The scenario:
I have a large cave, and so to gain better control of extent of pages for
export than is possible using atlas, I define and export sub-maps. Each
submap (of maps) is a logical grouping of passages in part of the cave, each
submap either linearly placed one after the other, or above and below other
groupings of passages.
ie map AllofCave
map Submap1
map submap2
map submap3 etc
endmap AllofCave
Each of these submaps contains small local maps that are offset and
previewed above and or below. ie a short bit of passage here and there.
To facilitate flexibility of map production, the thconfig selections are
grouped and mostly commented like this.
# select AllofCave
select Submap1
select Submap2
# select Submap3 etc
In order that each of these submaps can be presented as a stand-alone output
showing its relationship with the neighbouring submaps, or even all of the
cave, each submap contains previews of its neighbouring submaps.
ie
map Submap1
preview above Submap2
preview above Submap3
<other 'map of maps' specified to define this part of cave>
<including small local map [offset] above or below>
endmap Submap1
map Submap2
preview above (or below) Submap1
preview above Submap3
<other 'map of maps' specified to define this part of cave>
<including small local map [offset] above or below>
endmap Submap2
Usually in the thconfig, one of the selects is uncommented at a time, but in
parts of the cave and for some end uses, two or three submap selects are
uncommented, as with Submap1 and Submap2 above. This is when the problem
arises.
The problem:
Having two or more selects for the same projection breaks the previews of
the small offset sections of passage in the second and subsequently selected
submaps.
ie
Submap1 and Submap3 previews are correct, but all of Submap2 offset previews
forced to above by the preview spec in Submap1
The order of selecting Submap1 and Submap2 has been swapped, so you can see
previews in the top part of the image are now correct, but the previews in
the bottom part of the image are incorrect.
Possible Workaround:
Use only ONE select (for each projection) by collecting all of the maps you
want to 'select' into a new map. The disadvantage of this is that one must
pre-empt all combinations of submaps into yet more maps. But anyway, lets
try it.
Now the individual passage offset previews are correctly rendered in all of
the submaps (Submap1 and Submap2), except that the other submap previews
(Submap3 etc) are not rendered at all. So that did not work.
Trying adding -map-level 1 to the select for the new map gives some insight,
but not a solution.
.because now the behaviour is the same as if I had uncommented multiple
selects in the thconfig file and not defined a new map at all.
The workaround/solution I came up with:
The submap previews in the submaps specified after the first one will be
ignored (somehow they are in a different map-level, but the first one is
not), so any submap previews that are wanted must be specified directly in
the new map.
ie
map newMap
preview above Submap3
Submap1
Submap2
endmap newMap
Now all of the offset previews and submap previews are displayed as they
'should' be displayed.
Question:
The Therion Book on page 50 seems to hint at the workaround/solution I
eventually came up with.
Why can the above output not be achieved by specifying multiple selects in
the thconfig? Or can it be achieved? It would be a simpler solution than
having to define a map for each of the many combinations of submaps that
users might want to produce.
I realise I don't understand 'map-level' very well. Does anyone have any
insights beyond what is written in the Therion Book and in the wiki?
Bruce
