discard tiles outside zoom when rebuilding
discard tiles outside zoom when rebuilding

rosamcgee/tangram,TitoAgudelo/tangram,xvilan/tangram,rosamcgee/tangram,zerebubuth/tangram,ceseale/tangram,zerebubuth/tangram,zerebubuth/tangram,DHaylock/tangram,TitoAgudelo/tangram,xvilan/tangram,taylorhxu/tangram,DHaylock/tangram,xvilan/tangram,ceseale/tangram,taylorhxu/tangram,TitoAgudelo/tangram,ceseale/tangram,rosamcgee/tangram,DHaylock/tangram,tangrams/tangram,tangrams/tangram,taylorhxu/tangram