3 ms·

Is a desktop screen different than a phone screen? In the physical world, 1/96 inch is 1/96 inch. The notion of HiDPI abstracts for the fact that their pixel pi

Is a desktop screen different than a phone screen? In the physical world, 1/96 inch is 1/96 inch. The notion of HiDPI abstracts for the fact that their pixel pitch is much finer than a typical display, usually by 2-4x. Otherwise, most displays fudge for the fact that they're not quite 96ppi, since 100 or 94 isn't vastly different. Anyways, this is a good thing. It shouldn't really adjust with screen growth, but it's important to note that it's an abstract dimension (so thinking in terms of PPI/DPI with CSS pixels is unwise). It allows you to be agnostic to devices, and respect the user's preference (if possible) for how close to the physical display they are.

milankragujevic 7y ago
100 ppi for a Full HD 22" screen. 386 ppi for a Full HD 5.7" screen (i.e. my phone).
marcosdumay 7y ago
> Is a desktop screen different than a phone screen? Hum... Yes. That's the entire point of my comment. One is 90cm away, the other is 150cm away. An arcsecond of viewport on one is almost half of the linear size of the same viewport size on the other.
- c-smile 7y ago
  There is an abbreviation for that - YMMV, right? My monitor is closer to that usually. And that's the point. It makes absolutely no sense to measure viewing angles. The only thing that we can agree is that area of finger/screen touch measured on screen surface is roughly equal for humans - 1cm x 1cm or something like that. So size of your buttons shall be measured in units of screen surface, but not in some mysterious things that depend on distance orthogonal to screen surface. So 1. CSS pixels must be treated as logical length unit equal 1/96 inch, and, 2. Browsers must ensure that 1in or 10cm are exactly that when measured by physical ruler on screen surface. I, as a developer, must know that my 1cm button is exactly that on screen and so human clickable.
  - marcosdumay 7y ago
    Your mileage will vary. A lot. But CSS sizes are defined by viewing angles, not by linear size. There was plenty of debate at the time it was standardized, and really, none of the options is good so they got one of the bad ones.
    - c-smile 7y ago
      Yep, initial idea of HTML as just one dimensional tape of scrollable text - something that has given width but no height - literally just a Text for reading ... Who would have thought that we will start clicking <button>s by literally fingers. But how much of dev time wasted already in discovering that `px` stands for points in MacOS terms (1/72 on inch initially and now 1/96 of inch) and nothing near real pixels ...

milankragujevic 7y ago

100 ppi for a Full HD 22" screen. 386 ppi for a Full HD 5.7" screen (i.e. my phone).

marcosdumay 7y ago

> Is a desktop screen different than a phone screen? Hum... Yes. That's the entire point of my comment. One is 90cm away, the other is 150cm away. An arcsecond of viewport on one is almost half of the linear size of the same viewport size on the other.

c-smile 7y ago
There is an abbreviation for that - YMMV, right? My monitor is closer to that usually. And that's the point. It makes absolutely no sense to measure viewing angles. The only thing that we can agree is that area of finger/screen touch measured on screen surface is roughly equal for humans - 1cm x 1cm or something like that. So size of your buttons shall be measured in units of screen surface, but not in some mysterious things that depend on distance orthogonal to screen surface. So 1. CSS pixels must be treated as logical length unit equal 1/96 inch, and, 2. Browsers must ensure that 1in or 10cm are exactly that when measured by physical ruler on screen surface. I, as a developer, must know that my 1cm button is exactly that on screen and so human clickable.
- marcosdumay 7y ago
  Your mileage will vary. A lot. But CSS sizes are defined by viewing angles, not by linear size. There was plenty of debate at the time it was standardized, and really, none of the options is good so they got one of the bad ones.
  - c-smile 7y ago
    Yep, initial idea of HTML as just one dimensional tape of scrollable text - something that has given width but no height - literally just a Text for reading ... Who would have thought that we will start clicking <button>s by literally fingers. But how much of dev time wasted already in discovering that `px` stands for points in MacOS terms (1/72 on inch initially and now 1/96 of inch) and nothing near real pixels ...