#define MAX_OBJECTS_PER_SCENE 30
#define MAX_SCRIPTS_PER_SCENE 30
#define MAX_STACKED_SCENES 5

struct object {
	int id; // 0 if slot unused
	int x;
	int y;
	int width;
	int height;
	const char *pixels;
	const struct level_clickregion *clickregion; // if not null, overrides click bounds check
};

typedef void (*script_wake_fn)(struct script *scr, int wakeupMode, int arg1, int arg2, int arg3, int arg4);
#define SCRIPT_HEADER \
	int id /* 0 if slot unused */; \
	int wakeupMode; \
	script_wake_fn wakeupFn; \
	int wakeupArg1; /* for SCRIPT_WAKEUP_OTHER_SCRIPT */
struct script {
	SCRIPT_HEADER
	int vars[100];
};

typedef void (*scene_render_fn)(struct scene *s);
void standard_scene_render(struct scene *s);
extern struct scene {
	int id;
	struct object objects[MAX_OBJECTS_PER_SCENE];
	struct script scripts[MAX_SCRIPTS_PER_SCENE];
	scene_render_fn render_fn;
	struct navmesh *navmesh; // defaults to non-null pointer to empty navmesh
} scenes[MAX_STACKED_SCENES];
extern int scene_depth; // number of stacked scenes
#define top_scene scenes[scene_depth-1]


struct script_player_walk {
	SCRIPT_HEADER
	int targetX;
	int targetY;
	int targetNavmeshTri;
	int currentNavmeshTri;
};

#define SCRIPT_WAKEUP_VIDEO_FRAME 1
#define SCRIPT_WAKEUP_OTHER_SCRIPT 2
#define SCRIPT_WAKEUP_OTHER_SCRIPT_INTERRUPTED 3 // Delivered to script that registers for SCRIPT_WAKEUP_OTHER_SCRIPT if that script is interrupted instead of completing.


// engine
// Scene changes - even push - may discard remaining events for the scene.
void push_scene(int scene);
void replace_scene(int scene);
void pop_scene();
void scene_add_clickrect(int id, int x, int y, int width, int height);
struct object *scene_add_object(int id, int x, int y, int width, int height, const char *pixels);
void scene_load_predef(const struct level_predef_data *predef);
struct object *find_object_by_id(int id);
struct script *scene_add_script(int id, bool interrupt_existing);
struct script *scene_get_script(int id);
bool deliver_script_wakeup(int wakeupMode, int wakeupArg1, int wakeupType, int arg1, int arg2, int arg3, int arg4); // deliver to scripts with given wakeupMode and wakeupArg1. Returns true if scene changed.
void start_player_walk_to_point(int x, int y); // x and y are not corrected to lie within navmesh

// game-specific constants
#define SCENE_LOBBY 1
#define SCENE_MANAGERS_OFFICE 2
#define SCENE_MANAGERS_OFFICE_SAFE 3
#define SCENE_BASEMENT 4

// game.cpp
void scene_setup(int scene, int fromscene);
void onclick(int curscene, int objid);