Function heif_context_encode_grid 

pub unsafe extern "C" fn heif_context_encode_grid(
    ctx: *mut heif_context,
    tiles: *mut *mut heif_image,
    rows: u16,
    columns: u16,
    encoder: *mut heif_encoder,
    input_options: *const heif_encoding_options,
    out_image_handle: *mut *mut heif_image_handle,
) -> heif_error

@brief Encodes an array of images into a grid.

@param ctx The file context @param tiles User allocated array of images that will form the grid. @param rows The number of rows in the grid. @param columns The number of columns in the grid. @param encoder Defines the encoder to use. See heif_context_get_encoder_for_format() @param input_options Optional, may be nullptr. @param out_image_handle Returns a handle to the grid. The caller is responsible for freeing it. @return Returns an error if ctx, tiles, or encoder is nullptr. If rows or columns is 0.