5 ms·

I agree that it's a sensible behavior -- I've always wondered why the 'px' unit even exists if it scales just like everything else. That said, what does the CSS

by gxti 16y ago

I agree that it's a sensible behavior -- I've always wondered why the 'px' unit even exists if it scales just like everything else. That said, what does the CSS standard say?

endtime 16y ago
Would browser zoom be under the purview of the CSS standard?
- gxti 16y ago
  Do you mean zoom, or changing font size? Because zoom scales everything, images included. Scaling affects only text, and ideally, things that are sized relative to the text (but not pixels).
blahedo 16y ago
It's a little complicated and (I'd argue) mildly broken[1], but roughly, 'in', 'cm', and 'pt' all refer to real-world distance measurements; 'em', 'en', and 'ex' refer to sizes relative to the font size; 'px' is a modified real-world measure that scales with distance[2]; and there is nothing at all that refers to actual, honest-to-god pixels. Scaling 'px' during a zoom is no more standards-violating than scaling 'in' etc. during a zoom. [1]Because 'px' doesn't refer to pixels. [2]It refers to a unit that scales according to display resolution and usual distance from eye; essentially it's a measure of the angle subtended on your retina. This is useful because (in theory) 1px will look "the same size" (and be about as legible) on a mobile phone, on a laptop, on a desktop, or on a projector, whereas 1in or 1pt(=1/72in) will appear much smaller if further away. What 1px is not, however, is a "pixel".
- seabee 16y ago
  Now comes the question: if 'px' isn't it, is there any unit that corresponds 1:1 with a bitmapped image?
  - wmf 16y ago
    At default zoom level, 1 px should be 1 pixel except on "retina" displays where it is 2 pixels or printers where it is 3-5 dots. http://webkit.org/blog/55/high-dpi-web-sites/ http://webkit.org/blog/55/high-dpi-web-sites/ http://www.w3.org/TR/CSS21/syndata.html#length-units http://www.w3.org/TR/CSS21/syndata.html#length-units
  - pornel 16y ago
    Yes, px. Bitmaps should be scaled from device pixels to CSS pixels.

by gxti 16y ago

I agree that it's a sensible behavior -- I've always wondered why the 'px' unit even exists if it scales just like everything else. That said, what does the CSS standard say?

endtime 16y ago

Would browser zoom be under the purview of the CSS standard?

gxti 16y ago
Do you mean zoom, or changing font size? Because zoom scales everything, images included. Scaling affects only text, and ideally, things that are sized relative to the text (but not pixels).

blahedo 16y ago

It's a little complicated and (I'd argue) mildly broken[1], but roughly, 'in', 'cm', and 'pt' all refer to real-world distance measurements; 'em', 'en', and 'ex' refer to sizes relative to the font size; 'px' is a modified real-world measure that scales with distance[2]; and there is nothing at all that refers to actual, honest-to-god pixels. Scaling 'px' during a zoom is no more standards-violating than scaling 'in' etc. during a zoom. [1]Because 'px' doesn't refer to pixels. [2]It refers to a unit that scales according to display resolution and usual distance from eye; essentially it's a measure of the angle subtended on your retina. This is useful because (in theory) 1px will look "the same size" (and be about as legible) on a mobile phone, on a laptop, on a desktop, or on a projector, whereas 1in or 1pt(=1/72in) will appear much smaller if further away. What 1px is not, however, is a "pixel".

seabee 16y ago
Now comes the question: if 'px' isn't it, is there any unit that corresponds 1:1 with a bitmapped image?
- wmf 16y ago
  At default zoom level, 1 px should be 1 pixel except on "retina" displays where it is 2 pixels or printers where it is 3-5 dots. http://webkit.org/blog/55/high-dpi-web-sites/ http://webkit.org/blog/55/high-dpi-web-sites/ http://www.w3.org/TR/CSS21/syndata.html#length-units http://www.w3.org/TR/CSS21/syndata.html#length-units
- pornel 16y ago
  Yes, px. Bitmaps should be scaled from device pixels to CSS pixels.