OpenLayers 3 custom tileSize

Question

I want to change tileSize from default 256 to 512. I am using WMS version 1.1.0 so i cannot add WIDTH and HEIGHT parameters directly to source.

There are some examples where custom tileGrid is created where we can specify tileSize. In my case it is working only if i know the resolutions

var tileGrid = new ol.tilegrid.TileGrid({
    origin:ol.extent.getTopLeft(projectionExtent),
    resolutions:resolutions,
    tileSize :512
});

How to handle case when i use default resolutions (i do not specify them in view). Is there a way to retrieve the resolutions for projection before creating map? Or is there a better way to handle this kind of situation?

Answer 1

Instead of your own answer, I'd suggest

var projection = ol.proj.get('EPSG:900913');
var tileGrid = ol.tilegrid.createXYZ({
  extent: projection.getExtent(),
  tileSize: 512
});

If you are using other projections than the ones built into OpenLayers, you need to use the projection's validity extent for the extent option that you pass to ol.tilegrid.createXYZ. You can find that extent e.g. under "projected bounds" on http://epsg.io/.

Answer 2

I found the solution. To generate tileGrid for projection i used method createForProjection (not documented in api) and then replaced tileSize attribute in the tileGrid:

var projection = ol.proj.get('EPSG:900913');
var tileGrid = ol.tilegrid.createForProjection(projection);
tileGrid.tileSize_ = 512;

It is working. I will test if it does not break anything else.