Use bytes for internal RGBA components of Color, iterate particles sequentially in ParticleEmitters, increase limit for CPU particles, reduce size of Particle struct.

TODO.md

@@ -13,9 +13,9 @@
 - ~~Use GUIDs and string ID maps for fetching resources instead of string IDs alone.~~
 - Reimplement unloading.
 - Finalize ResourceManager and ResourceLoader APIs for 1.0.
+- Virtual file system.
 - (stretch goal) Streamed resource loading.
 - (stretch goal) Add async API for ResourceManager.
-- (stretch goal) Virtual file system.
 
 ## Serialization
 
@@ -41,14 +41,15 @@
 - ~~Asset manager~~
 - ~~Separate engine and game into separate projects~~
 - Particle system 2.0
-  - Reduce the size of Particle struct by infering most parameters through lifetime.
-  - Reduce cache misses by utilizing SoA.
-  - SIMD acceleration.
+  - ~~Reduce the size of Particle struct by infering most parameters through lifetime.~~
+  - ~~Reduce cache misses by utilizing SoA.~~
+  - ~~SIMD acceleration.~~
+  - Dynamically resize particle arrays as emitters get added or removed.
 
 ## SceneGraph module
 
-- Layers (sorting mechanism)
 - Full overhaul using Entity Component architecture (not to be mistaken with ECS).
+- Layers (sorting mechanism)
 - Save/load scenes from file
 
 ## Input