Is Cocoa animator proxy unable to handle 0.5 points?

Question

I'm trying to move the origin of a custom view. If I directly set the new origin for the frame, everything is working fine as expected.

[MyView setFrameOrigin:NSMakePoint(0.5, 0.5)];

If I try to animate the movement with the proxy animator.

[[MyView animator] setFrameOrigin:NSMakePoint(0.5, 0.5)];

The new origin will be (1, 1) instead of (0.5, 0.5). Am I doing something wrong? Is animator unable to handle 0.5 points?

Answer 1

My guess is the animator proxy is helpfully correcting a frame that would result in blurry edges and/or text. Drawing things across pixel borders (0.5, 0.5 vs. 1.0, 1.0 or 0.0, 0.0) is rarely useful unless you're trying to make something blurry (like a shadow, or glow).

You may very well have a good reason for doing this, but it's probably best to ask "why?"