// the find
ianho7/maptoposter-online
✨❤️🔥Turn the cities you love into stunning designs
Browser-based tool that turns OpenStreetMap data into printable city map posters. No backend — everything runs client-side via a Rust rendering engine compiled to WASM. The target user is someone who wants a nice-looking city art print without paying $30 to a Shopify store.
The Rust/WASM rendering pipeline is the right call here — Python/matplotlib would be too slow for interactive use in a browser. The engineering notes are unusually honest about the problems they hit and how they solved them (Douglas-Peucker for subpixel redundancy, two-pass road casing for depth, Overpass area chunking). IndexedDB caching with gzip compression per city is a practical solution to the repeated-generation latency problem. The concurrent Overpass mirror requests with fastest-response-wins is a clever way to paper over the unreliability of public OSM infrastructure.
The WASM binary ships prebuilt in the repo (`src/pkg/wasm_bg.wasm`) which means contributors can't verify what they're running without a full Rust toolchain rebuild — a minor trust issue. There's no way to adjust the map area by drawing a bounding box; you get a radius around a point, which produces ugly results for cities that are long and narrow (Santiago, for instance). The 20 built-in themes are locked behind fixed color presets with no way to save custom themes between sessions — IndexedDB is already there, the feature is just missing. Test coverage appears to be a handful of unit tests on utility functions; the rendering pipeline itself has no automated tests, so visual regressions are invisible until someone notices.