[mapguide-users] Mapping lat long to screen x y coordinates

[julienltr]

julienltr wrote:
> 
> I know that AJAX viewer use the JavaScript function "ScreenToMapUnits" to
> translate screen coordinates to map's but I can't find a reverse
> function...
> 

I finally find a solution myself. Because we have a ScreenToMapUnits
function in ajaxmappane.templ, it's very easy to do some math to get a
MapUnitsToScreen function :

function MapUnitsToScreen(x, y)
{
xScr = parseInt( (x - extX1) * mapDevW / (extX2 - extX1) );
yScr = parseInt( (y - extY1) * mapDevH / (- extY1 + extY2) );
	
if(xScr > mapDevW - 1) xScr = mapDevW - 1;
else if(xScr < 0) xScr = 0;

if(yScr > mapDevH - 1) yScr = mapDevH - 1;
else if(yScr < 0) y = 0;

return new Point(xScr, yScr);
} 

Problem solved ;)
-- 
View this message in context: http://www.nabble.com/Mapping-lat-long-to-screen-x-y-coordinates-tf4028110s16610.html#a12537083
Sent from the MapGuide Users mailing list archive at Nabble.com.