This was implemented in https://sourceforge.net/p/tikiwiki/code/62324/
We want this for the web (https://en.wikipedia.org/wiki/Retina_Display) and for print (where we need higher resolution than on a screen) -> https://mpdf.github.io/reference/mpdf-variables/img-dpi.html
- https://css-tricks.com/responsive-images-youre-just-changing-resolutions-use-srcset/
- https://www.smashingmagazine.com/2014/05/responsive-images-done-right-guide-picture-srcset/
How should this be done in Tiki?
File Galleries x and y params
Tiki has the functions to downsize the images on the server in File Galleries. Then in the srcset it could just use the same file calls with the param &x=123
added and Tiki would serve the downsized version. Hopefully it is still working after some latest fixes...
It seems like that would work. I played around with the img plugin and was able to get it to return the following in the html by adding the parameter widths="600 1000 1400 2000":
<img srcset="tiki-download_file.php?fileId=1&display&x=600 600w, tiki-download_file.php?fileId=1&display&x=1000 1000w, tiki-download_file.php?fileId=1&display&x=1400 1400w, tiki-download_file.php?fileId=1&display&x=2000 2000w" sizes="50%" src="tiki-download_file.php?fileId=1&display" alt="Prez01" class="regImage img-responsive pluginImg1">
So this was working. As you grew the screen, the browser would request the larger sizes and they would get displayed.