Getter Filtering

Filtering lets you pass in a custom function to some getter functions that decides whether an object should be included or not.

// Simple filter: return true only if obj is a deposit
static bool is_deposit(const t_obj *obj)
{
	return (obj->type == OBJ_DEPOSIT);
}
 
void example(void)
{
	t_pos pos = {5, 5}; // search around this position
 
	// Use the filter with the nearest-object getter
	t_obj *nearest = core_get_obj_filter_nearest(pos, is_deposit);
 
	if (nearest) printf("Nearest deposit at (%d,%d)\n", nearest->pos.x, nearest->pos.y);
}

func example(g *game.Game) {
	pos := game.Position{X: 5, Y: 5} // search around this position
 
	// Use an inline predicate with the nearest-object getter
	nearest := g.NearestObject(pos, func(obj *game.Object) bool {
		return obj.Type == game.ObjectDeposit
	})
 
	if nearest != nil {
		fmt.Printf("Nearest deposit at (%d,%d)\n", nearest.Pos.X, nearest.Pos.Y)
	}
}

• C: Here, is_deposit acts as the condition. The getter runs this check on every object in the game and returns the one closest to (5,5) that passes. This can be used with a large variety of different getter functions.
• Go: You pass predicate functions (closures) directly as arguments. The getter runs this check on every object in the game and returns the one closest to (5,5) that passes. This can be used with ObjectsFilter(), NearestObject(), and other getter methods.