developmentseed/node-blend — pull request #24 by springmeyer (2012-12-08 00:18:16+00:00)
Title: Faster quantize

I think this work should land in master node-blend and go into its own release (tinting will come next).

This speeds up quantization overall, for hextree (quite a bit), for fixed palettes, and a slight bit for all quantizing due to using pod (plain old data) for the hashmap key instead of a custom class.

This brings in `sparehash/dense_hash_map` as the default hashmap, but has configure options and environment settings to force going back to `std::tr1::unordered_map`.

See mapnik/mapnik#1629 for motivations behind this work.