Document waveform visualizer types

README.md

@@ -118,11 +118,23 @@ counter, since seeking a live stream isn't meaningful.
 
 ### Waveform visualizer
 
-`WAVEFORM_ENABLED=true` shows a real-time scrolling waveform that builds out as
-the stream plays (it appears only after the listener presses play). It uses the
+`WAVEFORM_ENABLED=true` shows a real-time visualizer that builds out as the
+stream plays (it appears only after the listener presses play). It uses the
 Web Audio API — an `AnalyserNode` fed by the `<audio>` element — and paints
-peaks onto a `<canvas>` themed with your accent color. Tunable via
-`WAVEFORM_HEIGHT`, `WAVEFORM_COLOR`, and `WAVEFORM_WINDOW_SECONDS`.
+onto a `<canvas>` themed with your accent color. Tunable via `WAVEFORM_HEIGHT`,
+`WAVEFORM_COLOR`, and `WAVEFORM_WINDOW_SECONDS`.
+
+There are several render styles: `bars` (default, scrolling peak history),
+`line` (oscilloscope), `vu` (single level meter), `spectrum` /
+`spectrum-mirror` (frequency bars), `blob` (smoothed filled area) — these six
+render below the art and are mutually exclusive — plus `circular` (a ring
+around the art) and `glow` (the art pulses with loudness), which are
+independent toggles that can combine with a below-art style and with each
+other. Set `WAVEFORM_TYPES` (comma-separated) to expose more than one; a
+small picker then appears letting each visitor choose their own combination,
+remembered in their browser. `WAVEFORM_DEFAULT` sets what's active before a
+visitor picks anything. Leaving both unset behaves exactly like before this
+setting existed: `bars` only, no picker.
 
 Two important caveats: