OL Mapview: provided boundaries are not used........why?

Question

When I supply the leftbottom and righttop coordinates for mapview these are not exactly used. The resulting difference is pretty big. What am I missing?!

Bounds = [-0.6688232421875, 49.78322566351028, 11.6688232421875, 54.35032343193191];
Bounds = ol.proj.transformExtent(Bounds, ol.proj.get('EPSG:4326'), ol.proj.get('EPSG:3857'));


var map = new ol.Map({
    target: 'map',
    view: new ol.View({
        projection: "EPSG:3857"
        })
    });

map.getView().fit(Bounds,map.getSize());

The mapview gets new ('larger') bounds, but not the above ones. The 'new' bounds are [-6.837646484374999,47.32226629045806,17.837646484375,56.461134011735425]

How can I get the map to stick to the provided ones??

EDIT: I have adjusted the code based on comments from Mike (thx!!). ** What is the best way to achieve what I want......i.e. display part of the map that is within a boundingbox that has the above leftbottom and righttop (LON/LAT) coordinates? **

Since OpenLayers 3 extent is used to constrain the center of the view, it's not the same as bounds in OpenLayers 2. The extent to which the map can be panned will be twice the width and height of the extent property, and more at low zoom levels. — Mike, Dec 05 '18 at 10:32
The correct syntax of bounding extent is `Bounds = ol.extent.boundingExtent([[-0.6688232421875, 49.78322566351028], [11.6688232421875, 54.35032343193191]]);` or you could simply use `Bounds = [-0.6688232421875, 49.78322566351028, 11.6688232421875, 54.35032343193191];` Also `.fit()` should be called after the map is declared, it doesn't return a value. — Mike, Dec 05 '18 at 10:33

score 1 · Accepted Answer · answered Dec 05 '18 at 16:54

The bounds are being used but unless you specify constrainResolution: false the view will snap to the closest integer zoom level. This code demonstrates getting an exact fit by allowing a fractional zoom level. Note that if the map width/height ratio doesn't match the extent there will be some excess coverage

Bounds = [-0.6688232421875, 49.78322566351028, 11.6688232421875, 54.35032343193191];
Bounds = ol.proj.transformExtent(Bounds, ol.proj.get('EPSG:4326'), ol.proj.get('EPSG:3857'));

var map = new ol.Map({
    target: 'map',
    layers: [
        new ol.layer.Tile({
            source: new ol.source.OSM()
        }),
        new ol.layer.Vector({
            source: new ol.source.Vector({
                features: [new ol.Feature(ol.geom.Polygon.fromExtent(Bounds))]
            })
        })
    ]
});
map.getView().fit(Bounds, {size: map.getSize(), constrainResolution: false});

OL Mapview: provided boundaries are not used........why?

1 Answers1