Overview

File	Responsibility
main.cpp	Startup, input handling, state management, render loop
axisWidget.hpp/.cpp	Corner orientation widget (mini axes + labels)
vortexLoader.hpp	.surf parsing, colour palette, geometry construction
shader.hpp	Shader compilation and program linking
vectorMath.hpp	4D vector/matrix math and rotation generators
uniforms.hpp	Cached uniform locations, per-frame upload
objects.hpp	Vertex, Triangle, lattice extent globals
stateLog.hpp	Binary shared-state read/write for window sync

Rendering

Two shader programs share a vertex stage:

1. Vertex stage (vertex.glsl): folds each vertex into the periodic image nearest the selection centre, applies the combined 4D rotation, and projects 4D to 3D with a perspective divide on the rotated w coordinate.
2. Geometry stages (geometryLines.glsl, geometryTriangles.glsl): cull primitives outside the focus radius or time slab, re-wrap vertices, and reject wrap-around edges longer than 1.5 lattice units.
3. Fragment stages: distance-based alpha fade (smoothstep-like easing) and green highlight for the selected primitive ID. The line variant discards fragments below 0.3 alpha.

Geometry is built CPU-side by vortexLoader.hpp: each surface element becomes four vertices, two triangles, and eight line endpoints (four outline edges). The timeslice cones are rebuilt dynamically into a separate buffer whenever t0 changes.

State flow per frame

input (keyboard/mouse)
    -> update angles, R_spatial, selection centre, t0
    -> combine R = R_spatial * XW * YW * ZW rotations
    -> write SharedState file (if focused)
    -> upload uniforms, draw passes:
         1. translucent triangle faces (depth writes off)
         2. line outlines (depth writes on)
         3. timeslice cones (mode 3)
         4. axis widget (own viewport, orthographic)
         5. SFML overlay: widget labels + HUD text