Copter: Change autopilot modes into Enum

ArduCopter/defines.h

@@ -92,26 +92,25 @@ enum aux_sw_func {
 #define HIL_MODE_DISABLED               0
 #define HIL_MODE_SENSORS                1
 
-// Auto Pilot modes
-// ----------------
-#define STABILIZE 0                     // hold level position
-#define ACRO 1                          // rate control
-#define ALT_HOLD 2                      // AUTO control
-#define AUTO 3                          // AUTO control
-#define GUIDED 4                        // AUTO control
-#define LOITER 5                        // Hold a single location
-#define RTL 6                           // AUTO control
-#define CIRCLE 7                        // AUTO control
-#define LAND 9                          // AUTO control
-#define OF_LOITER 10                    // Hold a single location using optical flow sensor
-#define DRIFT 11                        // DRIFT mode (Note: 12 is no longer used)
-#define SPORT 13                        // earth frame rate control
-#define FLIP        14                  // flip the vehicle on the roll axis
-#define AUTOTUNE    15                  // autotune the vehicle's roll and pitch gains
-#define POSHOLD     16                  // position hold with manual override
-#define STOP        17                  // Full-Stop using inertial/GPS system, no pilot input
-#define NUM_MODES   18  
-
+// Auto Pilot Modes enumeration
+enum autopilot_modes {
+    STABILIZE =     0,  // 0, manual airframe angle with manual throttle
+    ACRO,               // 1, manual body-frame angular rate with manual throttle
+    ALT_HOLD,           // 2, manual airframe angle with automatic throttle
+    AUTO,               // 3, fully automatic waypoint control
+    GUIDED,             // 4, fully automatic fly to coordinate or fly at velocity/direction
+    LOITER,             // 5, automatic horizontal acceleration with automatic throttle
+    RTL,                // 6, automatic return to launching point
+    CIRCLE,             // 7, automatic circular flight with automatic throttle
+    LAND =          9,  // 9, automatic landing with horizontal position control
+    OF_LOITER,          // 10, automatic position control using optical flow sensor
+    DRIFT,              // 11, semi-automatic position, yaw and throttle control
+    SPORT =        13,  // 13, manual earth-frame angular rate control with manual throttle
+    FLIP,               // 14, automatically flip the vehicle on the roll axis
+    AUTOTUNE,           // 15, automatically tune the vehicle's roll and pitch gains
+    POSHOLD,            // 16, automatic position hold with manual override, with automatic throttle
+    STOP                // 17, full-stop using inertial/GPS system, no pilot input
+};
 
 // Tuning enumeration
 enum tuning_func {