USAGE_PROPERTIES structure (winuser.h)
Contains device properties (Human Interface Device (HID) global items that correspond to HID usages) for any type of HID input device.
Syntax
typedef struct tagUSAGE_PROPERTIES {
USHORT level;
USHORT page;
USHORT usage;
INT32 logicalMinimum;
INT32 logicalMaximum;
USHORT unit;
USHORT exponent;
BYTE count;
INT32 physicalMinimum;
INT32 physicalMaximum;
} USAGE_PROPERTIES, *PUSAGE_PROPERTIES;
Members
level
A usage-specific value for a range-based linear control (knob or dial), an on/off control (toggle switch), a momentary control (mouse button), a one-shot control (button that triggers a single event), or re-trigger control (button that triggers a repeating event).
page
The Usage Page ID, such as VR Controls Page (0x03) or Game Controls Page (0x05).
usage
The Usage ID associated with a Usage Page, such as Turn Right/Left (21) or Move Right/Left (24) for a Game Controls Page.
logicalMinimum
The smallest value that the control can report.
logicalMaximum
The largest value that the control can report.
unit
The standard of measure used to describe a control's physical value (after converting the logical value using the exponent value). The HID specification defines codes for the basic units of length, mass, time, temperature, current, and luminous intensity.
exponent
The value used to scale a logical value to a physical value.
count
The number of data items contained in the report.
physicalMinimum
The logicalMinimum expressed in physical units (converted by multiplying logicalMinimum by exponent).
physicalMaximum
The logicalMaximum expressed in physical units (converted by multiplying logicalMaximum by exponent).
Remarks
The HID working group publishes a set of documents that make up the HID Usage Tables (the dictionary that describes what HID devices are allowed to do). These HID Usage Tables contain a list with Usage descriptions. A Usage provides information to an application developer about the intended meaning and use of a particular item described in the Report Descriptor. For example, there is a Usage defined for the left button of a mouse. The Report Descriptor can define where in a report an application can find the current state of the mouse’s left button. The Usage Tables are broken up into several name spaces, called Usage Pages. Each Usage Page describes a set of related Usages to help organize the document. The combination of a Usage Page and Usage defines the Usage ID that uniquely identifies a specific Usage in the Usage Tables.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 10, version 1809 [desktop apps only] |
| Minimum supported server | Windows Server [desktop apps only] |
| Header | winuser.h |