The figure library

No figure on this site is a drawing that was made once and saved. Each one is a function: it takes parameters and returns SVG, so the same generator produces the 27° twist and the 5° twist without either being redrawn.

That is the reason the collection can keep growing without the illustrations drifting apart. A generator is written once, checked once, and every essay that calls it inherits the same line weights, the same colour roles, and the same behaviour in dark mode. There are 161 of them. The most-used — lettering-search — is called by 27 essays; the least-used by one.

Ordering them by how many essays call each one is new, and it is the point of this page rather than a nicety. A generator written for one essay and never called again is a design failure — it means an argument was drawn rather than a mechanism understood — and until this page existed the only way to notice was a number in a ledger. Now the tail is visible: the generators at the end of the list are the candidates for parameterising into something a second essay can use.

Each of them now has a page of its own, and what those pages carry is not the picture — it is what the generator checked before it drew. A crease pattern here goes past four theorems at every interior vertex, and until this phase the only evidence that it had was a build that did not crash: a passing assertion left nothing behind, so the account of what this code verifies lived in prose, and prose about what code does drifts in one direction only. It is measured now, by running each generator with a listener on its assertions. 161 of the 161 made a claim during this build, 1649 distinct claims between them — and the eleven that made none say so on their own pages, which is the point of measuring rather than listing.

Several of these draw patterns a reader can print and fold. Those are collected on the patterns page, with a sheet at true scale and a FOLD export for each.