Osmarender/svg open09

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Notes for presentation at SVG Open 2009

30,000ft Overview

osmarender takes stylesheet, filters data through rules and outputs SVG. close-areas.pl, lines2curves for pre/post-processing.

Then Tiles@Home, distributed rendering platform, clients run the transformation and rasterizes to PNG tiles.

Bugs and issues

  • Too hard to do changes across zoom levels, we probably need a meta-stylesheet.

Challenges

Architecture

  • XSL implementation compared to perl version

Rendering

Both use incredible amounts of memory/other resources, 4GB T@H client dies every now and then due to OOM. Note that this is why we need a whole distributed architecture with several hundred clients to do rendering.

T@H, and especially the SVG::Rasterize module, is a study in Batik and Inkscape bugs.

  • Inkscape
    • Brittle, handles failures badly
      • Corrupting preferences bug
      • Windows version pops modal dialogue
    • Doesn't seem to return the same return codes for various failures across versions or platforms
  • Batik

History