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Modifying initResolutions so that minResolution and numZoomLevels are respected if they are set as layer options. Note that if only minResolution and maxResolution are specified, minResolution will still not be respected in general. r=pspencer (closes #1300)

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git-svn-id: http://svn.openlayers.org/trunk/openlayers@5918 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
This commit is contained in:
Tim Schaub
2008-01-28 16:28:21 +00:00
parent 866cfe631d
commit a14418f53f
2 changed files with 41 additions and 8 deletions
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31
lib/OpenLayers/Layer.js
View File

@@ -663,9 +663,7 @@ OpenLayers.Layer = OpenLayers.Class({
} else {
//maxResolution and numZoomLevels based calculation
confProps.resolutions = [];
// determine maxResolution
if (confProps.minScale) {
confProps.maxResolution =
@@ -691,8 +689,9 @@ OpenLayers.Layer = OpenLayers.Class({
confProps.minResolution = Math.max(wRes, hRes);
}
// determine numZoomLevels
if (confProps.minResolution != null) {
// determine numZoomLevels if not already set on the layer
if (confProps.minResolution != null &&
this.options.numZoomLevels == undefined) {
var ratio = confProps.maxResolution / confProps.minResolution;
confProps.numZoomLevels =
Math.floor(Math.log(ratio) / Math.log(2)) + 1;
@@ -700,10 +699,26 @@ OpenLayers.Layer = OpenLayers.Class({
// now we have numZoomLevels and maxResolution,
// we can populate the resolutions array
confProps.resolutions = new Array(confProps.numZoomLevels);
var base = 2;
if(typeof confProps.minResolution == "number" &&
this.options.numZoomLevels > 1) {
/**
* If numZoomLevels is explicitly set in the layer options,
* respect it. If numZoomLevels is not specified, we use
* exponential scaling with a base of 2. If numZoomLevels
* is specified, we use exponential scaling and determine the
* appropriate base so minResolution is reached.
*/
base = Math.pow(
(confProps.maxResolution / confProps.minResolution),
(1 / (confProps.numZoomLevels - 1))
);
}
for (var i=0; i < confProps.numZoomLevels; i++) {
var res = confProps.maxResolution / Math.pow(2, i);
confProps.resolutions.push(res);
}
var res = confProps.maxResolution / Math.pow(base, i);
confProps.resolutions[i] = res;
}
}
//sort resolutions array ascendingly

18
tests/test_Layer.html
View File

@@ -118,6 +118,24 @@
t.eq(layer.maxResolution, maxResolution, "maxResolution set correctly");
t.eq(layer.numZoomLevels, numZoomLevels, "numZoomLevels set correctly");
}
function test_Layer_initResolutions(t) {
t.plan(3);
var map = new OpenLayers.Map("map");
var options = {
minResolution: 1,
maxResolution: 10,
numZoomLevels: 5
};
var layer = new OpenLayers.Layer("test", options);
layer.map = map;
layer.initResolutions();
t.eq(layer.minResolution.toPrecision(9), (1).toPrecision(9),
"layer minResolution preserved");
t.eq(layer.maxResolution.toPrecision(9), (10).toPrecision(9),
"layer maxResolution preserved");
t.eq(layer.numZoomLevels, 5, "layer numZoomLevels preserved");
}
function test_05_Layer_visibility(t) {