openstreetmap-website/public/javascripts/tile.js
2006-07-28 21:53:30 +00:00

889 lines
26 KiB
JavaScript

// June 20th 2005 http://civicactions.net anselm@hook.org public domain version 0.5
//
// miscellaneous
//
var netscape = ( document.getElementById && !document.all ) || document.layers;
var defaultEngine = null; // xxx for firefox keyboard events.
var PI = 3.14159265358979323846;
var lat_range = PI, lon_range = PI;
//
// Utility - get div position - may not be accurate
//
function getCSSPositionX(parent)
{
var offset = parent.x ? parseInt(parent.x) : 0;
offset += parent.style.left ? parseInt(parent.style.left) : 0;
for(var node = parent; node ; node = node.offsetParent )
{
offset += node.offsetLeft;
}
return offset;
}
function getCSSPositionY(parent)
{
var offset = parent.y ? parseInt(parent.y) : 0;
offset += parent.style.top ? parseInt(parent.style.top) : 0;
for(var node = parent; node ; node = node.offsetParent )
{
offset += node.offsetTop;
}
return offset;
}
///
/// initialize a new tile engine object
/// usage: var engine = new tile_engine_new(parentdiv,stylehints,wmssource,lon,lat,zoom,optional width, optional height)
///
function tile_engine_new(parentname,hints,feedurl,url,lon,lat,zoom,w,h)
{
// NW geocoder removed for now
this.timestamp = new Date().getTime();
this.urlAttr = new Array();
// NW Removed navigation buttons entirely for flexibility
this.lonPerPixel = function()
{ return (this.lon_quant/this.scale)/this.tilewidth; }
this.latPerPixel = function()
{ return (this.lat_quant/this.scale)/this.tileheight; }
this.xToLon = function(x)
{ return this.lon + (x-this.thewidth/2)*this.lonPerPixel(); }
this.yToLat = function(y)
{ return normallat(this.lat - (y-this.theheight/2)
*this.latPerPixel()); }
this.lonToX = function (lon)
{ return ((lon-this.lon)/this.lonPerPixel()) + this.thewidth/2;}
this.latToY = function(lat)
{ return ((this.lat-mercatorlat(lat))/this.latPerPixel()) +
this.theheight/2; }
//
// it is possible that this collection is already in use - clean it
//
this.clean = function()
{
/*
while( this.parent.hasChildNodes() )
this.parent.removeChild( this.parent.firstChild );
*/
for(var ct=0; ct<this.parent.childNodes.length; ct++)
{
if(this.parent.childNodes[ct].id != "controls")
this.parent.removeChild(this.parent.childNodes[ct]);
}
//
// build inner tile container for theoretical speed improvement?
// center in parent for simplicity of math
// size of inner container is irrelevant since overflow is enabled
//
if( this.dragcontainer )
{
this.tiles = document.createElement('div');
this.tiles.style.position = 'absolute';
this.tiles.style.left = this.displaywidth/2 + 'px';
this.tiles.style.top = this.displayheight/2 + 'px';
this.tiles.style.width = '16px';
this.tiles.style.height = '16px';
if( this.debug )
{
this.tiles.style.border = 'dashed green 1px';
}
this.tiles.tile_engine = this;
this.parent.appendChild(this.tiles);
}
else
{
this.tiles = this.parent;
}
}
/// focus over specified lon/lat and zoom
/// user should call this.drag(0,0) after this to force an initial refresh
///
this.performzoom = function(lon,lat,z)
{
// setup for zoom
// this engine operates at * scale to try avoid tile errors thrashing
// server cache
this.scale = 1000000;
this.lon_min_clamp = -180 * this.scale;
this.lon_max_clamp = 180 * this.scale;
this.lat_min_clamp = -180 * this.scale; //t
this.lat_max_clamp = 180 * this.scale; //t
this.lon_start_tile = 180 * this.scale;
this.lat_start_tile = 90 * this.scale; //t
this.zoom_power = 2;
this.lon_quant = this.lon_start_tile;
this.lat_quant = this.lat_start_tile;
this.lon = lon;
this.lat = lat;
// operational lat - = lat due to quirks in our engine and quirks in o
// lon/lat design
lat = -lat;
// divide tile size until reach requested zoom
// trying to guarantee consistency so as to not thrash the server side tile cache
while(z > 0)
{
this.lon_quant = this.lon_quant / this.zoom_power;
this.lat_quant = this.lat_quant / this.zoom_power;
z--;
}
this.lon_quant = Math.round( this.lon_quant );
this.lat_quant = Math.round( this.lat_quant );
