uint8_t direction;

bool quit;

bool space;

bool jump;

bool digit1, digit2, digit3;

struct input_t input;

void (*init)();

void (*fini)();

void (*set_screen_size)(int w, int h, const char *caption, int scale, const char *filter, bool fullscreen);

void (*set_screen_palette)(const uint8_t *colors, int offset, int count, int depth);

void (*set_palette_amiga)(const uint16_t *colors, int offset);

void (*set_copper_bars)(const uint16_t *data);

void (*set_palette_color)(int i, const uint8_t *colors);

void (*fade_in_palette)();

void (*fade_out_palette)();

void (*copy_bitmap)(const uint8_t *p, int w, int h);

void (*update_screen)();

void (*shake_screen)(int dx, int dy);

void (*transition_screen)(enum sys_transition_e type, bool open);

void (*process_events)();

void (*sleep)(int duration);

uint32_t (*get_timestamp)();

void (*start_audio)(sys_audio_cb callback, void *param);

void (*stop_audio)();

void (*lock_audio)();

void (*unlock_audio)();

void (*render_load_sprites)(int spr_type, int count, const struct sys_rect_t *r, const uint8_t *data, int w, int h, uint8_t color_key, bool update_pal);

void (*render_unload_sprites)(int spr_type);

void (*render_add_sprite)(int spr_type, int frame, int x, int y, int xflip);

void (*render_clear_sprites)();

void (*render_set_sprites_clipping_rect)(int x, int y, int w, int h);

void (*print_log)(FILE *fp, const char *s);