mapnik/mapnik — pull request #909 by zerebubuth (2011-10-12 00:12:52+00:00)
Title: Exposed the label collision detector

this exposes the label collision detector (4!?) via python and adds a new render_with_detector function to allow the detector to be passed into the rendering process which means you can keep the detector between render invocations. possible uses include clearing out areas of the map you know you'll want to render something in later (e.g: key / label / compass rose) or to get some layers as a separate image to be composited later. this patch only does this for the agg renderer, although it should be pretty simple to extend to the other renderers.