Symbolizer that specifies rendering of a tiff, png or svg image as a directional marker.
Can be used as an alternative to a PointSymbolizer to give more control over positioning of the image.
Configuration Options
| Name | Description | Default | Applies to SVG |
|---|---|---|---|
| allow-overlap | Allow the symbolizer to overlap others. | false | yes |
| spacing | Distance between markers in pixels. | 100 | yes |
| max-error | Maximum amount the marker can be move from its designated place to avoid collisions. This value is a fraction of "spacing", e.g. spacing = 100, max_error = 0.2 then the maximum the marker can be moved is 20pixels, if this is not enough it isn't drawn at all. | 0.2 | yes |
| file | The SVG file to use for the marker | built-in marker | yes |
| transform | SVG transform | identity | yes |
| opacity | Opacity | 1.0 | yes |
| fill | Color of the marker fill, e.g. #FFFFFF. | blue | no |
| stroke | CSS colour - A Color value such as 'green' or #A3D979 | black | no |
| stroke-width | 0.0 - n - Width of outline in pixels | 1.0 | no |
| stroke-opacity | 0.0 - 1.0 - 1 is fully opaque while zero is fully transparent and .5 would be 50% transparent | 1.0 | no |
| width | width of marker pixels | 10 | no |
| height | height of marker in pixels | 10 | no |
| placement | "point", "interior", "line", "vertex-first" (mapnik >= 3), "vertex-last" (mapnik >= 3) | line (mapnik <=2.0.x) point (mapnik >= 2.1) | no (todo) |
| ignore-placement | "true" or "false" | "false" | no (todo) |
| marker-type | "arrow" "ellipse" | "arrow" if line placement, "ellipse" if point placement | no |
It can be added to a Rule with line features like:
<MarkersSymbolizer />
The MarkersSymbolizer should draw blue directional arrows in the direction of the geometry (for things like one-way streets).
In case you notice arrows pointing the wrong direction, this means that the segment has been coded in the wrong way.
The ST_reverse function of Postgis can fix this (The problem will then be to identify the geometries that need to be updated).
SVG markers
NEW: Starting from r1793 MarkersSymbolizer supports Scalable Vector Graphics (SVG) as input images:
<MarkersSymbolizer spacing="100" file="/Users/artem/Desktop/svg/ladybird.svg" transform="translate(0 -16) scale(2.0)"/>
Dynamic Ellipses
NEW: Starting from r2158 MarkersSymbolizer supports width/height/fill/stroke properties to dynamically draw circles (w == h) or ellipses (w != h) when no SVG file is supplied:
<MarkersSymbolizer fill="darkorange" opacity=".7" width="20" height="10" stroke="orange" stroke-width="7" stroke-opacity=".2" placement="point" marker-type="ellipse"/>
CAVEAT: these properties do not apply to SVG files, and SVG transforms are not supported for modifying ellipses (yet).
OSM currently renders one-way street arrows with Mapnik using several stacked instances of [LineSymbolizer] with varying dash-arrays, but could potentially use the MarkersSymbolizer in the future:
<LinePatternSymbolizer file="/home/mapnik/mapnik/symbols/arrow.png" type="png" width="74" height="8" />