azavea/geotrellis — pull request #262 by lossyrob (2012-12-07 03:47:27+00:00)
Title: Focal Operations API refactor and optimizations

- Improved the FocalOp API.
- Allow for calling Cellwise or Cursor strategies based on neighborhood type.
- Allow for the indirection calculation of Hillshade through Aspect and Slope operations.
- Created a SurfacePointCalculation that allows better sharing of code between slope,aspect, and hillshade calculations.
- Use trigonometric identities to avoid calling out to any trig functions in Hillshade calculation (much faster).
- Moved Aspect and Slope into their own files.

Fixes #257