devela::_dep::sdl3::sys::hidapi

Function SDL_hid_write

pub unsafe extern "C" fn SDL_hid_write(
    dev: *mut SDL_hid_device,
    data: *const u8,
    length: usize,
) -> i32
Available on crate feature dep_sdl3 only.
Expand description

Write an Output report to a HID device.

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).

§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 3.2.0.