Laser Labyrinth — Reflection & Refraction (2D)

Laser Settings

Launch angle 30°

Max bounces 10

Glass IOR n₂ 1.50

Levels

Tools

Click empty canvas to place the selected object. Drag an object to move it. Scroll over an object to rotate it 5° per notch.

Live readout

Reflections

Refractions

Total int. reflection

Path length

0 px

Critical angle θc

41.8°

Target hit

✗

How it works

A single ray is cast from the source at the launch angle and traced segment by segment: at every step the engine finds the nearest surface it crosses among the mirrors, glass blocks, the four canvas walls and the target circle, using exact ray–segment and ray–circle intersection formulas — never a pixel scan.

Reflection:  r = d − 2(d·n)n
Refraction:  n1·sin θ1 = n2·sin θ2   (Snell's law)
Critical angle:  θc = arcsin(n1/n2)

At a mirror the ray reflects with the vector formula above. At a glass face it refracts by Snell's law using the IOR slider as n2 (air is fixed at n1 = 1.0); if the transmitted sine would exceed 1, Snell's law has no real solution and the ray undergoes total internal reflection instead — the TIR counter tracks exactly those events, separately from ordinary mirror bounces. The critical-angle readout recomputes θc = arcsin(1/n2) live as you move the IOR slider, so you can predict TIR before it happens rather than only observe it after.

Recursion stops at the bounce-limit slider or when the ray reaches the orange target circle, whichever comes first. This is the same laser-maze mechanic as the 3D version, rebuilt on a plain 2D canvas so the ray-tracing geometry itself — not a WebGL scene — is what you are looking at.

Laser beam Mirror Glass block