Appendix E

Generators and Effects

The 20 procedural sources a generative scene can draw from, and the 8 effects that can be layered over any scene. Each entry lists what a knob can reach under its name while the show is running. Appendix F is the same parameters the other way round: one row each, with every generator or effect that declares it.

Generators#

Set one as a generative scene's source. Every generator renders at 320×200 and is downsampled by whichever display mode is in force.

[[scenes]]
type = "generative"
source = "plasma"    # any generator below

A parameter below is reached live as source.NAME — a knob on this scene's source is mapped with target = "source.speed". It moves nothing unless the generator declaring it is the one on screen.

Generator	Description
`plasma` `speed` `0 – 2` `scale` `0.1 – 4`	Classic sine-sum plasma whose hue cycles over time.
`tunnel` `speed` `0 – 2` `scale` `0.25 – 4`	Infinite-zoom tunnel: hue is driven by per-pixel depth (1/radius) and angle, scrolled over time.
`fire` `scroll_speed` `0 – 4` `intensity` `0.2 – 2`	Rising fire: an upward-scrolling turbulence texture masked by a bottom-hot vertical gradient and color-mapped black→red→yellow→white (`cv2.COLORMAP_HOT` — a near-perfect match for the C64 palette).
`mandelbrot` `zoom_speed` `0.02 – 1` `cycle_speed` `0 – 2`	Escape-time Mandelbrot zoom.
`moire2` `ring_freq` `10 – 80` `drift_speed` `0 – 2`	Two concentric-ring distance fields whose centers drift apart and together, summed into a classic moiré interference pattern (each field is `sin(distance-to-center * freq)`; xscreensaver's moire2.c gets the same beat pattern by XOR-compositing two arc bitmaps — this is the closed-form equivalent: a distance field instead of drawn arcs).
`halo` `drift_speed` `0 – 2` `pulse_speed` `0 – 3`	Several soft-edged halos drifting on independent circular orbits, additively blended (bright where they overlap, no clear — matching xscreensaver's halo.c un-erased canvas).
`epicycle` `speed` `0 – 2`	Fourier epicycles: a chain of circles, each spinning around the tip of the previous, whose combined tip traces `sum_i r_i * exp(j*(w_i t + phi_i))` — a chain of rotations composes to the same vector sum regardless of framing, so this sums phasors directly rather than nesting rotations.
`hopalong` `shape` `-2 – 2` `drift_speed` `0 – 1`	Hopalong chaotic point-map attractor, iterated for many parallel starting points at once (numpy-vectorized across the batch — each step is still sequential, the map depends on the previous point) into a density accumulator, color-mapped by (log-scaled) density.
`rorschach` `grow_speed` `0 – 4`	Mirrored-symmetric ink-blot: a precomputed 2D random walk (fixed seed → deterministic) cumulative-summed from Gaussian steps, progressively revealed as `t` advances and reflected across the vertical center line — xscreensaver's rorschach.c animates the same way (draw a few more walk points each frame); this stays a pure function of `t` by redrawing however much of the (fixed) walk is "revealed" by `t` from scratch each frame, rather than accumulating pixels frame to frame.
`hiphotic` `speed` `0.1 – 8` `scale` `0.1 – 4`	WLED "Hiphotic" port: nested trig interference (`sin(cos(x...) + sin(y...) + a)`), reimplemented in continuous float instead of WLED's 8-bit sin8/cos8 lookup tables.
`metaballs` `speed` `0.05 – 5`	WLED "Metaballs" port: 3 moving "ball" centers blended into a classic inverse-distance metaball field.
`rotozoomer` `speed` `0 – 4` `scale` `0.2 – 4`	WLED "Rotozoomer" port: a static XOR bit-pattern texture (`(x4) ^ (y4)`, precomputed + colorized once) sampled through a rotating/zooming affine transform.
`lissajous` `speed` `0 – 4` `scale` `0.2 – 6`	WLED "Lissajous" port: a classic XY curve (`x = sin(thetafreq_x + phase)`, `y = cos(theta2 + phase)`) sampled at a fixed number of points along its parametrization.
`dna` `speed` `0 – 3` `scale` `0.3 – 4`	WLED "DNA" port: two sine strands sweeping the full frame width, phase-shifted by half a cycle (`pi`, matching WLED's `i4` vs `i4+128` offset) so they wind around a shared center line like a double helix; color cycles per column + time.
`drift` `speed` `0 – 3` `scale` `0.3 – 2`	WLED "Drift" port: a rotating spiral trail — for radii `i` stepping outward from center, a point at angle `t*(maxDim-i)` traces a full spiral arm every frame.
`colored_bursts` `speed` `0 – 3` `scale` `0.3 – 3`	WLED "Colored Bursts" port: several lines burst from one common, slowly-orbiting point out to per-line endpoints that trace their own faster orbits — WLED's shared start point has no per-line phase offset, while the per-line `i24`/`i48+64` phase spread on the other endpoint is what fans the lines out into a burst.
`dotswarm` `speed` `0 – 3` `scale` `0.2 – 2`	A WLED "beatsin dot swarm" port covering the shared shape of several kin effects — Black Hole, Frizzles, Sindots, Squared Swirl, Drift Rose — which all boil down to the same primitive: a handful of points, each independently orbiting via a bounded sine (`beatsin8` in WLED) at its own frequency, color-cycled and blended.
`game_of_life` `speed` `0.1 – 4`	WLED "Game Of Life" port: Conway's Game of Life on a coarse grid (chunky upscaled cells — reads great after C64 quantization, especially on PETSCII), with WLED's signature parent-color inheritance (a newly-born cell's hue is the mean of its live parents' hues).
`soap` `speed` `0 – 3` `scale` `0.2 – 3`	WLED "Soap" port: a persistent color buffer smeared/advected each tick by a slowly-rotating noise-driven flow field — the classic swirling soap-film look.
`fireworks` `speed` `0 – 3` `scale` `0.3 – 3`	WLED "Fireworks" port — the flagship of WLED's shared particle-system engine, which also drives Volcano/Ballpit/Waterfall/Impact/Attractor/ Galaxy as different emitter/gravity presets on the same primitive; only the fireworks preset is ported here.

