LÖVE

I found that when drawing text will have dirty pixels.

Is this due to unaligned pixels? How can if fixes this?

I have fixed the none rotated case by force translation align to pixel.

But the rotated case can't be fixed yet...

Do you mean that what you do not like about the text is the anti-aliasing and you want non-antialiased text? Sadly I honestly do not know how to do it, but my guess would be setting some filter to nearest instead of linear.