scale_max and scale_min in style rule do not work

[AM909]

If I understand it correctly, in a style rule, scale_max is supposed to set the max scale at which a particular rule will be used.

I set a custom icon for the highway=turning_circle rule, and set scale_max to 300 to prevent it from rendering at zoom levels more than 300m. However, it still renders at all zoom levels. I'm sure the rule is being applied, because it is rendering my custom icon.

Similarly, if I set scale_min to 100, there is still no change in behavior - the icon renders at all zoom levels.

[stoecker]

It does work, but the option to allow zoom level depending rendering is turned of by default.

[anonymous]

How do I turn it on?

[bastiK]

Set mappaint.zoomLevelDisplay=true in the advanced preferences.