SYNOPSIS

#include <ggi/events.h>
typedef struct gii_valrange {
int32_t min, center, max;
} gii_valrange;
typedef struct {
uint32_t number;
char longname[75];
char shortname[5];
gii_valrange range;
gii_phystype phystype;
int32_t SI_add,SI_mul,SI_div,SI_shift;
} gii_cmddata_getvalinfo;

DESCRIPTION

This structure is used to describe the values reported by a specific valuator.

STRUCTURE MEMBERS

gii_cmddata_getvalinfo fields are defined as follow:

number

Number of the queried valuator.

longname

A human-redable NULL terminated string identifying the valuator.

shortname

A NULL terminated abbreviated name for this valuator.

range

Contains the minimum, center and maximum values for this valuator. Note that this range may change on some devices due to calibration, but it is usually not expected that a device recalibrates while in use. You should react gracefully to values received from the valuator that are outside the specified range, though.

phystype

Gives the physical quantity the device measures. The idea is to report the thing the user actually controls. I.e. a Joystick actually measures resistance, but should report GII_PT_ANGLE or GII_PT_FORCE, as that is what the user does to the stick and what results in the changed resistance.

SI_add, SI_mul, SI_div, SI_shift

Using these values, it is possible to give calibration data to the application or to compute the actual floating point value (in the unit expressed in phystype) reported by the valuator with the following formula:

(float)(SI_add + value) * (float)SI_mul / (float)SI_div * pow(2.0, SI_shift);

PHYSICAL UNITS

The following physical units are defined for gii_phystype:

• GII_PT_UNKNOWN : unknown
• GII_PT_TIME : base unit s (second)
• GII_PT_FREQUENCY : base unit 1/s (Hz)
• GII_PT_LENGTH : base unit m (meter)
• GII_PT_VELOCITY : base unit m/s
• GII_PT_ACCELERATION : base unit m/s^2
• GII_PT_ANGLE : base unit radian
• GII_PT_ANGVELOCITY : base unit radian/s
• GII_PT_ANGACCELERATION : base unit radian/s^2
• GII_PT_AREA : base unit m^2
• GII_PT_VOLUME : base unit m^3
• GII_PT_MASS : base unit kg
• GII_PT_FORCE : base unit N (kg*m/s^2)
• GII_PT_PRESSURE : base unit N/m^2 (Pa)
• GII_PT_TORQUE : base unit Nm
• GII_PT_ENERGY : base unit Nm, VAs, J
• GII_PT_POWER : base unit Nm/s, VA, W
• GII_PT_TEMPERATURE : base unit K
• GII_PT_CURRENT : base unit A
• GII_PT_VOLTAGE : base unit V (kg*m^2/(As^3))
• GII_PT_RESISTANCE : base unit V/A (Ohm)
• GII_PT_CAPACITY : base unit As/V (Farad)
• GII_PT_INDUCTIVITY : base unit Vs/A (Henry)