Class that has everything pertaining to a 2D world.
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<description>
Class that has everything pertaining to a 2D world. A physics space, a visual scenario and a sound space. 2D nodes register their resources into the current 2D world.
Direct access to the world's physics 2D space state. Used for querying current and potential collisions. When using multi-threaded physics, access is limited to [code]_physics_process(delta)[/code] in the main thread.