Drawing a single point takes inordinate amount of time

[crschmidt]

The following chunk of GML takes a huge amount of time to render. It seems that the drawCircle function in Renderer.SVG is taking this time:

drawCircle: function(node, geometry, radius) {

node.setAttributeNS(null, "cx", geometry.x); node.setAttributeNS(null, "cy", geometry.y); node.setAttributeNS(null, "r", radius);

},

commenting out the 'r' setAttribute causes the layer to load quickly, but to not show anything (since it has no radius).

I don't get it.

<?xml version='1.0' encoding="utf-8" ?>
<wfs:FeatureCollection
   xmlns:ms="http://mapserver.gis.umn.edu/mapserver"
   xmlns:wfs="http://www.opengis.net/wfs"
   xmlns:gml="http://www.opengis.net/gml"
    >
    <gml:featureMember>
      <ms:PointsOfInterest>
        <ms:msGeometry>
        <gml:Point srsName="EPSG:4326">
          <gml:coordinates>3.059317, 36.768121 </gml:coordinates>
        </gml:Point>
        </ms:msGeometry>
      </ms:PointsOfInterest>
    </gml:featureMember>
</wfs:FeatureCollection>

[tschaub]

I assume this is the problem experienced here  http://www.nabble.com/Drawing-a-Point-Feature-in-Firefox-is-Slow-tf3468483.html

I think this is a bug at best - perhaps a blocker for 2.4.

[sderle]

we can't seem to reproduce this bug? some one please reopen this with a concrete use case that triggers the bug, if at all poss.

[crschmidt]

So, I can reliably reproduce this bug in Firefox. However, Neither Webkit Nightlies nor Opera demonstrate this bug, which lead me to believing it's a bug in Firefox's SVG implementation.

[crschmidt]

Firefox's SVG renderer can't reliably draw points beyond a certain scale. (Because of the way our SVG support currently works, the coordinates are geoegraphic, and it appears the very small circle radius breaks Firefox).

The fix to this is essentially to turn the geo-space into pixel space, thus removing the need for very-tiny points. This is similar to the change made to the VML renderer.

I'm going to start working on this now.

[crschmidt]

• Change coordinate space to be pixel based.
• Redraw nodes totally on every 'reprojectNode' call
• Make all x/y operations divided by resolution
• add getComponentsString, getShortString helpers

[crschmidt]

typo in drawCurve/drawSurface fixed in this patch

[sderle]

patch #2 looks good. please commit.

[crschmidt]

r2960