7 ms·

This just makes me angry. The whole point of being able to specify in px was to have something that is actually specific to the device's pixels---otherwise you

by blahedo 16y ago

This just makes me angry. The whole point of being able to specify in px was to have something that is actually specific to the device's pixels---otherwise you'd use points or inches or cm---for those rare instances where the pixel count is actually relevant. Of course, it got overused, but the answer should not be to just redefine "pixel" as "something a bit smaller than a point" (except in a bit more detail)! Argh.

imd 16y ago
I may be reading it wrong, but it sounds like a px is a pixel—until you zoom in. If you define a web page’s default font size as 12px, and it stayed at that no matter how much you zoomed in, it wouldn’t be much of a zoom feature, would it?
- blahedo 16y ago
  That would be reasonable, but the CSS standard says: "If the pixel density of the output device is very different from that of a typical computer display, the user agent should rescale pixel values." It then goes on to define a "reference pixel" in terms of arclength subtended within the user's field of vision. On reflection, I suppose this is sufficiently different from pt/in/cm (which measure absolute length) to merit its own separate measure; I just wish they hadn't used the term "pixel" for it. Because "pixel" already means something else and the arclength subtended by a pixel in a "typical computer display" has changed considerably over the last twenty years.
j-g-faustus 16y ago
Actually, rescaling pixels is part of the CSS specification: If the pixel density of the output device is very different from that of a typical computer display, the user agent should rescale pixel values. [...] It is recommended that the reference pixel be [...] one pixel on a device with a pixel density of 96dpi http://www.w3.org/TR/CSS21/syndata.html#length-units http://www.w3.org/TR/CSS21/syndata.html#length-units

by blahedo 16y ago

imd 16y ago

I may be reading it wrong, but it sounds like a px is a pixel—until you zoom in. If you define a web page’s default font size as 12px, and it stayed at that no matter how much you zoomed in, it wouldn’t be much of a zoom feature, would it?

blahedo 16y ago
That would be reasonable, but the CSS standard says: "If the pixel density of the output device is very different from that of a typical computer display, the user agent should rescale pixel values." It then goes on to define a "reference pixel" in terms of arclength subtended within the user's field of vision. On reflection, I suppose this is sufficiently different from pt/in/cm (which measure absolute length) to merit its own separate measure; I just wish they hadn't used the term "pixel" for it. Because "pixel" already means something else and the arclength subtended by a pixel in a "typical computer display" has changed considerably over the last twenty years.

j-g-faustus 16y ago

Actually, rescaling pixels is part of the CSS specification: If the pixel density of the output device is very different from that of a typical computer display, the user agent should rescale pixel values. [...] It is recommended that the reference pixel be [...] one pixel on a device with a pixel density of 96dpi http://www.w3.org/TR/CSS21/syndata.html#length-units http://www.w3.org/TR/CSS21/syndata.html#length-units