// get user requested exact lon/lat
this.lon_scaled = Math.round( lon * this.scale );
this.lat_scaled = Math.round( lat * this.scale );
// convert requested exact lon/lat to quantized lon lat (rounding down
// or up as best suits)
this.lon_round = Math.round( this.lon_scaled / this.lon_quant ) *
this.lon_quant;
this.lat_round = Math.round( this.lat_scaled / this.lat_quant ) *
this.lat_quant;
//alert('lon_round=' + this.lon_round+ ' lat_round='+this.lat_round);
// calculate world extents [ this is the span of all tiles in lon/lat ]
this.lon_min = this.lon_round - this.lon_quant;
this.lon_max = this.lon_round + this.lon_quant;
this.lat_min = this.lat_round - this.lat_quant;
this.lat_max = this.lat_round + this.lat_quant;
// set tiled region details [ this is the span of all tiles in pixels ]
this.centerx = 0;
this.centery = 0;
this.tilewidth = 256;
this.tileheight = 128;
this.left = -this.tilewidth;
this.right = this.tilewidth;
this.top = -this.tileheight;
this.bot = this.tileheight;
// adjust the current center position slightly to reflect exact lat/lon
// not rounded
this.centerx -= (this.lon_scaled-this.lon_round)/
(this.lon_max-this.lon_min)*(this.right-this.left);
this.centery -= (this.lat_scaled-this.lat_round)/
(this.lat_max-this.lat_min)*(this.bot-this.top);
}
this.update_perma_link = function() {
// because we're using mercator
updatelinks(this.lon,normallat(this.lat),this.zoom);
}
///
/// draw the spanning lon/lat range
/// drag is simply the mouse delta in pixels
///
this.drag = function(dragx,dragy)
{
var fred=true;
// move the drag offset
this.centerx += dragx;
this.centery += dragy;
// update where we think the user is actually focused
this.lon = ( this.lon_round - ( this.lon_max - this.lon_min ) /
( this.right - this.left ) * this.centerx ) / this.scale;
this.lat = - ( this.lat_round - ( this.lat_max - this.lat_min ) /
( this.bot - this.top ) * this.centery ) / this.scale;
this.update_perma_link();
// show it
var helper = this.navhelp;
// extend exposed sections
var dirty = false;
while( this.left + this.centerx > -this.displaywidth/2 &&
this.lon_min > this.lon_min_clamp )
{
this.left -= this.tilewidth;
this.lon_min -= this.lon_quant;
dirty = true;
}
while( this.right + this.centerx < this.displaywidth/2 &&
this.lon_max < this.lon_max_clamp )
{
this.right += this.tilewidth;
this.lon_max += this.lon_quant;
dirty = true;
}
while( this.top + this.centery > -this.displayheight/2 &&
this.lat_min > this.lat_min_clamp )
{
this.top -= this.tileheight;
this.lat_min -= this.lat_quant;
dirty = true;
}
while( this.bot + this.centery < this.displayheight/2 &&
this.lat_max < this.lat_max_clamp )
{
this.bot += this.tileheight;
this.lat_max += this.lat_quant;
dirty = true;
}
// prepare to walk the container and assure that all nodes are correct
var containerx;
var containery;
// in drag container mode we do not have to move the children all the
// time
if( this.dragcontainer )
{
this.tiles.style.left = this.displaywidth / 2 + this.centerx + 'px';
this.tiles.style.top = this.displayheight / 2 + this.centery + 'px';
if( !dirty && this.tiles.hasChildNodes() )
{
return;
}
containerx = this.left;
containery = this.top;
}
else
{
containerx = this.left + this.centerx;
containery = this.top + this.centery;
}
// walk all tiles and repair as needed
// xxx one bug is that it walks the _entire_ width and height...
// not just visible.
// xxx this makes cleanup harder and perhaps a bitmap is better
var removehidden = 1;
var removecolumn = 0;
var removerow = 0;
var containeryreset = containery;
for( var x = this.lon_min; x < this.lon_max ; x+= this.lon_quant )
{
// will this row be visible in the next round?
if( removehidden )
{
var rx = containerx + this.centerx;
if( rx > this.displaywidth / 2 )
{
removerow = 1;
// ideally i would truncate max width here
}
else if( rx + this.tilewidth < - this.displaywidth / 2 )
{
removerow = 1;
}
else
{
removerow = 0;
}
}
for( var y = this.lat_min; y < this.lat_max ; y+= this.lat_quant )
{
// is this column visible?
