How to define geometric modifiers

[plepe]

PGMapCSS could change the geometric representation of an object, e.g.:

• draw a buffer around the object
• draw a line through the current point which is parallel to a nearby object
• find a point inside a polygon for labeling

The main question is: how to define this alteration in the CSS file:

1) Treat geometry as property which is already pre-defined.

node[place=city] {
  geo: eval(buffer(prop(geo), 10px));
}

Not bad, but might be confusing (my favorite right now).

2) Treat geo as tag of the object

node[place=city] {
  set geo=eval(buffer(tag(geo), 10px));
}

This would change the geometry for all pseudo elements, which might not be desired.

3) Special syntax, e.g.

node[place=city] {
  geo(eval(buffer(geo, 10px))); 
}

I would be interested in your thoughts on this subject.

[plepe]

I decided to use variant 1. It has already been added in v0.2.0.