Navigator: Leverage overlapping fields in logic to save RAM by makeing them overlap in memory as well

src/modules/navigator/navigation.h

@@ -100,26 +100,34 @@ enum ORIGIN {
  */
 #pragma pack(push, 1)
 struct mission_item_s {
-	bool altitude_is_relative;	/**< true if altitude is relative from start point	*/
 	double lat;			/**< latitude in degrees				*/
 	double lon;			/**< longitude in degrees				*/
-	float altitude;			/**< altitude in meters	(AMSL)			*/
-	float yaw;			/**< in radians NED -PI..+PI, NAN means don't change yaw		*/
-	float loiter_radius;		/**< loiter radius in meters, 0 for a VTOL to hover     */
-	int8_t loiter_direction;	/**< 1: positive / clockwise, -1, negative.		*/
-	bool loiter_exit_xtrack;	/**< exit xtrack location: 0 for center of loiter wp, 1 for exit location */
-	enum NAV_CMD nav_cmd;		/**< navigation command					*/
-	float acceptance_radius;	/**< default radius in which the mission is accepted as reached in meters */
-	float time_inside;		/**< time that the MAV should stay inside the radius before advancing in seconds */
-	float pitch_min;		/**< minimal pitch angle for fixed wing takeoff waypoints */
-	bool autocontinue;		/**< true if next waypoint should follow after this one */
-	unsigned origin;		/**< where the waypoint has been generated		*/
-	int do_jump_mission_index;	/**< index where the do jump will go to                 */
-	unsigned do_jump_repeat_count;	/**< how many times do jump needs to be done            */
-	unsigned do_jump_current_count;	/**< count how many times the jump has been done	*/
-	float params[7];		/**< array to store mission command values for MAV_FRAME_MISSION ***/
-	int8_t frame;			/**< mission frame ***/
-	bool force_heading;		/**< heading needs to be reached ***/
+	union {
+		struct {
+			union {
+				float time_inside;		/**< time that the MAV should stay inside the radius before advancing in seconds */
+				float pitch_min;		/**< minimal pitch angle for fixed wing takeoff waypoints */
+			};
+			float acceptance_radius;	/**< default radius in which the mission is accepted as reached in meters */
+			float loiter_radius;		/**< loiter radius in meters, 0 for a VTOL to hover     */
+			float yaw;					/**< in radians NED -PI..+PI, NAN means don't change yaw		*/
+			float ___lat_float;			/**< padding */
+			float ___lon_float;			/**< padding */
+			float altitude;				/**< altitude in meters	(AMSL)			*/
+		};
+		float params[7];				/**< array to store mission command values for MAV_FRAME_MISSION ***/
+	};
+	enum NAV_CMD nav_cmd;				/**< navigation command					*/
+	int16_t do_jump_mission_index;		/**< index where the do jump will go to                 */
+	uint16_t do_jump_repeat_count;		/**< how many times do jump needs to be done            */
+	uint16_t do_jump_current_count;		/**< count how many times the jump has been done	*/
+	uint16_t origin;					/**< where the waypoint has been generated		*/
+	bool loiter_exit_xtrack;			/**< exit xtrack location: 0 for center of loiter wp, 1 for exit location */
+	bool force_heading;					/**< heading needs to be reached ***/
+	bool altitude_is_relative;			/**< true if altitude is relative from start point	*/
+	bool autocontinue;					/**< true if next waypoint should follow after this one */
+	int8_t frame;						/**< mission frame ***/
+	int8_t loiter_direction;			/**< 1: positive / clockwise, -1, negative.		*/
 };
 #pragma pack(pop)
 #include <uORB/topics/mission.h>