Port to ECS

[vorg]

Log of outstanding issues and roadblocks

• [x] assumption that every entity has transform, entity was adding transform in it's constructor -> removed that assumption in line with ECS in Nodes
  • transform.enabled could enable/disable whole entity
• [x] in pex-renderer camera was updating it's own matrices, in nodes it's the ecs.Camera node via pex-cam, i we add "just data" camera in ecs, we need proper camera system?
• [x] it is assumed that all entities are children of root entity and entities array is rebuilt every frame by traversing transform tree -> removed, call renderer.add to push entities to an array, might remove that indirection in the future as well and access entities directly
• [x] how system can find other systems if systems is array of plain objects with update function. Do we need "type" property on them? Why not Classes then?
• [x] who is responsible for passing ctx to systems and when? -> currently done in renderer.createSystem
• [x] default component properties are exploited quite a lot e.g. in renderer cullFace: material.cullFaceMode assumes that cullFaceMode is well defined

Open Questions

• [x] factory functions vs objects
• [x] system naming systems/geometry-system ugh

[vorg]

The tags and parent params were switched in createEntity factory function

return createEntity(components, tags, this);
export default function createEntity(components, parent, tags) {
constructor(components, tags, renderer) {

[vorg]

• [x] can't pan with the current orbiter implementation in camera-system