I'm trying to display text on a Windows control, rotated by 90 degrees, so that it reads from 'bottom to top' so to speak; basically it's the label on the Y axis of a graph.
I got my text to display vertically by changing my coordinate system for the DC by using SetGraphicsMode(GM_ADVANCED) and then using
XFORM transform;
const double angle = 90 * (boost::math::constants::pi<double>() / 180);
transform.eM11 = (FLOAT)cos(angle);
transform.eM12 = (FLOAT)(-sin(angle));
transform.eM21 = (FLOAT)sin(angle);
transform.eM22 = (FLOAT)cos(angle);
transform.eDx = 0.0;
transform.eDy = 0.0;
dc.SetWorldTransform(&transform);
Now when I run my program, the rotated text looks different from the same text when it's shown 'normally' (horizontally). I've tried with a fixed-width (system) font and the default WinXP font. The system font comes out look anti-aliased and the other one looks almost as if it's being drawn in a 1-pixel smaller font than the horizontal version, although they are drawn using the same DC and with no font changes in between. It looks as if Windows detects that I'm drawing a font not along the normal (0 degrees) axis and that it's trying to 'optimize' by anti-aliasing.
Now I don't want any of that. I just want to same text that I draw horizontally to be drawn exactly the same, except 90 degrees rotated, which is possible since it's a rotation of exactly 90 degrees. Does anyone know what's going on and whether I can change this easily to work as I want? I'd hate to have gone through all this trouble and finding up that I will have to resort to rendering to an off-screen bitmap, rotating it using a simple pixel-by-pixel rotation and having to bitblt that into my control :(