Wide line symbols

Stephen Lime steve.lime at dnr.state.mn.us
Thu Nov 16 08:54:59 EST 2000


There is, even in 3.3.xxx. In the older versions you had to use ellipse symbols (which are scalable) and draw the layer twice to achieve this. In the CVS code I've added a series of "overlay..." parameters (e.g. OVERLAYCOLOR, OVERLAYSIZE, OVERLAYMAXSIZE...) that allow you to stack 2 symbols- which should cover the vast majority of uses. You still need to use ellipse symbols.

SYMBOL
  NAME 'circle'
  TYPE ELLIPSE
  FILLED
  POINTS 1 1 END
END

You can see the effect in this interface:

  http://maps.dnr.state.mn.us/landview/

Look a the roads layer. The mapfile can be viewed at:

  http://maps.dnr.state.mn.us/landview/view.map

If multiple classes need overlay symbols AND those classes can intersect then the current algorithm breaks down. In that case you need to bust the single shapefile into single, class specific files. The only way around that is pre-sort the shapes based on class and adapt the code to deal with it. (comming soon)

The CVS version also features the ability to define symbols within the mapfile. The example mapfile mentioned above also does that. For GIF/PNG symbols you can use the filename for the symbol (i.e. SYMBOL images/myimage.gif) and that will work too. That behavior is present in 3.3.011.

Steve

>>> "Berend  Veldkamp" <b.veldkamp at zonnet.nl> 11/16/00 06:01 AM >>>
List,
There must be an easier way to do this: Draw a white line 8 pixels wide
(or even wider) and a gray border (if I didn't make myself clear, see
attached file).
One way that works is: draw the same layer three times to do this, with
the following symbols:

# Right side of line
  style
    -4 0 0
    -3 0 0
    -2 0 0
    -1 0 0
    0 0 0
  end

# Left side of line
  style
    4 0 0
    3 0 0
    2 0 0
    1 0 0
  end

# Border
  type styled
  style
    -5 0 0
    5 0 0
  end

I tried to create a symbol of 8 pixels wide, but this one seems to draw
8 pixels on one side of the line instead of centered.
I found some messages in the archive that mentioned changes in the
symbol thing, what's the status of this?
Will it be possible to use (marker)symbols which aren't in the symbol
file? And scaled line symbols?

Berend

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