Method: drawFeature Draw the feature. The optional style argument can be used to override the feature's own style. This method should only be called from layer.drawFeature().
Parameters: feature - {<OpenLayers.Feature.Vector>} style - {
Returns: {Boolean} true if the feature has been drawn completely, false if not, undefined if the feature had no geometry
Method: eraseFeatures This is called by the layer to erase features
Parameters: features - {Array(<OpenLayers.Feature.Vector>)}
Method: eraseGeometry Remove a geometry from the renderer (by id). virtual function.
Parameters: geometry - {<OpenLayers.Geometry>} featureId - {String}
Method: getFeatureIdFromEvent Returns a feature id from an event on the renderer. How this happens is specific to the renderer. This should be called from layer.getFeatureFromEvent(). Virtual function.
Parameters: evt - {<OpenLayers.Event>}
Returns: {String} A feature id or undefined.
Method: getRenderLayerId Gets the layer that this renderer's output appears on. If moveRoot was used, this will be different from the id of the layer containing the features rendered by this renderer.
Returns: {String} the id of the output layer.
Method: moveRoot moves this renderer's root to a (different) renderer. To be implemented by subclasses that require a common renderer root for feature selection.
Parameters: renderer - {<OpenLayers.Renderer>} target renderer for the moved root
Method: removeText Function for removing text labels. This method is only called by the renderer itself.
Parameters: featureId - {String}
Method: setExtent Set the visible part of the layer.
Resolution has probably changed, so we nullify the resolution cache (this.resolution) -- this way it will be re-computed when next it is needed. We nullify the resolution cache (this.resolution) if resolutionChanged is set to true - this way it will be re-computed on the next getResolution() request.
Parameters: extent - {<OpenLayers.Bounds>} resolutionChanged - {Boolean}
Returns: {Boolean} true to notify the layer that the new extent does not exceed the coordinate range, and the features will not need to be redrawn. False otherwise.
Method: clear Clear all vectors from the renderer. virtual function.