text: #ifndef BACKEND_HEADLESS_H
  #define BACKEND_HEADLESS_H
  
  #include <wlr/backend/headless.h>
  #include <wlr/backend/interface.h>
  
  #define HEADLESS_DEFAULT_REFRESH (60 * 1000) // 60 Hz
  
  struct wlr_headless_backend {
  	struct wlr_backend backend;
  	struct wlr_egl egl;
  	struct wlr_renderer *renderer;
  	struct wl_display *display;
  	struct wl_list outputs;
  	struct wl_list input_devices;
  	struct wl_listener display_destroy;
  	bool started;
  };
  
  struct wlr_headless_output {
  	struct wlr_output wlr_output;
  
  	struct wlr_headless_backend *backend;
  	struct wl_list link;
  
  	void *egl_surface;
  	struct wl_event_source *frame_timer;
  	int frame_delay; // ms
  };
  
  struct wlr_headless_input_device {
  	struct wlr_input_device wlr_input_device;
  
  	struct wlr_headless_backend *backend;
  };
  
  struct wlr_headless_backend *headless_backend_from_backend(
  	struct wlr_backend *wlr_backend);
  
  #endif
  