LogalDeveloper/Minecraft-Overviewer
Archived
0
Fork 0
Code Activity

more accurate marker positioning on map, and a reasonable custom projection

Browse Source
This commit is contained in:
Aaron Griffith
2010-09-27 14:54:10 -04:00
parent aa82a82f13
commit a5cc2e3ae2
1 changed files with 92 additions and 70 deletions
Download Patch File Download Diff File Expand all files Collapse all files

150
template.html
View File

@@ -22,6 +22,65 @@
debug: false
};
// our custom projection maps Latitude to Y, and Longitude to X as normal,
// but it maps the range [0.0, 1.0] to [0, tileSize] in both directions
// so it is easier to position markers, etc. based on their position
// (find their position in the lowest-zoom image, and divide by tileSize)
function MCMapProjection() {
this.inverseTileSize = 1.0 / config.tileSize;
}
MCMapProjection.prototype.fromLatLngToPoint = function(latLng) {
var x = latLng.lng() * config.tileSize;
var y = latLng.lat() * config.tileSize;
return new google.maps.Point(x, y);
};
MCMapProjection.prototype.fromPointToLatLng = function(point) {
var lng = point.x * this.inverseTileSize;
var lat = point.y * this.inverseTileSize;
return new google.maps.LatLng(lat, lng);
};
// helper to get map LatLng from world coordinates
// takes arguments in X, Y, Z order
// (arguments are *out of order*, because within the function we use
// the axes like the rest of Minecraft Overviewer -- with the Z and Y
// flipped from normal minecraft usage.)
function fromWorldToLatLng(x, z, y)
{
// the width and height of all the highest-zoom tiles combined, inverted
var perPixel = 1.0 / (config.tileSize * Math.pow(2, config.maxZoom));
// This information about where the center column is may change with a different
// drawing implementation -- check it again after any drawing overhauls!
// point (0, 0, 127) is at (0.5, 0.0) of tile (tiles/2 - 1, tiles/2)
// so the Y coordinate is at 0.5, and the X is at 0.5 - ((tileSize / 2) / (tileSize * 2^maxZoom))
// or equivalently, 0.5 - (1 / 2^(maxZoom + 1))
var lng = 0.5 - (1.0 / Math.pow(2, config.maxZoom + 1));
var lat = 0.5;
// the following metrics mimic those in ChunkRenderer.chunk_render in "chunk.py"
// each block on X axis adds 12px to x and subtracts 6px from y
lng += 12 * x * perPixel;
lat -= 6 * x * perPixel;
// each block on Y axis adds 12px to x and adds 6px to y
lng += 12 * y * perPixel;
lat += 6 * y * perPixel;
// each block down along Z adds 12px to y
lat += 12 * (128 - z) * perPixel;
// add on 12 px to the X coordinate and 18px to the Y to center our point
lng += 12 * perPixel;
lat += 18 * perPixel;
return new google.maps.LatLng(lat, lng);
}
var MCMapOptions = {
getTileUrl: function(tile, zoom) {
var url = config.path;
@@ -52,6 +111,7 @@
var MCMapType = new google.maps.ImageMapType(MCMapOptions);
MCMapType.name = "MC Map";
MCMapType.alt = "Minecraft Map";
MCMapType.projection = new MCMapProjection();
function CoordMapType() {
}
@@ -75,61 +135,30 @@
};
var map;
var prot;
var markersInit = false;
function convertCoords (x,y,z) {
var imgx = 0;
var imgy = 0;
imgx = imgx + (12*x);
imgy = imgy - (6*x);
imgx = imgx + (12 * y);
imgy = imgy + (6* y);
imgy = imgy - (12*z);
// this math is mysterious. i don't fully understand it
// but the idea is to assume that block 0,0,0 in chunk 0,0
// is drawn in the very middle of the gmap at (192,192)
return [192*Math.pow(2,config.maxZoom)+imgx, 192*Math.pow(2,config.maxZoom)+imgy+768+768];
}
function initMarkers() {
if (markersInit) { return; }
if (markersInit) { return; }
markersInit = true;
markersInit = true;
prot = map.getProjection();
for (i in markerData) {
var item = markerData[i];
for (i in markerData) {
var item = markerData[i];
var converted = convertCoords(item.x-16, item.z, item.y);
var x = converted[0] / Math.pow(2, config.maxZoom);
var y = converted[1] / Math.pow(2, config.maxZoom);
var p = new google.maps.Point(x,y);
var marker = new google.maps.Marker({
position: prot.fromPointToLatLng(p),
map: map,
title:item.msg
});
}
}
var converted = fromWorldToLatLng(item.x, item.y, item.z);
var marker = new google.maps.Marker({
position: converted,
map: map,
title: item.msg
});
}
}
function initialize() {
var mapOptions = {
zoom: config.defaultZoom,
center: new google.maps.LatLng(-45, 90),
center: new google.maps.LatLng(0.5, 0.5),
navigationControl: true,
scaleControl: false,
mapTypeControl: false,
@@ -139,34 +168,27 @@ title:item.msg
if(config.debug) {
map.overlayMapTypes.insertAt(0, new CoordMapType(new google.maps.Size(config.tileSize, config.tileSize)));
google.maps.event.addListener(map, 'click', function(event) {
console.log("latLng; " + event.latLng.lat() + ", " + event.latLng.lng());
var pnt = map.getProjection().fromLatLngToPoint(event.latLng);
console.log("point: " + pnt);
var pxx = pnt.x * config.tileSize * Math.pow(2, config.maxZoom);
var pxy = pnt.y * config.tileSize * Math.pow(2, config.maxZoom);
console.log("pixel: " + pxx + ", " + pxy);
});
}
// Now attach the coordinate map type to the map's registry
map.mapTypes.set('mcmap', MCMapType);
// We can now set the map to use the 'coordinate' map type
map.setMapTypeId('mcmap');
prot = map.getProjection();
if (config.debug)
google.maps.event.addListener(map, 'click', function(event) {
console.log("latLng: " + event.latLng.lat() + ", " + event.latLng.lng());
var pnt = prot.fromLatLngToPoint(event.latLng);
console.log("point: " + pnt);//
var pxx = pnt.x * Math.pow(2,config.maxZoom);
var pxy = pnt.y * Math.pow(2,config.maxZoom);
console.log("pixel: " + pxx + ", " + pxy);
});
google.maps.event.addListener(map, 'projection_changed', function(event) {
initMarkers();
});
// initialize the markers
initMarkers();
}
</script>
</head>