Re: [groff] Now online: gropdf / grops previewer

[Ralph Corderoy]

Hi John,

> https://rawgit.com/Alhadis/Roff.js/web-demo/index.html
...
>    - *Some fonts may look different.* Browsers handle font-rendering,
>    which means the base 35 PDF fonts won't be visible in the renderer
>    unless they've also been installed in your system's usual fonts
>    directory.

Am I right in understanding your Javascript asks the <canvas> widget to
render some text in a particular font, size, and location, and what
pixels are set, e.g. for anti-aliasing, are up to the browser's
implementation?

>    If you zoom in using the *100%* menu, you'll notice you can't
>    scroll left or upwards. That's because the page contents extend
>    past the top-left corner of the browser window, and we all know you
>    can't scroll past the window's origin corner.

Someone else already mentioned the probable area to look in, but
https://stackoverflow.com/questions/11332608/understanding-html-5-canvas-scale-and-translate-order
may also be useful if you're not used to affine transformations for 2D
graphics.  If you can multiply a 3×1 matrix by a 3×3 matrix then you
should be able to figure it out.
https://www.willamette.edu/~gorr/classes/GeneralGraphics/Transforms/transforms2d.htm
looks like a reasonable intro from a quick skim.

-- 
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy