NOTE: Work in Progress
The FORSE (Fast Overlay with Robust Streaming Evaluation) engine incorporates a new approach to vector overlay. It provides:
- High Performance - FORSE offers exceptional performance on all input datasets up to very large size.
- Robust - Several techniques are incorporated to provide 100% robust evaluation. These include exact evaluation of determinant sign, high-precision intersection computation, and snap-rounding.
- Streaming Evaluation - FORSE is able to operate on data streamed in from external memory. The resultant output is also streamed out. This means that very large datasets can be processed with only a small memory footprint. The only requirement is that the input data must be sorted along the X axis, which is easily accomplished.
- Memory efficiency - The FORSE internal memory structures are optimized for minimal size. Memory usage is sub-linear in the number of input line segments.
- Flexible Input - Any kind of polygonal data can be processed, including polygons with an arbitrary depth of overlap
The FORSE engine incorporates a flexible and powerful design which supports carrying out all of the following operations:
- Overlay of Polygons and Lines
- Union of Polygons and Lines
- Line segment noding
- Line segment dissolve
- Noding validation
- Polygonization