Effects#

Named by a scene's effect, or chained in order with effects. An effect transforms the frame after the source has drawn it and before the display mode quantizes it.

[[scenes]]
type = "generative"
source = "plasma"
effects = ["mirror", "trails"]  # in order

A parameter below is reached live as effect.NAME, and applies to whichever effect in the chain declares it.

Effect	Description
`trails` `decay` `0 – 0.96`	Feedback / echo trails: each frame is max-blended with a decayed copy of the previous output, so moving content leaves a fading comet tail.
`pulse` `intensity` `0 – 2.5`	Beat-punch zoom: a transient punches the frame scale up (zoom-in toward center), relaxing back as `onset` decays; sustained loudness adds a gentle steady zoom.
`rgb_shift` `intensity` `0 – 2.5`	Chromatic split: a transient slews the red and blue channels apart horizontally (opposite directions), an RGB-shift glitch shudder that snaps on the beat and relaxes as `onset` decays; loudness adds a steady split.
`blur` `intensity` `0 – 8`	Gaussian blur (`cv2.GaussianBlur`) — the first blur primitive in the codebase, added as an enabler for future dot/trail-family generator ports (WLED leans on `SEGMENT.blur` throughout its 2D effects).
`strobe` `duty` `0.05 – 1` `rate` `1 – 16`	Tempo-locked strobe: blanks the frame to black for part of every beat, so the picture flashes on the grid.
`invert` `mix` `0 – 1`	Photo-negative: blends the frame toward its color inverse (`255 - px`).
`mirror` `axis` `3 values`	Symmetry fold: reflects one half of the frame onto the other, the classic VJ kaleidoscope-lite look.
`posterize` `levels` `2 – 32`	Level crush: quantizes each channel to `levels` steps, flattening the image into hard poster bands (a look that also pre-simplifies the frame for the C64 palette reduction downstream).

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