if( removehidden )
{
var ry = containery + this.centery;
if( ry > this.displayheight / 2 )
{
removecolumn = 1;
}
else if( ry + this.tileheight < - this.displayheight/2)
{
removecolumn = 1;
}
else
{
removecolumn = 0;
}
}
// convert to WMS compliant coordinate system
var lt = x / this.scale;
var rt = lt + this.lon_quant / this.scale;
var tp = y / this.scale;
var bt = tp + this.lat_quant / this.scale;
var temp = bt;
var bt = -tp;
var tp = -temp;
// modify for mercator-projected tiles:
tp = 180/PI * (2 * Math.atan(Math.exp(tp * PI / 180)) - PI / 2);
bt = 180/PI * (2 * Math.atan(Math.exp(bt * PI / 180)) - PI / 2);
// make a key
var key = this.url + "?WIDTH="+(this.tilewidth)+"&HEIGHT="+
(this.tileheight)+"&BBOX="+lt+","+tp+","+rt+","+bt;
// see if our tile is already present
var node = document.getElementById(key);
// create if not present
if(!node)
{
if( this.debug > 0)
{
node = document.createElement('div');
}
else
{
node = document.createElement('img');
}
node.id = key;
node.className = 'tile';
node.style.position = 'absolute';
node.style.width = this.tilewidth + 'px';
node.style.height = this.tileheight + 'px';
node.style.left = containerx + 'px';
node.style.top = containery + 'px';
node.style.zIndex = 10; // to appear under the rss elements
node.tile_engine = this;
if( this.debug > 0)
{
node.style.border = "1px solid yellow";
node.innerHTML = key;
if( this.debug > 1 )
{
var img = document.createElement('img');
img.src = key;
node.appendChild(img);
}
}
var goURL = key + "&zoom=" + this.zoom;
for(var k in this.urlAttr)
{
goURL += "&"+k+"="+this.urlAttr[k];
}
node.src = goURL;
node.alt = "loading tile..";
node.style.color = "#ffffff";
this.tiles.appendChild(node);
}
// adjust if using active style
else if( !this.dragcontainer ) {
node.style.left = containerx + 'px';
node.style.top = containery + 'px';
}
containery += this.tileheight;
}
containery = containeryreset;
containerx += this.tilewidth;
}
}
this.zoomTo = function(zoom)
{
this.zoom = zoom;
if (this.zoom < this.minzoom) { this.zoom = this.minzoom; }
if (this.zoom > this.maxzoom) { this.zoom = this.maxzoom; }
///
/// immediately draw and or fit to feed
///
this.performzoom(this.lon,this.lat,zoom);
this.drag(0,0);
///
} // CLOSE ZOOM FUNCTION
this.setLatLon = function(lat,lon)
{
this.lon=lon;
this.lat=mercatorlat(lat);
this.clean();
this.performzoom(lon,mercatorlat(lat),this.zoom);
this.drag(0,0);
}
this.forceRefresh = function()
{
this.clean();
this.performzoom(this.lon,this.lat,this.zoom);
this.drag(0,0);
}
///
/// zoom a tile group
///
this.tile_engine_zoomout = function()
{
this.clean();
this.zoomTo(this.zoom-1);
return false; // or safari falls over
}
///
/// zoom a tile group
///
this.tile_engine_zoomin = function()
{
this.clean();
this.zoomTo(this.zoom+1);
return false; // or safari falls over
}
this.setURL=function(url) { this.url=url; }
///
/// intercept context events to minimize out-of-browser interruptions
///
this.event_context = function(e)
{
return false;
}
///
/// keys
///
this.event_key = function(e)
{
var key = 0;
var hostengine = defaultEngine;
if( window && window.event && window.event.srcElement ) {
hostengine = window.event.srcElement.tile_engine;
} else if( e.target ) {
hostengine = e.target.tile_engine;
} else if( e.srcElement ) {
hostengine = e.srcElement.tile_engine;
}
if( hostengine == null ) {
hostengine = defaultEngine;
if( hostengine == null ) {
return;
}
}
if( e == null && document.all ) {
e = window.event;
}
if( e ) {
if( e.keyCode ) {
key = e.keyCode;
}
else if( e.which ) {
key = e.which;
}
switch(key) {
case 97: // a = left
hostengine.drag(16,0);
break;
case 100: // d = right
hostengine.drag(-16,0);
break;
case 119: // w = up
hostengine.drag(0,16);
break;
case 120: // x = dn
hostengine.drag(0,-16);
break;
case 115: // s = center
new tile_engine_new(hostengine.parentname,
"FULL",
hostengine.feedurl, // xxx hrm, cache this?
