AP_Mission: Added immediate trigger for DO_SET_CAM_TRIGG_DIST

libraries/AP_Mission/AP_Mission.cpp

@@ -941,6 +941,7 @@ MAV_MISSION_RESULT AP_Mission::mavlink_int_to_mission_cmd(const mavlink_mission_
 
     case MAV_CMD_DO_SET_CAM_TRIGG_DIST:                 // MAV ID: 206
         cmd.content.cam_trigg_dist.meters = packet.param1;  // distance between camera shots in meters
+        cmd.content.cam_trigg_dist.trigger = packet.param3; // when enabled, camera triggers once immediately
         break;
 
     case MAV_CMD_DO_FENCE_ENABLE:                       // MAV ID: 207
@@ -1380,6 +1381,7 @@ bool AP_Mission::mission_cmd_to_mavlink_int(const AP_Mission::Mission_Command& c
 
     case MAV_CMD_DO_SET_CAM_TRIGG_DIST:                 // MAV ID: 206
         packet.param1 = cmd.content.cam_trigg_dist.meters;  // distance between camera shots in meters
+        packet.param3 = cmd.content.cam_trigg_dist.trigger; // when enabled, camera triggers once immediately
         break;
 
     case MAV_CMD_DO_FENCE_ENABLE:                       // MAV ID: 207

libraries/AP_Mission/AP_Mission.h

@@ -137,6 +137,7 @@ public:
     // set cam trigger distance command structure
     struct PACKED Cam_Trigg_Distance {
         float meters;           // distance
+        uint8_t trigger;        // triggers one image capture immediately 
     };
 
     // gripper command structure

libraries/AP_Mission/AP_Mission_Commands.cpp

@@ -102,6 +102,9 @@ bool AP_Mission::start_command_camera(const AP_Mission::Mission_Command& cmd)
 
     case MAV_CMD_DO_SET_CAM_TRIGG_DIST:
         camera->set_trigger_distance(cmd.content.cam_trigg_dist.meters);
+        if (cmd.content.cam_trigg_dist.trigger == 1) {
+            camera->take_picture();
+        }
         return true;
 
     default: