cds-astro / cds-healpix-rust

The CDS HEALPix library in Rust (WebAssembly, Python, ...)
Apache License 2.0
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Sph geom polygon/parallel intersection #3

Closed bmatthieu3 closed 2 years ago

bmatthieu3 commented 2 years ago

This is a contribution that includes a method for computing the intersection between a polygon and a parallel (which is not a great circle). I also give the possibility to the user to retrieve the coordinates of the intersection between a polygon and a great circle arc.

These features are used by aladin lite to get the intersections between meridian and parallel grid lines with the user FoV. These intersection vertices are used to plot the labels for the grid lines. This could be great if those features are included into cdshealpix so that we can have only one base of code for doing that instead of having duplicate codes in aladin lite and cdshealpix doing the same thing. For a future extent, we could separate sph_geom module into a proper (and more complete) spherical geometry crate because one could imagine that those features would be beneficial to other applications.