Map coordinates to screen space?

DavidElies

Does anybody know how to map geographical coordinates and distances to screen coordinates in pixels?  I want to draw graphics at a size that correspond to actual distances on Earth.  For example, a 1km grid square.  It sure seems like it should be easy...but I can't figure it out.

Thanks!

DavidElies

Thanks, Dan.  I was able to adapt your code for my purposes.  Instead of using a Polygon, I just used an Extent since I was looking for a square anyway.  This simplified the process a bit:

protected function Map_mapClickHandler(event:MapMouseEvent):void
   {
    //allow user to enter size of square desired in map units
    if(tInput1.text == ""){
         Alert.show("Please enter a number in the text input before clicking the map.");
    }else{
     
     var size:int = Number(tInput1.text);
     var halfSize:Number = size/2;
     
     var center:MapPoint=Map.toMapFromStage(event.stageX, event.stageY);
     
     var extent:Extent = new Extent(center.x - halfSize,
               center.y - halfSize,
               center.x + halfSize,
               center.y + halfSize,
               map.spatialReference);
     
     var newGraphic:Graphic = new Graphic;
     newGraphic.geometry=extent;
     newGraphic.symbol=symbol1;
     
     gLayer.add(newGraphic);
    }
   }

This appears to be working for me.  Thanks again!  If anybody else has another idea, I'd still like to hear it.