in src/libguac/protocol.c [513:539]
int guac_protocol_send_curve(guac_socket* socket, const guac_layer* layer,
int cp1x, int cp1y, int cp2x, int cp2y, int x, int y) {
int ret_val;
guac_socket_instruction_begin(socket);
ret_val =
guac_socket_write_string(socket, "5.curve,")
|| __guac_socket_write_length_int(socket, layer->index)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, cp1x)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, cp1y)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, cp2x)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, cp2y)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, x)
|| guac_socket_write_string(socket, ",")
|| __guac_socket_write_length_int(socket, y)
|| guac_socket_write_string(socket, ";");
guac_socket_instruction_end(socket);
return ret_val;
}