This projects contains a port of JTS to scala. The rationale is the need to use it in both scala and scala.js.

The conversion was done using IntelliJ but the conversion is far from perfect and manual tweaking is required. For the same reasons bugs are expected. Ideally more tests should be included

Note: Only the minimal amount of code to use JTS in gsp-math was ported, about 150 classes

• Lots of code use non generic java util collections. They need to be adjusted manually
• Ports of for loops can be messy, especially if they include break/continue
• Field initialization can be messy, in some cases fields are read before they are initialized
• Some classes use TreeMap which is not supported in scala.js. Those need to be converted to scala.TreeMap

Only one test has been included to fix a bug. Ideally more should be converted. They don't need to run on java but may need to be adjusted to work with the scala code

A small awt package is also included but that is just a copy of the awt package as in the original java code It is only meant to be used on the JVM obviously

The bulk of the port tracks JTS 1.18.0, commit 16023a11a6b96940fefc811399501296fe00f541: https://github.com/locationtech/jts/commit/16023a11a6b96940fefc811399501296fe00f541

Since then, selected pieces have been brought forward to the JTS 1.20.0 tag, commit 6e95fe82feb986a7aa657f4ffa406d8c290af509, as self-contained vertical slices (a full 1.18→1.20 sync is not viable — the original port was never a complete snapshot). What was ported from 1.20.0:

• operation.relateng — the RelateNG relate engine (upstream PR #1052). It now backs every Geometry binary predicate (contains, intersects, covers, …) and relate(), which therefore also accepts GeometryCollection operands. This replaces the legacy topology-graph-based relate path and is significantly faster for predicate evaluation.
• Supporting dependencies: index.hprtree (packed Hilbert R-tree), algorithm.PolygonNodeTopology, and noding.MCIndexSegmentSetMutualIntersector.
• Two correctness fixes surfaced by porting the upstream RelateNG test suite: DD-precision line Intersection, and WKT MULTIPOINT EMPTY-element handling.

So: most classes are at 1.18.0; the relate engine and its dependencies are at 1.20.0.