While upgrading to 1481 from 1347, I came across a problem with my google tile generator producing renderings with missing features (Canada was missing) at the highest levels (0-4). Essentially I was building a level 0 tile, 256x256px, with a 128px buffer with the 'world' map. The change introduced in trunk version 1348 was causing the projection of the buffer extents to the layer extents to produce bad values (pr_transform was returning a good return code) and as a result, some of the polygons were being omitted from the rendering.
The map srs was "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgri...@null +wktext +no_defs" and the layer srs was "+proj=merc +lon_0=0 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs" There are a number of ways this can be solved outside of mapnik, which I have done, but I thought I should pass this on in case others have come across it. This may be an issue for anyone who is using buffered rendering near or on the edges of proj4 ability to transform correctly since the values used for the buffer extents may be well outside reasonable values. Best regards, Dave _______________________________________________ Mapnik-devel mailing list Mapnik-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/mapnik-devel
