do you have GDI+ turned on?
do you have Antialias set to false? (if so, set it to true)
OSX and Windows may not look Identical, but should be very similar…
Another thing… are you using a Font that may not be available on Windows? if so, then it is choosing something for you, and it may not be the best choice…
All things to consider,before blaming Xojo or Windows
Another way to go is to draw at four times the size of the canvas on a picture, and then draw a scaled down version of that picture onto the canvas. That should alleviate possible jaggies.
Yeah dont draw at 4x and scale down
You lose details and they get all munged together when you do this
Its why Apple recommends so many sizes for icons etc as you can tweak the nearest size much better & end up with a sharper look overall
You ask if GDI+ is turned on. How does this affect Windows? When I turn it on all my charts look terrible and increase in size, but when I turn it off, everything looks great.