IDs: Introduce ID handling functions and data

IDs will be needed by multiple subsystems, so introduce the needed
variables and handling functions.

src/IDs.cpp

@@ -0,0 +1,45 @@
+//
+// Created by Teo-CD on 19/10/23.
+//
+
+#include "IDs.h"
+
+/* IDs are greater than one, offset the array to make it easier to use. */
+constexpr char promoDirs[][dirStrSize] = {
+		"INVALIDE",
+		"RANDONNEE",
+		"RESTO",
+		"AUTOBUS",
+		"MAYO",
+		"MADO",
+		"COOP",
+		"OURS",
+		"BAGAR",
+		"INCAPABLE",
+		"MYSTERE"
+};
+constexpr char charDirs[][dirStrSize] = {
+		"INVALIDE",
+		"GUILLAUME",
+		"MICHEL"
+};
+
+bool isIdGone(int8_t ID) {
+	return ID & idMaskGone;
+}
+
+bool isIdCharacter(int8_t ID) {
+	return ID & idMaskChar;
+}
+
+uint8_t getRawId(int8_t ID) {
+	return ID & ~(idMaskGone | idMaskChar);
+}
+
+bool isValidId(int8_t ID) {
+	uint8_t rawId = getRawId(ID);
+	if (isIdCharacter(ID))
+		return rawId < sizeof(charDirs) / dirStrSize;
+	else
+		return rawId < sizeof(promoDirs) / dirStrSize;
+}

src/RFID.cpp

@@ -39,7 +39,7 @@ int8_t RFID::checkTags() {
 				removeActiveTag(node, previousNode);
 				// Return the ID with the sign bit set to signal it has gone.
 				// If other tags are gone we can check on the next loop.
-				return node->tag_ID | 1<<7;
+				return node->tag_ID | idMaskGone;
 			}
 		}
 	}

src/main.cpp

@@ -2,8 +2,8 @@
 
 #include "Pinout.h"
 
-#include "RFID.h"
 #include "Com.h"
+#include "RFID.h"
 
 __attribute__((noreturn)) int main() {
 	pinMode(pin_DBG_LED_1, OUTPUT);