#include enum position { POS_UNSET = -1, POS_LEFT = 0, POS_CENTRE = 1, POS_RIGHT = 2, POS_TOP = 0 << 4, POS_MIDDLE = 1 << 4, POS_BOTTOM = 2 << 4, POS_TOP_LEFT = POS_TOP | POS_LEFT, POS_TOP_CENTRE = POS_TOP | POS_CENTRE, POS_TOP_RIGHT = POS_TOP | POS_RIGHT, POS_MIDDLE_LEFT = POS_MIDDLE | POS_LEFT, POS_MIDDLE_CENTRE = POS_MIDDLE | POS_CENTRE, POS_MIDDLE_RIGHT = POS_MIDDLE | POS_RIGHT, POS_BOTTOM_LEFT = POS_BOTTOM | POS_LEFT, POS_BOTTOM_CENTRE = POS_BOTTOM | POS_CENTRE, POS_BOTTOM_RIGHT = POS_BOTTOM | POS_RIGHT, }; struct overlay { cairo_surface_t *surface; void (*show)(struct overlay *); void (*position)(struct overlay *, enum position); void (*hide)(struct overlay *); }; extern const cairo_user_data_key_t overlay_key; cairo_surface_t *x11_overlay_create(enum position pos, int max_width, int max_height); void x11_overlay_stop(void);