Add ol.TileGrid.getZForResolution

2012-07-08 12:37:22 +02:00
parent 391b5906bc
commit 40acb70a3c
2 changed files with 59 additions and 0 deletions
@@ -259,6 +259,30 @@ ol.TileGrid.prototype.getTileCoordResolution = function(tileCoord) {
 };


+/**
+ * @param {number} resolution Resolution.
+ * @return {number} Z.
+ */
+ol.TileGrid.prototype.getZForResolution = function(resolution) {
+  var z;
+  for (z = 0; z < this.numResolutions_; ++z) {
+    if (this.resolutions_[z] == resolution) {
+      return z;
+    } else if (this.resolutions_[z] < resolution) {
+      if (z === 0) {
+        return z;
+      } else if (resolution - this.resolutions_[z] <=
+          this.resolutions_[z - 1] - resolution) {
+        return z;
+      } else {
+        return z - 1;
+      }
+    }
+  }
+  return this.numResolutions_ - 1;
+};
+
+
 /**
 * @param {ol.TileCoord} tileCoord Tile coordinate.
 * @param {function(number, ol.TileBounds): boolean} callback Callback.