Goodluck / API Reference


Apply changes to position, rotation, and scale, and update the instance array to be used by the shader.

An entity will be processed only if it's marked as dirty by another system:

game.World.Signature[entity] |= Has.Dirty;

A fast path for entities without the SpatialNode2D component skips the computation of the World transformation matrix on the CPU. Instead, raw position, rotation, and scale are stored in the instance array, and the shader computes the transformation matrix from them. This is very fast and can be used effectively for particles and background tiles.

Entities with the SpatialNode2D component have their World transformation matrix computed in the system, i.e. on the CPU. The World matrices of their parents are taken into account. The data is stored in the instance array implicitly, taking advantage of the fact that the World property of the SpatialNode2D component is a view into the instance array buffer.

sys_transform2d doesn't depend on the order of entities in the world, but it works best when parents are added before children. This is the default insertion order of instantiate(), but because entities can be later recycled, it's not guaranteed.

sys_transform2d also updates the node's Parent field. When reparenting entities, it's not necessary to assign the new parent manually. OTOH, the Parent field should only be referenced after sys_transform2d has already run during the frame.