John Femiani wrote:
Count me as interested in any attempt at a free generic geometry library.
Is this purely 'rectilinear' -- I mean, when you say polygons do you mean any kind of polygon or only the kinds of polygons formed by the union of axis-aligned rectangles? Could I find the intersection of a star and a triangle?
Gyuszi Suto wrote:
The polygons need to be formed by union of axis-aligned rectangles, yes. In addition to that, GTL supports 45 degree polygons as well. Can GTL intersect a star and a triangle? If both are limited to rectilinear or 45 degreee edges, yes, otherwise no.
There is the strong possibility that I will be extending the GTL capabilities beyond 45 degree to allow arbitrary angles with the goal of providing best in class performance with a generic and productive interface. As we are all aware, this leads to the need to provide a mechanism to ensure numerical robustness at considerable cost in runtime. That mechanism would obviously include a generic interface for specifying the internal numerical data type to be used by the algorithm, with a default provided by the library. However, our intention is not to provide a comprehensive geometry library, which would be too broad in scope, but rather a starting point for generic geometry that the community can participate in and extend in the most useful directions. In looking at the recent submissions to boost related to geometry there is a fair amount of overlap with our library, particularly in what I call the basic types such as point2d. The ideal outcome from my point of view is that we all benefit from a synthesis of ideas and craft a boost geometry library together that goes beyond the code we will initially submit and will continue to be enhanced and extended with the participation of the community over time. Lucanus Simonson