SDL, sloped pixel lines

[SilverWarior]

But not always. If you draw a line then it's pixels are only scaled if that line ist either a horizontal or a vertical one. Sloped lines are rendered without pixel scaling.
That's because lines are rendered as rectangles internally:

Would you mind explaining of what you mean by "Sloped lines are rendered without pixel scaling"?
Perhaps by posting two example images. One showing sloped line with pixel scaling and one without.