How to display small bitmaps as overlays?

If your image is in the same projection as your map, then...

Listen for zoom, pan and extent change events. Position your image using the top left location and the result of map.locationPoint. Scale your image using the ratio between the the projected side length and the original side length.

Off the top of my head (this code hasn't been compiled or tested) it would look something like:



// when you've loaded the image, before scaling it

var originalWidth:Number = img.width;
var originalHeight:Number = img.height;

var topLeftLocation:Location = new Location(...);
var bottomRightLocation:Location = new Location(...);

// then in map events ...

var topLeft:Point = map.locationPoint(topLeftLocation);
var bottomRight:Point = map.locationPoint(bottomRightLocation);

img.x = topLeft.x;
img.y = topLeft.y;

image.scaleX = (bottomRight.x - topLeft.x) / originalWidth;
image.scaleY = (bottomRight.y - topLeft.y) / originalHeight;



You can add the img as a child of Map directly, or you can make a separate Sprite or MovieClip to contain multiple image overlays.

Hope that helps!