Bill J Gray wrote:

>
> Hi Lawrence,
>
> The following may sound vaguely familiar... I think we corresponded
> about it a year or so ago:
>
> By default, Guide switches between rendering planets as disks and
> rendering them as symbols when they reach a certain on-screen size.
> You can alter this by hitting Alt-J and entering, say,
>
> MIN_PLANET_SIZE=10
>
> The default value for this parameter is 2, meaning that if the moon
> is smaller than two units on-screen, Guide will show it as a symbol
> instead of as a shaded disk. For the goal you describe of having the
> moon (and other planets) shown as symbols more frequently, bumping
> that value up is the thing to do. I'd try setting it to 10, then
> playing with it until you get the display you want.
>
> In general, I think well of the default value... except at times
> around new moon, in "normal color" mode. In that situation, most
> of the moon is black, the background is black, and the moon doesn't
> show up very well. Your mileage may vary.

Perhaps, in some future version of Guide, this could be handled a little
differently: instead of showing the planet as a shaded disk whenever the
size of the disk is larger than MIN_PLANET_SIZE, why not require that
the
ILLUMINATED PART OF THE DISK should have this minimum size in its
"narrowest"
direction? The thickness of the crescent at its thickest part would
probably do fine and is also easy to compute as the product of the disk
diameter and the phase. With such a logic, a sufficiently thin lunar
crescent
would automatically be displayed as a symbol instead. However, during a
solar eclipse one would certainly prefer to have the lunar disk
displayed
instead of a lunar symbol, so an exception would have to be made there.
And transits of Mercury and Venus would have to be treated similarily.

> Alternatively, you can edit 'guide.dat' and add the above line (the
> actions are equivalent.)
>
> -- Bill
>
>
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