hostengine.url,
hostengine.lon,
hostengine.lat,
hostengine.zoom,
0,0
);
break;
case 122: // z = zoom
new tile_engine_new(hostengine.parentname,
"FULL",
hostengine.feedurl, // xxx hrm, cache this?
hostengine.url,
hostengine.lon,
hostengine.lat,
hostengine.zoom + 1,
0,0
);
break;
case 99: // c = unzoom
new tile_engine_new(hostengine.parentname,
"FULL",
hostengine.feedurl, // xxx hrm, cache this?
hostengine.url,
hostengine.lon,
hostengine.lat,
hostengine.zoom - 1,
0,0
);
break;
}
}
}
///
/// catch mouse move events
/// this routine _must_ return false or else the operating system outside-of-browser-scope drag and drop handler will interfere
///
this.event_mouse_move = function(e) {
var hostengine = null;
if( window && window.event && window.event.srcElement ) {
hostengine = window.event.srcElement.tile_engine;
} else if( e.target ) {
hostengine = e.target.tile_engine;
} else if( e.srcElement ) {
hostengine = e.srcElement.tile_engine;
}
if( hostengine && hostengine.drag ) {
if( hostengine.mousedown ) {
if( netscape ) {
hostengine.mousex = parseInt(e.pageX) + 0.0;
hostengine.mousey = parseInt(e.pageY) + 0.0;
} else {
hostengine.mousex = parseInt(window.event.clientX) + 0.0;
hostengine.mousey = parseInt(window.event.clientY) + 0.0;
}
hostengine.drag(hostengine.mousex-hostengine.lastmousex,hostengine.mousey-hostengine.lastmousey);
}
hostengine.lastmousex = hostengine.mousex;
hostengine.lastmousey = hostengine.mousey;
}
// must return false to prevent operating system drag and drop from handling events
return false;
}
///
/// catch mouse down
///
this.event_mouse_down = function(e) {
var hostengine = null;
if( window && window.event && window.event.srcElement ) {
hostengine = window.event.srcElement.tile_engine;
} else if( e.target ) {
hostengine = e.target.tile_engine;
} else if( e.srcElement ) {
hostengine = e.srcElement.tile_engine;
}
if( hostengine ) {
if( netscape ) {
hostengine.mousex = parseInt(e.pageX) + 0.0;
hostengine.mousey = parseInt(e.pageY) + 0.0;
} else {
hostengine.mousex = parseInt(window.event.clientX) + 0.0;
hostengine.mousey = parseInt(window.event.clientY) + 0.0;
}
hostengine.lastmousex = hostengine.mousex;
hostengine.lastmousey = hostengine.mousey;
hostengine.mousedown = 1;
}
// must return false to prevent operating system drag and drop from handling events
return false;
}
///
/// catch double click (use to center map)
///
this.event_double_click = function(e) {
var hostengine = null;
if( window && window.event && window.event.srcElement ) {
hostengine = window.event.srcElement.tile_engine;
} else if( e.target ) {
hostengine = e.target.tile_engine;
} else if( e.srcElement ) {
hostengine = e.srcElement.tile_engine;
}
if( hostengine ) {
if( netscape ) {
hostengine.mousex = parseInt(e.pageX) + 0.0;
hostengine.mousey = parseInt(e.pageY) + 0.0;
} else {
hostengine.mousex = parseInt(window.event.clientX) + 0.0;
hostengine.mousey = parseInt(window.event.clientY) + 0.0;
}
var dx = hostengine.mousex-(hostengine.displaywidth/2)-hostengine.parent_x;
var dy = hostengine.mousey-(hostengine.displayheight/2)-hostengine.parent_y;
hostengine.drag(-dx,-dy); // TODO smooth
}
// must return false to prevent operating system drag and drop from handling events
return false;
}
///
/// catch mouse up
///
this.event_mouse_up = function(e) {
var hostengine = null;
if( window && window.event && window.event.srcElement ) {
hostengine = window.event.srcElement.tile_engine;
} else if( e.target ) {
hostengine = e.target.tile_engine;
} else if( e.srcElement ) {
hostengine = e.srcElement.tile_engine;
}
if( hostengine ) {
if( netscape ) {
hostengine.mousex = parseInt(e.pageX) + 0.0;
hostengine.mousey = parseInt(e.pageY) + 0.0;
} else {
hostengine.mousex = parseInt(window.event.clientX) + 0.0;
hostengine.mousey = parseInt(window.event.clientY) + 0.0;
}
