[Therion] Point altitude/deph, Help !

[Tarquin Wilton-Jones]

On 28/06/2022 10:04, Philippe Vernant wrote:
> Hi guys,
> 
> I’m digging this topic since I’m running in a similar issue. Would that
> be possible to have for the points with the option “altitude" something
> like :
> 640 [-30], where 640 would be the altitude and -30 the depth ?

You could use two different types of label, positioned at the same
place, with one -align left and one -align right.

These are the existing labels:

altitude, date, height, label, passage-height, remark, stationname

altitude:

General altitude label. All altitudes are exported as a difference
against grid Z origin (which is 0 by default). To display altitude on
the passage wall, use altitude option for any line point of the passage
wall.

So you set the grid origin to whatever height you want as the reference,
and you get the depth shown by the labels.

height:

Height of formations inside of the passage (like pit etc.)

label:

generic label

passage-height:

Height of the passage (floor to ceiling)

remark:

general comment

Of those, you could maybe consider abusing height for your purpose. Put
the altitude  as the height above sea level, and the "height" as the
depth below the entrance.

Alternatively, you could consider creating a custom p_u_depth that does
whatever kind of label you wanted. I have demo code for how to create
labels in your own metapost:
https://therion.speleo.sk/wiki/metapost#adding_custom_styled_labels_at_any_point_linepoint