || print_job_timer.isRunning()) && check() && !filament_ran_out) {
+      filament_ran_out = true;
+      enqueue_and_echo_commands_P(PSTR(FILAMENT_RUNOUT_SCRIPT));
+      stepper.synchronize();
+    }
+  }
+
+};
+
+extern FilamentRunoutSensor runout;
 
 #endif // _RUNOUT_H_