diff options
Diffstat (limited to 'src/eetg.h')
| -rw-r--r-- | src/eetg.h | 146 |
1 files changed, 146 insertions, 0 deletions
@@ -44,6 +44,14 @@ struct eetg_object; typedef void (*eetg_write_fn)(const void *buffer, size_t size, void *arg); +/* + * Type for collision handling functions. + * + * Return true if the given objects collide. + * + * This function may not call any other function that could trigger + * another collision. + */ typedef bool (*eetg_handle_collision_fn)(struct eetg_object *object1, struct eetg_object *object2, int x, int y, void *arg); @@ -78,6 +86,12 @@ struct eetg_view { struct eetg_view_row rows[EETG_ROWS]; }; +/* + * World. + * + * A world contains layers, to which objects are added. When rendering + * a world, lower layers are processed before higher layers. + */ struct eetg_world { eetg_write_fn write_fn; void *write_fn_arg; @@ -93,37 +107,169 @@ struct eetg_world { bool handling_collision; }; +/* + * Initialize a world. + */ void eetg_world_init(struct eetg_world *world, eetg_write_fn write_fn, void *arg); + +/* + * Clear a world of all its objects. + * + * On return, all objects added to the world on entry are removed from + * the world. + */ void eetg_world_clear(struct eetg_world *world); + +/* + * Set the collision handling function of a world. + * + * The passed function may be NULL. + */ void eetg_world_set_collision_fn(struct eetg_world *world, eetg_handle_collision_fn handle_collision_fn, void *arg); + +/* + * Add an object to a world. + * + * The object must not already be part of another world. + * + * The object may be placed partially or completely outside the visible + * part of the world. + * + * After the addition, the world is scanned for collisions. If the addition + * triggered a collision, it is cancelled. + * + * This function returns true if a collision occurred, false otherwise. + */ bool eetg_world_add(struct eetg_world *world, struct eetg_object *object, int x, int y, int layer_id); + +/* + * Look up an object in a world at the given coordinates. + * + * If the layer ID is valid, look up only in layers greater than or equal to + * the given ID. Otherwise, look up in the entire world. + */ struct eetg_object *eetg_world_lookup(struct eetg_world *world, int x, int y, int layer_id); + +/* + * Remove an object from a world. + */ void eetg_world_remove(struct eetg_world *world, struct eetg_object *object); + +/* + * Render a world. + * + * If sync is true, the entire screen is written out. Otherwise, only update + * the screen. + */ void eetg_world_render(struct eetg_world *world, bool sync); +/* + * Initialize an object. + * + * The sprite must be a null-terminated string. Its content must form a + * rectangle, i.e. all lines must have the exact same length. + * + * On return, the object is not part of a world, its coordinates are 0,0 + * and its layer ID is invalid. + */ void eetg_object_init(struct eetg_object *object, int type, const char *sprite); + +/* + * Set the color of an object. + */ void eetg_object_set_color(struct eetg_object *object, int color); + +/* + * Get the type of an object. + */ int eetg_object_get_type(const struct eetg_object *object); + +/* + * Get the sprite of an object. + */ const char *eetg_object_get_sprite(const struct eetg_object *object); + +/* + * Get the coordinates of an object. + */ int eetg_object_get_x(const struct eetg_object *object); int eetg_object_get_y(const struct eetg_object *object); + +/* + * Get the dimensions of an object. + */ int eetg_object_get_width(const struct eetg_object *object); int eetg_object_get_height(const struct eetg_object *object); + +/* + * Check if an object is empty. + * + * An object is empty when the only characters of its sprite, except for + * new line characters, are space (' ') characters. + */ bool eetg_object_is_empty(const struct eetg_object *object); + +/* + * Move an object. + * + * If the object is part of a world, after the move, that world is scanned + * for collisions. If the move triggered a collision, it is cancelled. + * + * This function returns true if a collision occurred, false otherwise. + */ bool eetg_object_move(struct eetg_object *object, int x, int y); + +/* + * Update an object. + * + * This function must be called after modifying the sprite of an object. The + * content of the sprite when calling this function must form a rectangle, + * i.e. all lines must have the exact same length. + * + * If the object is part of a world, after the update, that world is scanned + * for collisions. If the update triggered a collision, it is cancelled. + * + * This function returns true if a collision occurred, false otherwise. + */ bool eetg_object_update(struct eetg_object *object); + +/* + * Get the cell of an object at the given coordinates. + * + * A cell is an index in the object sprite referring the to the given + * coordinates + * + * The given coordinates are world coordinates, i.e. the object coordinates + * are subtracted from the given coordinates. + */ int eetg_object_get_cell(const struct eetg_object *object, int x, int y); + +/* + * Get the world of an object. + */ struct eetg_world *eetg_object_get_world(const struct eetg_object *object); +/* + * Check if any of the given objects has the given type. + */ bool eetg_object_has_type(const struct eetg_object *object1, const struct eetg_object *object2, int type); +/* + * Initialize the pseudo-random number generator. + */ void eetg_init_rand(unsigned int seed); + +/* + * Generate a random number. + * + * See EETG_RAND_MAX. + */ int eetg_rand(void); #endif /* EETG_H */ |