hostengine.mousedown = 0;
}
// must return false to prevent operating system drag and drop from handling events
return false;
}
///
/// catch mouse out
///
this.event_mouse_out = function(e) {
var hostengine = null;
if( window && window.event && window.event.srcElement ) {
hostengine = window.event.srcElement.tile_engine;
} else if( e.target ) {
hostengine = e.target.tile_engine;
} else if( e.srcElement ) {
hostengine = e.srcElement.tile_engine;
}
if( hostengine ) {
if( netscape ) {
hostengine.mousex = parseInt(e.pageX) + 0.0;
hostengine.mousey = parseInt(e.pageY) + 0.0;
} else {
hostengine.mousex = parseInt(window.event.clientX) + 0.0;
hostengine.mousey = parseInt(window.event.clientY) + 0.0;
}
hostengine.mousedown = 0;
}
// must return false to prevent operating system drag and drop from handling events
return false;
}
///
/// register new handlers to catch desired events
///
// NW removed parameter - always use parent
this.event_catch = function() {
this.parent.style.cursor = 'move';
if( netscape ) {
window.captureEvents(Event.MOUSEMOVE);
window.captureEvents(Event.KEYPRESS);
}
this.parent.onmousemove = this.event_mouse_move;
this.parent.onmousedown = this.event_mouse_down;
this.parent.onmouseup = this.event_mouse_up;
this.parent.onkeypress = this.event_key;
window.ondblclick = this.event_double_click;
if( window ) {
window.onmousemove = this.event_mouse_move;
window.onmouseup = this.event_mouse_up;
window.ondblclick = this.event_double_click;
}
}
this.setURLAttribute = function(k,v)
{
this.urlAttr[k] = v;
}
this.getURLAttribute = function(k)
{
return this.urlAttr[k];
}
this.getDownloadedTileBounds = function()
{
var bounds = new Array();
bounds.w=this.lon_min;
bounds.s=normallat(this.lat_min);
bounds.e=this.lon_max;
bounds.n=normallat(this.lat_max);
return bounds;
}
this.getVisibleBounds = function()
{
var bounds = new Array();
bounds.w = this.xToLon(0);
bounds.s = this.yToLat(this.theheight);
bounds.e = this.xToLon(this.thewidth);
bounds.n = this.yToLat(0);
return bounds;
}
// navout and navin stuff - START
// draw navigation buttons into the parent div
// ENTRY CODE BEGINS HERE....
// get parent div or fail
this.parent = document.getElementById(parentname);
if( this.parent == null ) {
alert('The tile map engine cannot find a parent container named ['
+parentname+']');
return;
}
//
// store for later
//
this.parentname = parentname;
this.hints = hints;
this.feedurl = feedurl;
this.url = url;
this.lon = lon;
this.lat = mercatorlat(lat);
this.thewidth = w;
this.theheight = h;
this.dragcontainer = 1;
this.debug = 0;
// for firefox keyboard
defaultEngine = this;
document.engine = this;
//
// decide on display width and height
//
if( !w || !h )
{
w = parseInt(this.parent.style.width);
h = parseInt(this.parent.style.height);
if(!w || !h)
{
w = 512;
h = 256;
this.parent.style.width = w + 'px';
this.parent.style.height = h + 'px';
}
}
else
{
this.parent.style.width = parseInt(w) + 'px';
this.parent.style.height = parseInt(h) + 'px';
}
this.displaywidth = w;
this.displayheight = h;
this.minzoom = 0;
this.maxzoom = 20;
//
// enforce parent div style?
// position absolute is really only required for firefox
// http://www.quirksmode.org/js/findpos.html
//
this.parent_x = getCSSPositionX(this.parent);
this.parent_y = getCSSPositionY(this.parent);
this.parent.style.position = 'relative';
this.parent.style.overflow = 'hidden';
this.parent.style.backgroundColor = '#000036';
// attach event capture parent div
this.event_catch();
this.clean();
//this.makeZoom();
this.zoomTo(zoom);
}
function normallat(mercatorlat)
{
var tp = 180/PI*(2 * Math.atan(Math.exp(mercatorlat * PI / 180)) - PI / 2);
return tp;
}
function mercatorlat(normallat)
{
var lpi = 3.14159265358979323846;
return Math.log( Math.tan( (lpi / 4.0) + (normallat / 180.0 * lpi / 2.0))) *
180.0 / lpi ;
}