forZoomlevel method
Creates a copy of itself with the data needed for the given zoomlevel. Note that this should only be called from Rendertheme and NOT from RenderthemeZoomlevel
Implementation
@override
RenderinstructionHillshading forZoomlevel(int zoomlevel, int level) {
RenderinstructionHillshading renderinstruction = RenderinstructionHillshading(level)
..renderinstructionScale(this, zoomlevel)
..baseSrcMixinScale(this, zoomlevel);
renderinstruction.always = always;
renderinstruction.layer = layer;
renderinstruction.minZoom = minZoom;
renderinstruction.maxZoom = maxZoom;
renderinstruction.magnitude = magnitude;
return renderinstruction;
}