When labeling a curved line in QGIS 2.2, and setting Placement to 'Curved', the behavior of 'maximum angle between curved characters' is not intuitive, and I haven't been able to find documentation on it.
The line I'm trying to label is pretty jagged (it's a hiking trail). If I leave the 'maximum angle' settings both at 20 (default), no label is drawn. If I crank the values up to 45, the label is drawn but it is very jagged just like the trail, and illegible. If I crank the values down to 30, the label disappears again.
So, it seems like these values are being interpreted like so: "If any generated character would be more than x degrees rotated from the previous character, then do not draw the label."
Whereas I was hoping the values would be used as a sort of filter / smoothing algorithm: "Rotate the characters as needed such that each character's rotation is within x degrees of the adjacent characters' rotations."
Can anyone provide a more clear interpretation?