Things you can poke at

Interactive explainers for game programmers: engine fundamentals, a real ECS running in your browser, game AI, physics, rendering, networking, and labs for pathfinding, tactical analysis and game feel. Every example runs live, so change it and see what happens.

Foundations

engine

What the hardware and the engine underneath actually do: cache lines and data layout, handles and allocators, fixed timesteps, determinism, spatial partitioning from grids to octrees, job systems, threads and fibers, profiling, and hot reloading code. The "why" under the flecs lessons.

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Lessons

flecs

The flecs entity component system, explained with a live world in every lesson. Add components and watch archetypes form, see which tables a query matches and what it caches, step systems, and fire observers.

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Lessons

game ai

How game agents choose what to do, move and read the map: utility scoring, behaviour trees, goal-oriented and HTN planning, steering and context steering, avoidance from separation to ORCA, formations and terrain analysis, all live so you can watch them think.

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Lessons

physics

How rigid-body engines work, on a small 2D engine you can pause and step: broadphase, contact manifolds, solvers that hold stacks, sleep, fast bodies, joints and characters. Then real Jolt, Box3D and Bullet side by side in your browser, Chaos and PhysX, and wiring physics into flecs through handles.

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Lessons

rendering

How a GPU turns triangles into pixels, on a small software rasteriser you can step a vertex, triangle or pixel at a time: the pipeline and draw calls, edge functions and fill rules, perspective-correct interpolation, MSAA, depth buffers, precision and reverse-Z. More to come on engine-side rendering, lighting and performance.

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Lessons

networking

How networked games hide the network, on one small game over a simulated connection you can make worse: latency, jitter and loss, snapshots and interpolation, prediction and reconciliation, lag compensation, lockstep and rollback.

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Lab

pathing lab

A*, JPS, Theta*, HPA*, navmeshes, roadmaps and vehicle planners searching the same map, step by step and side by side, with terrain costs, unit sizes and several units at once.

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Lab

tactics lab

Terrain analysis for AI on a 2.5D map: clearance, choke points for movement and for sight, traffic, openness, cover generation by scanning and by sampling, exposure to threats, and picking the best cover.

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Lab

feel lab

A platformer with every game-feel setting exposed: acceleration, jump height and timing, fall gravity, coyote time, jump buffering, corner correction, input delay, camera smoothing and juice. Turn one off and feel what breaks.

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Lab

flecs sandbox

A real flecs world in your browser. Define components, create entities, add observers and systems, and watch rows move between archetype tables and sparse storage. Share a link that rebuilds your world step by step.

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Lab

netcode lab

One small game over a simulated network you can make worse, with every model from the networking lessons and their settings in one place: snapshots, interpolation, prediction, reconciliation, lag compensation and rollback.

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Lab

physics lab

A 2D physics sandbox: stacks, chains, ragdolls, a bridge and a car, with every solver, stepping, sleeping, broadphase and continuous-collision setting live and the debug draw on. Or break it on purpose, with each fix one tick away.

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Lab

crowd lab

Hundreds of agents through doors, corridors and over a narrow bridge: A* per agent or shared flow fields, Reynolds and context steering, VO, RVO and ORCA, two setups side by side on the same seed, with throughput, jams and deadlocks measured.

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Lab

frame lab

A frame debugger in miniature on a software rasteriser: step a frame a draw, a triangle or a pixel at a time, click any pixel for every fragment that touched it, and flip depth, culling, blending and sampling to break and fix the classic bugs.

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Lab

procgen lab

Procedural generation step by step: noise and fBm terrain, BSP, TinyKeep-style and cellular-automaton dungeons, wave function collapse, Poisson disc scattering and L-system plants, each from a seed you can share.

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Lab

animation lab

A character rig with its animation systems laid open: sampling and blending clips, blend spaces, state machines, root motion and inverse kinematics.

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