Threads Architecture

Table of Contents

• Main thread
• Update Thread
• Render Thread
• Block Update Thread
• Thread pool

Our design is the fruit of a lot of discussions and headaches.
It is based on 4 "control" threads + a thread pool for parallel tasking.
All of the control threads inherit the AThreadWrapper class

Main thread

This is the main execution thread.

• Handle menus
• Listen for key events and update the Input class
• Instanciates other threads when user wants to play

It is not used for any "gameplay" whatsoever it only setups and instanciates other threads to do these tasks

Update Thread

This is the "gameplay" thread it runs synced with the render thread.

• Entity updates
  • Animation
  • AI pathfinding
  • physics ( sand falling )
• Player update
  • position and camera ( using the input class )
  • health
• GUIs update ( inventories, crafting tables etc... )

During all these tasks this thread will modify the scenes classes for the render thread to use. \ The update threads interacts a lot with the World class that contains all the blocks chunks, entities and the player data.

Render Thread

This is the thread where the magic happens it runs synced with the update thread.

• Reads the scene classes to render frames

The render threads interacts with the renderAPI to render frames using the scenes classes as input

Block Update Thread

This is the thread where blocks are updated... duh. It is capped at 20 iterations per second

• Performs block updates ( piston activation, water falling, trees growing )
• loads chunk when player moves
  • from the file save if possible
  • or generates new chunk
• unloads chunks once the player gets too far
• calculates new meshes if a change occured in a chunk

Thread pool

For every calculations that can be done in parallel

• AI pathfinding
• Calculating new meshes etc...

We use std::async.
Wich uses a thread pool internally