[Tilesathome] Using Batik to render tiles instead of Inkscape

[Brent Easton]

Due to the current issues with Inkscape, I have been investigating using Batik to render image tiles. The Batik distribution includes a utility rasterizer program to do just this. Had a few problems getting it running, but my findings so far are:


The job stream is generating illegal svg that Batik is choking on. Inkscape must be quietly ignoring the errors. So far:


1. CSS error in .untagged-segments in z12 and z13

            .untagged-segments {
                stroke-width: 0.5px;
                stroke-linejoin: round;
                stroke-linecap: butt;
                stroke: #e0e0e0;
                stroke-dasharray: 0.5,0.5;
            }

 'butt' is not a valid option for stroke-linejoin. should be round?  Will go away in Osmarender 6.

2. CSS error in .city_caption in z14

			.city-caption           { font-size: 14px; opacity: 50%; }

"50%" is not a valid option for opacity. Should be 0.5


3. Illegal descriptor in <Path> 

<path id="way_end_4981047" d="MM1441.97899999995 1048.96107085533L1441.97899999995 1048.96107085533"/>
<path id="way_normal_4981078" d="M 1182.88799999988 429.774486661176L1192.23699999992,469.054969928261L1201.58599999996,508.333043571463L1210.09699999973,544.088247139217"/>
<path id="way_start_4981078" d="M 1182.88799999988 429.774486661176L1187.80852631569,450.448425222799"/>

See the MM in the first line. I have not been able to work out why this is happening, but it is a more serious issue. Presumable Inkscape is just ignoring this as well.

This only occurs in some ways in some tiles. I got this on a motorway way on tile 3763 2458. There where 3 cases if 'MM'

For an acid test, I tried central Sydney (3768, 2458). After fixing the 580 occurences of 'MM' (changed to 'M '), the rasterizer happily rendered the z12 svg into a png tile in about 25 seconds, using a peak memory of 300Mb. If anything the output looks better than the Inkscape version.
Doing the same thing manually with Inkscape (open, then export) took several minutes and 550Mb of memory.

I believe this is looking very promising, It's sort of like using a can opener to open a can instead of a $100,000 industrial robot :)  

Can someone have a look at the 'MM' problem. It's sort of like using a can opener to open a can instead of a $100,000 industrial robot :) I had a look at Osmarender.xsl, but could not see how it can happen.

If we can solve this, I will try and do a full test implementation.

Cheers,
Brent.


____________________________________________________________
Brent Easton                       
Analyst/Programmer                               
University of Western Sydney                                   
Email: b.easton at uws.edu.au