font.SetRotation combined with DrawString with BPoint positions cause confusion

[pulkomandy]

I am trying to change FontDemo to use a single DrawString call to draw the whole string. There is a version of DrawString which takes an array of BPoints, I expect that it would work similarly to calling DrawString multiple times with one character at a time and separate points.

It appears that this is not the case when the font has been rotated using font.SetRotation. The passed points are transformed in some way, and as a result, the characters are not drawing at the expected place.