Small gas pressure rendering improvements are needed for Mobile version 2

Linus Torvalds torvalds at
Fri Oct 6 09:58:57 PDT 2017

On Fri, Oct 6, 2017 at 12:15 AM, Willem Ferguson
<willemferguson at> wrote:
> 1) Look at Dive2_desktop. The gas composition as well as start and end
> pressures of cylinders are indicated in an orderly way.

Well, to be honest, even on the desktop, those gas names and pressures
are not really "orderly", it's just

 (a) we've done a few random tweaks to make them mostly look ok

 (b) the desktop profile simply has relatively more room to play with
(even if the mobile side has as many pixels, people want bigger fonts
etc on mobile, so mobile is more crowded).

So the desktop profile is fundamentally "more forgiving" to begin with
wrt layout, and the mobile side has gptten way less layout attention
anyway. The actual code to lay things out should be mostly shared,
despite things looking somewhat different.

> The positioning of the pressure data for the mobile representation is seriously problematic.

That's actually very odd. The positioning should be exactly the same
code, just using different fonts.

But looking at your images, the desktop does put the pressure above,
and the gas name below, and the mobile does the opposite.

I have no idea why that difference should happen, nothing in the code
looks like it should make such a change. But I don't know the mobile
code at all, so I'm just assuming that it uses the same widget.

For all I know it could be due to random coordinate system
differences, which just makes our offsets come out wrong. Our
"value/label_y_offset" code is certifiably insane, starting with using
various random numbers (-0.5, 5 and -7), but then mixing it with
totally insane values ("axisLog = log10(log10(axisRange));" is the
truly ramblings of a modern-day Nostradamus - completely and utterly
insane, but so interesting that I never dared do anything but just
quote it with reverence).

I think you should just think of it as "performance art". It's not
pretty in a "classical" meaning, but look at Picasso - he is revered
for his odd view of the universe and his fractured paintings.

Subsurface mobile is the "Picasso of dive log software" when it comes
to multiple gas pressures. You may just have a Guernica on your

Or something.

> 3) Now, the issue of dive plans stored with the real dive. Look at
> Dive1_desktop. Data are reasonable well presented, the dive plan being
> accessible as dive computer 2; the resultant real dive log being dive
> computer 1. Consider Dive1_mobile, where the cylinder pressures for the dive
> plan is erroneously plotted over those of the real dive log.

Ok, this is a separate issue, I'm not sure what to do about multiple
dive computers at all on the mobile side.


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