Code examples for the C and C++ APIs and for Flecs Script. Each page shows the example in every language it is available in. The sources live in the examples folder of the repository.

Hello world

Entities

Basics (C, C++)
Cpp traits (C++)
Emplace (C++)
Fwd declare component (C)
Get n (C++)
Hierarchy (C, C++)
Hooks (C, C++)
Iterate components (C, C++)
Multi set get (C++)
On validate (C, C++)
Parent hierarchy (C, C++)
Prefab (C++)

Game mechanics

Modules

Simple module (C, C++)

Observers

Basics (C, C++)
Custom event (C, C++)
Enqueue entity event (C, C++)
Enqueue event (C, C++)
Entity event (C, C++)
Monitor (C, C++)
Propagate (C, C++)
Two components (C, C++)
Yield existing (C, C++)

Prefabs

Basics (C, C++)
Hierarchy (C, C++)
Nested prefabs (C, C++)
Override (C, C++)
Slots (C, C++)
Typed prefabs (C++)
Variant (C, C++)

Queries

Basics (C, C++)
Change tracking (C, C++)
Component inheritance (C, C++)
Cyclic variables (C, C++)
Each callback (C++)
Each w entity callback (C++)
Each w iter callback (C++)
Facts (C, C++)
Find entity (C++)
Group by (C, C++)
Group by callbacks (C, C++)
Group by custom (C, C++)
Group iter (C, C++)
Group iter all (C, C++)
Hierarchies (C)
Hierarchy (C++)
Iter info (C++)
Iter targets (C, C++)
Run callback (C++)
Setting variables (C, C++)
Singleton (C, C++)
Sorting (C, C++)
Transitive queries (C, C++)
Variables (C, C++)
Wildcards (C, C++)
With (C++)
Without (C++)
World query (C++)

Reflection

Auto define enum (C, C++)
Auto define nested struct (C, C++)
Auto define struct (C, C++)
Basics (C, C++)
Basics bitmask (C, C++)
Basics deserialize (C, C++)
Basics enum (C, C++)
Basics json (C, C++)
Custom serializer (C, C++)
Entity type (C, C++)
Member ranges (C, C++)
Nested set member (C, C++)
Nested struct (C, C++)
Portable type (C++)
Query to custom json (C, C++)
Query to json (C, C++)
Runtime component (C, C++)
Runtime nested component (C, C++)
Ser opaque string (C)
Ser opaque type (C, C++)
Ser opaque vector (C)
Ser std optional (C++)
Ser std string (C++)
Ser std vector (C++)
Units (C, C++)
World ser deser (C, C++)

Relationships

Script

00 town (Flecs Script)
01 basics (Flecs Script)
02 components (Flecs Script)
03 variables (Flecs Script)
04 entity kind (Flecs Script)
05 prefabs (Flecs Script)
06 strings (Flecs Script)
07 annotations (Flecs Script)
08 if statement (Flecs Script)
09 for loop (Flecs Script)
10 grid (Flecs Script)
11 procedural asset (Flecs Script)
12 template interface (Flecs Script)
13 template inheritance (Flecs Script)
14 slider (Flecs Script)
15 checkbox (Flecs Script)
16 dropdown (Flecs Script)
17 radio group (Flecs Script)
18 mixer (Flecs Script)
19 lights out (Flecs Script)
20 city grid (Flecs Script)
21 solar system (Flecs Script)
Expr run (C)
Expr w vars (C)
Functions (C)
Rest call (C)
Script managed (C)
Script run (C)

Systems

Basics (C, C++)
Custom phases (C, C++)
Custom phases no builtin (C, C++)
Custom pipeline (C, C++)
Delta time (C, C++)
Each callback (C++)
Each w entity callback (C++)
Each w iter callback (C++)
Immediate (C, C++)
Multiple queries (C++)
Mutate entity (C, C++)
Mutate entity handle (C++)
Pipeline (C, C++)
Run callback (C, C++)
Run to each callback (C++)
Startup system (C, C++)
Sync point (C, C++)
Sync point delete (C, C++)
System ctx (C, C++)
Target fps (C, C++)
Time interval (C, C++)