Your opinions on Java Topology Suite, JavaGeom, and GeoRegression?

What’s your opinion of such 2D geometry libraries as Java Topology Suite, JavaGeom, and GeoRegression for performance-oriented games?
Which one performed the best for you?

Years ago, I made a floating point Polygon class that wraps Path2D. I made methods similar to those in java.awt.Polygon. I’m mostly happy with it, but the profiler tells me it ain’t that fast, even though I use the Separating Axis Theorem and fail-fast bounding box checks for intersects(), and object pooling to a fair extent. I suspect Java standard library object methods perform heap allocations liberally under the covers, but I haven’t had time to investigate if this is true.

Is using standard Java library objects for geometry processing the worst choice for performance?

Last time (a month and a half ago) I used java.awt.geom I encountered seemingly arbitrary hanging on Area.subtract (and another similar routine.)

The hang essentially put the thread in some endless loop of memory allocation until it filled up the heap and crashed.

I used a profiler to assure it was Java’s geom library and even recreated it and submitted a bug report. Upon googling, there have been many bug reports of very similar issues (with different datasets.) Even one back in 2004 IIRC.

Otherwise, there have been a few instances where my application hanged for a few seconds due to those methods.

I personally avoid it, I would rather use a third party library. I considered the Java Topology Suite, but I never actually tried it.