Credits
Every Source, Named
Nothing on a print is ours alone. These are the people and projects it stands on. The same list is kept as data at /sources.json.
Last updated
The survey
- Every court, path, tree, fence and building: © OpenStreetMap contributors, under the Open Database License 1.0. Every print credits them in its margin, with the date the data was read.
- Search: Nominatim, run by the OpenStreetMap Foundation, asked only when you press the button, as its usage policy asks.
- The survey of each club: the Overpass API, from the main instance run by FOSSGIS e.V., and from VK's public instance when the main one is busy.
- Tagging: the tennis page of the OpenStreetMap wiki, CC BY-SA 2.0.
The rules
- The court: ITF Rules of Tennis 2026, Rule 1. A doubles court is 23.77 m long and 10.97 m wide, the singles court 8.23 m, the service line 6.40 m from the net. Every line on a print is set from these, and the run-off round a court from Appendix X.
- The score: the same rules, Rules 5 to 7 and Appendix VI, which set the tiebreak, the match tiebreak and the alternative scoring methods the studio accepts.
The lengths
- T. Vincenty's inverse formula for geodesics on the ellipsoid, Survey Review 23(176), 88 to 93, April 1975, doi:10.1179/sre.1975.23.176.88.
- C. F. F. Karney, Test set for geodesics, CC0. Our tests hold every length to it within 1 mm.
The type
- Big Shoulders Display, by The Big Shoulders Project Authors, SIL Open Font License: the court numbers, the scores and the headings.
- Public Sans, by The Public Sans Project Authors at the U.S. Web Design System, SIL Open Font License: everything else.
- Gloock, by Duarte Pinto, SIL Open Font License: the titles on Gilt and Watercolour prints.
The rooms
The four rooms in On Four Walls are generated pictures, carried from Painted Miles by way of Painted Course, the Painted studios this one was built from.