ovision_client/overhead_vision_client.h

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#ifndef OVERHEAD_VISION_CLIENT_H_GAURD
#define OVERHEAD_VISION_CLIENT_H_GAURD

// ==========================================================================
// File name:  vision.c
// Author:  Troy K. Becicka - Derek King
// Description: 
//   The purpose of vision is to act as only as a vision packet client for the
//   overhead vision system.  The class accepts vision packets, parses and
//   saves the data.
//   ./vision --bt/--wlan <craftnum>
// NOTE:  If you get a connect error "too many links", just unplug the USB 
//        Bluetooth adapter and plug it back in.
// ==========================================================================

// ==========================================================================
// Directions for starting overhead vision system
//
// First start vision client on each vision machine
//  logon to vision machine as root (you might need to do this from tale):
//   ssh root@vision#.me.uiuc.edu
//  move to vision program directory:
//   cd /home/afulford/PROJECT/CURRENT_WORKING_VISION
//  run vision client:
//   ./client
// 
//+ Next start vision server on tale:
//   /home2/becicka/HoTDeC/bt_wlan_server_sbc/server/server 1234 --wlan
// ==========================================================================

#include "../trucknet/unp.h"
#include <math.h>
#include <queue>


// Packet types
//#define CONTROL_DATA 0
//#define VISION_DATA 1
//#define CRAFT2CRAFT 2
//#define MAX_NUM_HC 10
//#define PUCK_ID 10
//#define SEQ_NUM_ROLLOVER 20000
//#define ACL_DATA_HDR_SIZE 5    // header size of an HCI ACL data packet (Bluetooth)


enum hc_feedback_type {DISCONN_REQ, CHARGING_STATE, CONTROL_ACK};
typedef enum hc_feedback_type hc_fb_type;


typedef struct
{
   hc_fb_type type;
   int charging;  // 0 when craft is not charging
   unsigned int sbc_battery_voltage;
   unsigned int thruster_battery_voltage;
   unsigned short ctrl_ack_num;  // only used for feedback type CONTROL_ACK
} hc_feedback_t;



// Defines the header for control and vision packets sent from
// the server to the hovercraft
typedef struct 
{
   unsigned short int seq_number; 
   struct timeval timestamp;  
   unsigned int packet_size : 8; // total packet size in bytes (including header and payload)
   unsigned int packet_type : 3; // 000 for control, 001 for vision data, 010 for craft-to-craft messages
   unsigned int num_hc_included : 5;  // total number of craft for which vision data is included in the packet
} srv_pkt_header_t;

// Defines the structure for control and vision packets sent from 
// the server to the hovercraft
typedef struct
{
   srv_pkt_header_t header;
   unsigned short data[256];
} srv_packet_t;




class OverheadVisionClient
{
  protected:

        enum {CONTROL_DATA=0, VISION_DATA=1, CRAFT2CRAFT=2};
        
  public:

        OverheadVisionClient(int patternNumber = 0);
        virtual ~OverheadVisionClient(void);

        
        int nextPacket(void);
        inline int findMyPattern(void) {return findPattern(myPatternNumber);}
        int findPattern(int patternNumber);     
        int getIndex(int index); 
        
        virtual int recv(void) = 0;
        virtual int recvNoWait(void) = 0;

        inline int getSeqNum(void);
        inline int getCount(void);
        inline int getID(void);
        inline float getX(void);
        inline float getZ(void);
        inline float getAngle(void);
        
 protected:     

        int myPatternNumber;
        
        std::queue<srv_packet_t> packetQ;
        const srv_packet_t *currentPacket;
        const unsigned short *currentData;
        
        static const float toMeters = 1.0 / 10000.0;
        static const float toRadians = M_PI / 1800.0;

  private:              
        // Make sure defaults copy constructor and operator= aren't created,
        // they are not safe,  we need to duplicate or reference count the SOCKETS
        // we use to make them safe
        OverheadVisionClient(const OverheadVisionClient &o) {}
        const OverheadVisionClient& operator= (const OverheadVisionClient &o) {return *this;}           

};


inline int
OverheadVisionClient::getSeqNum(void) {
        assert(currentPacket != NULL);
        return currentPacket->header.seq_number;
}

inline int
OverheadVisionClient::getCount(void) {
        assert(currentPacket != NULL);
        return currentPacket->header.num_hc_included;
}

inline int
OverheadVisionClient::getID(void) {
        assert(currentData != NULL);
        return currentData[0]; 
}

inline float
OverheadVisionClient::getX(void) {
        assert(currentData != NULL);
        return ((float) currentData[1]) * toMeters;
}

inline float
OverheadVisionClient::getZ(void) {
        assert(currentData != NULL);
        return ((float) currentData[2]) * toMeters;
}

inline float
OverheadVisionClient::getAngle(void) {
        assert(currentData != NULL);
        return ((float) currentData[3]) * toRadians;
}



#endif

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