The signal-side SHAPE of a stereo image: a phosphor trace of the channel pair rotated 45 degrees so mono runs straight up the middle, pure side lies flat across the horizontal, and a hard-left source draws on the left. Diamond graticule, an L-R baseline carrying the measured energy balance, a correlation meter whose lower half is tinted, and a CORR/WIDTH readout. Switchable between the mid/side diamond and a raw left/right split, which answers the per-channel question the diamond hides. Display auto-gain measured on the mono sum, so the scale never depends on which way the image leans, and the printed readings are always taken from the raw pair. Takes a live analyser pair or a getStereoData callback; with neither it draws its graticule and says it has no source rather than animating invented samples.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-goniometer.json"