[sorry for the repeated emails] On Tue, Nov 19, 2013 at 5:47 PM, Tab Atkins Jr. <[email protected]> wrote: > On Tue, Nov 19, 2013 at 2:22 PM, Tab Atkins Jr. <[email protected]> wrote: >> Using a url/size pair in src='' >> would be invalid if sizes='' wasn't specified. > > On second thought, this isn't necessary. You can always set <img > width>, or just let it take the default intrinsic width of 300px. > <picture sizes> would just override the intrinsic width of the <img>. > > After all, even if your image isn't variable-sized, using the url/size > syntax might still be easier than url/density, because you don't have > to do any math, or change the densities around when you change the > image size.
This means, then, that it's actually legitimate to mix url/density and url/size pairs, so we don't even need separate grammar clauses. The url/size pairs just get turned into url/[effective density] pairs, calculated from the intrinsic size (possibly modified by <img width> or <picture sizes>). This also means that you can use <picture sizes> and url/density together. None of these are particularly good ideas, mind you; I'm just saying that there's no real reason to disallow them, or prevent them from working with each other. The concepts are actually fairly independent in terms of operation. ~TJ
