artemp/mapnik — Issue #757: SVG transforms invalidate bbox used for placement
Author: artemp
Created: 2011-10-11 16:35:26+00:00
State: open
Labels: Core_Library

For example, in agg_renderer::process for point symbolizers the "label" extent is calculated (line 80) before the affine transform for the symbol is applied (line 86 ff). The result of this is that applying a transform="scale(10)" can lead to overlapping symbols, even if allow-overlap is set to false.

Further, the label extent is not used to clip the rendering of SVG symbols, and so often anti-aliasing "bleeds" outside the area that label_ext covers.