The log-frequency / dB plot as pure maths: an axis factory with both forward and inverse mappings, RBJ biquad magnitudes for all seven cookbook shapes, and cascaded curve/path builders. No React, no DOM — so a display and a drag overlay can share one scale, and the geometry can be tested in Node.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-response-geometry.json"No files included in this item.