NAME¶

SDL_hid_write - Write an Output report to a HID device.

HEADER FILE¶

Defined in SDL3/SDL_hidapi.h

SYNOPSIS¶

#include "SDL3/SDL.h"

int SDL_hid_write(SDL_hid_device *dev, const unsigned char *data, size_t length);

DESCRIPTION¶

The first byte of data must contain the Report ID. For devices which only support a single report, this must be set to 0x0. The remaining bytes contain the report data. Since the Report ID is mandatory, calls to

SDL_hid_write () will always contain one more byte than the report contains. For example, if a hid report is 16 bytes long, 17 bytes must be passed to SDL_hid_write (), the Report ID (or 0x0, for devices with a single report), followed by the report data (16 bytes). In this example, the length passed in would be 17.

SDL_hid_write () will send the data on the first OUT endpoint, if one exists. If it does not, it will send the data through the Control Endpoint (Endpoint 0).

FUNCTION PARAMETERS¶

dev

a device handle returned from SDL_hid_open ().

data

the data to send, including the report number as the first byte.

length

the length in bytes of the data to send.

RETURN VALUE¶

Returns the actual number of bytes written and -1 on on failure; call

SDL_GetError () for more information.

AVAILABILITY¶

This function is available since SDL 3.1.3.