https://github.com/friflo/ecs-wiki
C# Documentation: friflo ECS
https://github.com/friflo/ecs-wiki
csharp data-oriented-design ecs ecs-framework entity-component-system wiki
Last synced: 3 months ago
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C# Documentation: friflo ECS
- Host: GitHub
- URL: https://github.com/friflo/ecs-wiki
- Owner: friflo
- Created: 2024-07-24T13:51:00.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-06-18T08:04:55.000Z (4 months ago)
- Last Synced: 2025-06-18T09:20:55.644Z (4 months ago)
- Topics: csharp, data-oriented-design, ecs, ecs-framework, entity-component-system, wiki
- Homepage: https://friflo.gitbook.io/friflo.engine.ecs
- Size: 808 KB
- Stars: 12
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
[](https://github.com/friflo/Friflo.Engine.ECS)
[](https://github.com/friflo/Friflo.Engine.ECS)
[](https://github.com/friflo/Friflo.Engine.ECS)
[](https://github.com/friflo/Friflo.Engine.ECS-Demos)
[](https://github.com/friflo/Friflo.Engine-docs)
[](https://discord.gg/nFfrhgQkb8)
[](https://github.com/friflo/ECS.CSharp.Benchmark-common-use-cases)
**friflo ECS**, a small and high-performance **C# ECS** - Entity Component System.
Its an archetype based ECS with focus on performance and simplicity.
🛈 What is an Entity Component System?
An Entity Component System (**ECS**) is a software architecture pattern. [Wikipedia](https://en.wikipedia.org/wiki/Entity_component_system).
It is often used in software development for **Games**, **Simulation**, **Analytics** and **In-Memory Database** providing high performant data processing.
An ECS has two major strengths:
1. It enables writing **highly decoupled code**. Data is stored in **Components** which are assigned to objects - aka **Entities** - at runtime.
Code decoupling is accomplished by dividing implementation in pure data structures (**Component types**) - and code (**Systems**) to process them.
2. It provides **high performant query execution** by storing components in continuous memory to leverage L1 CPU cache and its prefetcher.
It improves CPU branch prediction by minimizing conditional branches when processing components in tight loops.
[Data-oriented design ⋅ Wikipedia](https://en.wikipedia.org/wiki/Data-oriented_design).
## Design goals
🔥 High Performance
Optimal and efficient query / system execution.
Fast entity creation and component changes.
🎯 Simple
Simple API - convenient to debug.
No boilerplate code.
🔄 Low memory footprint
Minimal heap allocations at start phase.
No heap allocations after internal buffers grown large enough.
No GC pauses / no frame drops.
🛡️ Reliable
100% verifiably safe C#. No unsafe code or native bindings.
Full test coverage. Expressive runtime errors. Actively maintained.
Your code requires no Unsafe quirks for maximum performance.
🤏 Small
Friflo.Engine.ECS.dll size: only 320 kb.
No code generation. No 3rd party dependencies.
# Overview
A common ECS provide the basic features listed bellow.
To solve other common use-cases not covered by basic implementations this ECS provide the listed extensions.
## Basic features
> An ECS acts like an in-memory database and stores entities in an [EntityStore](docs/entity.md#entitystore) aka *World*.
> An [Entity](docs/entity.md) is a value type - aka `struct` - with a unique `Id`.
> Data is stored in [Components](docs/entity.md#component) added to entities.
> Components are stored highly packed in continuous memory.
> The major strength of an archetype based ECS is efficient and performant [Query](docs/query.md) execution.
> [Query filters](docs/query.md#query-filter) are used to reduce the amount of components returned by the query result.
## Extended features
> Support [Events](docs/events.md) to subscribe entity changes like adding or removing components.
> Event handlers can be added to a single `Entity` or the entire `EntityStore`.
> [Index / Search](docs/component-index.md) to enable lookup entities with specific component values. **v3.0.0**
> A lookup for a specific component value - aka search - executes in **O(1)** ~ 4 ns.
> *Possibly the first and only ECS that supports indexing.*
> [Relationships](docs/relationships.md) to create links between entities. **v3.0.0**
> A link is directed and bidirectional. Deleting *source* or *target* entity removes a link.
> [Relations](docs/relations.md) to add multiple *"components"* to an entity. **v3.0.0**
> Relations are not implemented as components to avoid *archetype fragmentation*.
> [Systems](docs/systems.md) are optional. They are used to group queries or custom operations.
> They support logging / monitoring of execution times and memory allocations in realtime.
> [Hierarchy / Scene tree](docs/entity.md#hierarchy) used to setup a child/parent relationship between entities.
> An entity in the hierarchy provide direct access to its children and parent.
> [JSON Serialization](docs/entity.md#json-serialization) to serialize entities or the entire EntityStore as JSON.
## Library
> 100% verifiably safe 🔒 C#. No [*unsafe code*](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/unsafe-code)
> or native bindings.
> This prevents *segmentation faults* or *access violations* crashing a process instantaneously.
> Minimal heap allocations.
> After internal buffers grown large enough no heap allocation will occur.
> At this point no garbage collection will be executed. This avoids frame stuttering / lagging caused by GC runs.
> Especially no allocation when
> - Creating or deleting entities
> - Adding or removing components / tags
> - Adding or removing relations or relationships
> - Emitting events
> - Changes in entity hierarchy
> - Query or system execution
> Aims for 100% test coverage:
> Code coverage: [](https://app.codecov.io/gh/friflo/Friflo.Engine.ECS/tree/main/src/ECS)
# Project
[Release Notes](package/Release-Notes.md) - document all nuget releases.
[Library](package/Library.md) describes assembly specific characteristics.
[Unity Extension](extensions/Unity-extension.md) with ECS integration in Unity Editor.
## External Links
GitHub: [https://github.com/friflo/Friflo.Engine.ECS](https://github.com/friflo/Friflo.Engine.ECS)
Discord: [friflo ECS](https://discord.gg/nFfrhgQkb8)
Benchmark: [C# ECS Benchmarks](https://github.com/friflo/ECS.CSharp.Benchmark-common-use-cases)
## GitHub
[](https://github.com/friflo/Friflo.Engine.ECS)
💖 In case you like this project?
Leave a ⭐ on [GitHub ⋅ friflo/Friflo.Engine.ECS](https://github.com/friflo/Friflo.Engine.ECS)