I'm the author of the blog post. I just used sprite positioning as a simple example. Things like collision detection and physics can't be done with half pixels.
Trying to read between the lines here, if your objection is to half-pixels because they’re not precise enough for (good) physics, then I apologize for being unclear - I mean half-pixels, or quarter-pixels, or eighth-pixels, or whatever.
Another way of wording my comment is that I think it’s easier - especially for beginners - to think in terms of smaller units (represented as integers) than in terms of a new number format for representing fixed-size fractional parts of larger units. But the two concepts are ultimately the same.
But that's basically what fixed point is, no? Half pixels is fixed point with a single bit for decimals. Quarter pixels is two bits, and so on. I think the disadvantage is you now have to think in a strange unit that isn't intuitive. For my game I tend to think in screen sizes for things. Thinking in screen size*factor would be harder I think. Fixed point is basically just doing that for me and hiding the details really.
To be fair, rereading the post I realize I did make it sound like you would only need this for positioning sprites. I'll see about rewording it.
Or maybe we're both talking about the same thing and you're taking a different approach. That is fair too.
Yeah, we're technically talking about the same thing - just a different way of thinking about it.
When I was learning retro game dev (mostly Game Boy), I found fixed point very intimidating. Reading stuff like "the player will move at 1.5 pixels per frame, and to store the decimal point we'll use this special format where certain bits represent the fractional part and certain bits represent the integer part" scared the heck out of me when I was still, like, coming to grips with binary representations at all.
Whereas "the player will move at 3 half-pixels per frame" is just a really straightforward conceptualization. The data representation is the same, the code to convert from half-pixels to pixels is the same, but one way of understanding it feels very technical and abstract.
Especially when working in assembly language (like I was), where you don't really have any kind of typing mechanism, it never really made sense to build a fixed-point data type abstraction.
And, to be clear, I'm not trying to give you, specifically, any guff for this; it's as fine an article on fixed-point that there is.
