powerfulbacon/corgeng

A modularised, multi-threaded C# game engine based on the Entity Component System architecture. Uses OpenGL for rendering and contains many optional modules for easier development. Includes a user interface library, networking, a layered rendering solution, dynamic XML content loading, ECS framework and an example programs. Primarilly for 2D games.

Some things I have worked on:

Space Station 13 Fancy Lighting

A beautiful shadow based lighting system utilising some fun transformation math. Unfortunately due to the restrictions of the engine, I was unable to overcome the client lag caused by Byond's KEEP_TOGETHER flag causing lag when rendering lights.

Random art

GGJ2022

Some screenshots of a rimworld inspired game I made in 10 days for the global game jam 2022.

corgeng's Issues

Casting is very slow

User interface text component

Ability to draw text.
Text will automatically resize to fit the container

Add in checks for when model or texture loading is not on the main thread

Update events overload the system and make it kablooey

Keyboard presses raise a global event every rendering frame.
If the system waiting for keyboard events runs slower than the rendering thread, the events come in faster than they can be processed which completely overloads the system.

Better event trace handling

If an exception occurs as a result of some processing, then the event that caused that process should have a stack trace generated and printed out.
Obviously we can't generate the stack trace for every event, and we should only do it when we error if possible.

This would make it significantly easier to diagnose issues that occur as a result of a sequence of events rather than issues that occur in isolation.

Image User Interface Component

Add in signal priority / some way to intercept signals

If we send a keyboard event we need some way of catching it with a priority: If the menu is open a keypress shouldn't affect all systems but be caught by the menu system before being passed down to others

Synchronous events prevent the game from closing

If something is waiting for a synchronous event to be completed, but the target subsystem shuts down then the waiting thread will be frozen forever which prevents the game from closing.

Keybinds

There should be a basic keybind framework, so rather than checking if a key was pressed we can detect when a keybind is pressed

User interface tags

Implement tags for user interface components.
Add the ability to get a component with some tag.

This allows us to open up user interface components when we click a button.

Port the texture data file thing from GJ2022

Contents

We need to be able to put entities inside of other entities.

Add in ITextureSprite

Make it so we can get a texture and the position of that sprite within a texture.

CreateEntity is very slow due to synchronous events.

We should rewrite synchronous events to work like this:

• If the system is currently running on its own thread, tell it to pause
• Wait until the system is paused and all synchronous events are handled on that system.
• Run our event on the thread that the synchronous event was called from.

In most cases the entity system will be sleeping, meaning that we can skip straight to immediately executing the event on the current thread which saves time while keeping entitysystems non-concurrent.

Add in "parent" for content loading

Entity should support the "parent" attribute, which lets something inheret all properties from another entity definition.

At 25000 entities, rendering completely breaks

Rendering breaks and the program drops FPS as soon as we hit an entity count of 25000

World doesn't support the same entity in different maps

Each entity only has a single contents index, but they can be in multiple track lists at the same time which can cause issues.

Rendering locks the batches

This will slow down other entity systems as they can't update the batch until drawing is done.
Use double buffering instead.

Create design document for Rendering module

Dynamic content loading

Way to define prototypes without creating them.

I need a way to define prototypes without actually creating and then deleting an entity.
Perhaps this should be integrated into the ContentLoading system and that should be refactored.

Workaround:

• Create an entity
• Generate prototype from entity
• Delete the entity

ProcessingSystems don't handle priority queue.

ProcessingSystems don't consider the priority queue, and as such synchronous events will run forever

OnComponentRemoved should not be called when an entity is deleted

It creates events fired on entities that have no components, because they are deleted.

OnComponentAdded gets called twice?

Text can be dynamically moved, changed and redraws automatically

Networking Notes

We need to transmit component add and remove events.
When a player joins they need to recieve the current state of entities and events.
Not all components need to be networked.
Not all entities need to be networked.
We need to figure out how to decide what should render what.
We need to transmit relevent server side events so that clients can handle them.

Renderable Component

Complete the sprite renderable component

Content Loading Lists

Content loading needs the ability to be able to load in lists.

<Property name="BehaviourList">
  <Object type="List">
    <ListElement>4</ListElement>
    <ListElement>5</ListElement>
    <ListElement>6</ListElement>
  </Object>
</Property>

<Property name="BehaviourList">
  <Object type="List">
    <ListElement>
      <Object type="BehaviourNode">
        <Property name="Priority">5</Property>
      </Object>
    </ListElement>
    <ListElement>
      <Object type="BehaviourNode">
        <Property name="Priority">5</Property>
      </Object>
    </ListElement>
  </Object>
</Property>

Issues with sprite rendering component

There seems to be some kind of issue with batches or at least the sprite rendering component in general, where sometimes things don't render and deleting them causes other things to stop rendering instead.
Is this a case of something not being added to the list, causing the offsets to shift by 1?

We need regular interval processing

Want:

//1 second delay
override double ProcessDelay = 1000;

RegisterProcessEvent<GComponent>(targetEntity, OnProcess);
UnregisterProcessEvent(targetEntity);


void OnProcess(IComponent component, double deltaTime)
{
    ...
}

Text Rendering Goals

• Ability to render text
• Changing the text or position of the text, or any variables will automatically update the batch and update the text object without more required updates.

Linux support / Move to .NET Core

Supporting as many operating systems as possible is a good thing, since it means we have more audience for games created using CorgEng. We need to move to .NET Core instead of .NET framework to accomodate anyone who suffers the fate of linux.

Add in content loading unit tests

Content loading requires unit tests to validate it is working properly

Add in a way for systems to register update events.

Add a way for a system to register an update event that will be automatically triggered every few milliseconds (passed in via a parameter).

Text component

Convert signals to tasks and have it possible to await their handling

Make it so we can await the completion of a task, the thread executing will wait until the task is handled before continuing.
Alternatively we could handle the task on that thread instead of going through the system, however this would result in complications with multi-threading if the system/component has shared reasources.

Unit tests do not work with github actions

There is an error with the csproj file

Multi-threaded systems

Make systems multi-threaded.
When a signal is sent it will be handled on the appropriate thread.

Implement texture caching

Content Loading Snippets/Defines

Add in the ability to create content loading blueprints, which can be used inside other content loading xml files and act as a replacement.

Example idea:

<Define name="group">
  <Property name="value">5</Property>
</Define>

<Object type="NumberHolder">
  <Define name="group" />
</Object>

Overlay rendering

We need a way to render overlays onto an already rendering object (Clothes and stuff need drawing)

Ability to apply custom properties to user interface components from XML file

Add in global events

Allows systems to register to global events, which will trigger a system callback when triggered.
These will include keyboard and mouse events.

Component has pretty high memory usage.

Due to having lambda functions per event registered to component per component, the component signal handler lambda functions use an absolute ton of memory.

Before entities created (Its high due to reflection caches mainly):

With somewhere between 32000 and 64000 entities:

Its not awful, but something to consider optimising

Potentially rework AI behaviour

After using the AI behaviour system in implementations, there are some clear flaws, mainly with the memory system causing issues with claiming when tasks fail or are cancelled.

Perhaps it would be better to do something like:

• Memory is local, you pass on calculated things in chain

Currently the tree looks like this:

The memory system is just messy

Removing from a batch is bugged

There is a bug with removing from batches which causes failures when trying to change a sprite.
Reproduce by making something render, removing it from the batch then change some texture for an item in the batch after the thing

We are limited to 64 locks - meaning only 64 entity systems.

We need to rewrite this with our own task manager, rather than using the systems threads which can result in poor performance and may lead to slow down of the rendering thread.

User interface buttons

Rewrite the ReadMe

The process doesn't terminate when the window is closed