If I'm going to use this as a means of generating bitmap icons at
large sizes, I want it to support all the same modes as the existing
bitmap script. So this adds a mode to the SVG generator that produces
the same black and white colour scheme as the existing monochrome
bitmap icons.
(Plus, who knows, the black and white SVGs might come in useful for
other purposes. Printing as a logo on black-and-white printers springs
to mind.)
The existing monochrome icons aren't greyscale: all colours are
literally either black or white, except for the cardboard box in the
installer icon, which is halftoned. Here I've rendered that box as
mid-grey. When I convert the rendered SVG output to an actual
1-bit (plus alpha) image, I'll have to redo that halftoning.
It looked nasty that the back corner of the monitor didn't line up
exactly with the outline of the system box behind it. Now I choose the
y offset between the two components to ensure it does. Also adjusted
the monitor's depth so that it fits better with the new alignment.
This gets us scalable icons that will go to extremely large sizes
without the problems that arise from scaling up the output of
mkicon.py, in which outlines become too thin because the script was
mostly concerned with trying to squeeze all the desired detail into
_tiny_ sizes.
The SVG icons are generated by mksvg.py, which is a conversion of the
existing mkicon.py. So the SVG files themselves are not committed in
this repo; 'make svg' in the icons subdir will generate them.
(I haven't decided yet whether this state of affairs should be
permanent. Perhaps _having_ generated the SVGs via a similar program
to the bitmap icons, we should regard the script as a discardable
booster stage and redesignate the SVGs themselves as the source format
for future modifications, so that they can be edited in Inkscape or
similar rather than by tinkering with Python. On the other hand,
perhaps keeping the script will make it easier to keep the icon family
consistent, e.g. if changing the style of one of the shared visual
components.)
My plan is that we should stick with the output of the previous
bitmap-generating script for all the _small_ icons, up to and
including 48 pixels, because it does a better job at low resolution.
(That was really what it was for in the first place: you can think of
it as an analogue of a scalable-font hinting system, to tune the
scaling for very low res so that all the important features are still
visible.)
I think probably I want to switch the 128-pixel icons used in the Mac
icon file over to being rendered from the SVG (though in this commit I
haven't gone that far, not least because I'll also need to prepare a
corresponding black and white version). I haven't done extensive
research yet to decide where I think the crossover point in between
is.
