FW: [ka-Map-users] Overlay image

[jochen at IngenieurTeam2.com]

Hello Brent,
this is unfortunately not the problem, my problem is that the scale of
ka-map don't matches the scale of my image. Besides that the redrawfunction
has to be called whenever the extent of ka-map changes, even if you're
panning.

Thanks,
jochen


________________________________

From: Brent Pedersen [mailto:bpederse at gmail.com]
Sent: Donnerstag, 29. September 2005 18:36
To: Grefe, Jochen
Cc: ka-map-users at lists.maptools.org
Subject: Re: [ka-Map-users] Overlay image


hi, if i understand correctly
if you overlay your own image, it is static and you must do
myKaMap.registerForEvent(KAMAP_SCALE_CHANGED,this,redrawFunction)

in order to get a new image on zoom in/out. where redrawFunction has to
remove current image, and resend the request for a new image given the  new
extents
-brent


On 9/29/05, jochen at ingenieurteam2.com <jochen at ingenieurteam2.com > wrote: 

	Hello ka-map user,
	
	I want to highlight polygons on the map (based on a query). 
	To do this (and perhaps other things) I want to render an image
	with the size of the viewport which contains the visible part of the
map.
	And then overlay this image over the viewport.
	This works as I suppose but I have problem with the scale. 
	It seems like there is a fractor missing. But which?
	
	Best regards,
	Jochen
	
	
	//overlay.js start
	function jg (oKaMap)
	{
	this.kaMap = oKaMap;
	this.highlight = jg_highlight;
	this.drawOverlay = jg_drawOverlay;
	}
	
	function jg_highlight()
	{
	var px = this.kaMap.getGeoExtents();
	var url = this.kaMap.server + "/overlay.php";
	url += "?map=" + this.kaMap.currentMap;
	url += "&width=" + this.kaMap.viewportWidth;
	url += "&height=" + this.kaMap.viewportHeight;
	url += "&minx=" + px[0];
	url += "&miny=" + px[1];
	url += "&maxx=" + px[2];
	url += "&maxy=" + px[3];
	call(url, this, this.drawOverlay);
	}
	
	function jg_drawOverlay (szResult)
	{
	eval( szResult );
	var canvas = myKaMap.createDrawingCanvas( 500 );
	var img = document.createElement ( 'img' );
	img.src = this.imgSrc;
	img.style.width = this.kaMap.viewportWidth + "px";
	img.style.height = this.kaMap.viewportHeight + "px";
	this.kaMap.addObjectGeo(canvas, this.imgX, this.imgY , img );
	}
	//overlay.js start
	
	//overlay.php start
	<?php
	dl('php_mapscript_46.dll');
	
	$width  = $_REQUEST['width'];
	$height = $_REQUEST['height'];
	$minx = $_REQUEST['minx'];
	$miny = $_REQUEST['miny']; 
	$maxx = $_REQUEST['maxx'];
	$maxy = $_REQUEST['maxy'];
	
	$map = ms_newMapObj("c:/path/file.map"); // the same mapfile like
ka-map
	shows
	$map->outputformat->set("transparent", MS_ON ); 
	$l1 = $map->getLayerByName ("L1");
	$l1 -> set("status", MS_OFF);
	$l2 = $map->getLayerByName ("L2");
	$l2 -> set("status", MS_OFF);
	$l3 = $map->getLayerByName ("L3"); 
	$c3 = $l3 -> getClass (0);
	$style = ms_newStyleObj($c3);
	$style->color->setRGB(255,0,0); // simulate highlighting
	$map -> setExtent ($minx, $miny, $maxx, $maxy);
	$map -> setSize   ($width, $height); 
	$image=$map->draw();
	$image_url=$image->saveWebImage();
	$szResult = "this.imgSrc = '".$image_url."';";
	$szResult .= "this.imgX = ".$minx.";";
	$szResult .= " this.imgY = ".$maxy.";";
	echo $szResult;
	?>
	//overlay.php end
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