LinuxJoystick.h

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#ifndef  _GAMS_UTILITY_LINUXJOYSTICK_H
#define  _GAMS_UTILITY_LINUXJOYSTICK_H
 
#include <string>
#include <stdio.h>
#include "gams/loggers/GlobalLogger.h"
 
namespace gams { namespace utility {
 
class JoystickEvent
{
  public:
    uint32_t time;
    int16_t value;
    unsigned char type;
    unsigned char number;
};
 
class Joystick
{
  private:
 
  // handle to the device
  FILE * file_ = 0;
 
  public:
 
  inline bool close_handle(void)
  {
    if (file_ != 0)
    {
      madara_logger_ptr_log(gams::loggers::global_logger.get(),
        gams::loggers::LOG_MAJOR,
        "gams::utility::Joystick::open: " \
        "attempting close on existing file %x\n",
        file_);
 
      fclose(file_);
 
      // clean up just in case user calls close 2x
      file_ = 0;
 
      return true;
    }
    else
    {
      madara_logger_ptr_log(gams::loggers::global_logger.get(),
        gams::loggers::LOG_MAJOR,
        "gams::utility::Joystick::open: " \
        "file is unset\n");
    }
 
    return false;
  }
 
  inline bool open_handle(const std::string & handle)
  {
    madara_logger_ptr_log(gams::loggers::global_logger.get(),
      gams::loggers::LOG_MAJOR,
      "gams::utility::Joystick::open: " \
      "attempting close on file %x\n",
      file_);
 
    close_handle();
 
    madara_logger_ptr_log(gams::loggers::global_logger.get(),
      gams::loggers::LOG_MAJOR,
      "gams::utility::Joystick::open: " \
      "calling fopen on %s\n",
      handle.c_str());
 
    file_ = fopen(handle.c_str(), "rb");
 
    madara_logger_ptr_log(gams::loggers::global_logger.get(),
      gams::loggers::LOG_MAJOR,
      "gams::utility::Joystick::open: " \
      "return of fopen is %x\n",
      file_);
 
    return file_ != 0;
  }
 
  Joystick(const std::string & handle)
  : file_(0)
  {
    if(handle != "")
    {
      open_handle(handle);
    }
  }
 
  Joystick()
  : file_(0)
  {
 
  }
 
  ~Joystick()
  {
    close_handle();
  }
 
  inline bool get(JoystickEvent & event)
  {
    size_t events = 0;
 
    if (file_ != 0)
    {
      events = fread(&event, sizeof(event), 1, file_);
    }
 
    madara_logger_ptr_log(gams::loggers::global_logger.get(),
      gams::loggers::LOG_MAJOR,
      "gams::utility::Joystick::open: " \
      "fread returned %zu events\n",
      events);
 
    return events == 1;
  }
 
  inline bool is_axis(const JoystickEvent & event) const
  {
    // we don't want inits
    return (event.type & 0x02) != 0;
  }
 
  inline bool is_button(const JoystickEvent & event) const
  {
    // we don't want inits
    return (event.type & 0x01) != 0;
  }
 
  inline bool is_x_move(const JoystickEvent & event) const
  {
    return event.number == 0;
  }
 
  inline bool is_y_move(const JoystickEvent & event) const
  {
    return event.number == 1;
  }
 
  inline bool is_rotate(const JoystickEvent & event) const
  {
    return event.number == 3;
  }
 
  inline bool is_z_move(const JoystickEvent & event) const
  {
    return event.number == 4;
  }
 
  inline bool is_init(const JoystickEvent & event) const
  {
    return (event.type & 0x80) != 0;
  }
 
  inline double to_double(const JoystickEvent & event) const
  {
    double result = event.value;
    result /= 32768;
 
    // note that we're cheating here because positives go up to 32767
    // so, max positive axis will be 0.999969482
 
    return result;
  }
};
 
}}
 
#endif // _GAMS_UTILITY_LINUXJOYSTICK_H