[GRASS-dev] documenting the display lib in grass7

[Hamish]

Hi,

I am trying to write some new module-level display code for grass 7 but
am finding it a bit hard going due to lack of library documentation and
reference modules. Basically, I don't know what's going on and am looking
for some breadcrumbs to follow...

most D_*() functions are missing Doxygen comments saying what they do
(e.g. D_get_src() and D_get_dst()), and lib/display/displaylib.dox has
not been updated to give an overview of the new architecture.

d.graph seems to ignore the -m flag, and d.barscale and d.legend still
include (int) casts when converting % of frame to eastings,northings
which I expect are no longer needed. I don't know what d.modules to trust
and don't want to copy/perpetuate old broken code & methods.


my immediate questions are:
 - how to make the code frame compatible? is that desired? (yes please)
 - how to convert x%,y% of frame to eastings and northings and back;
    are D_a_to_b() cnversion functions still for general use?
 - is 0%,0% considered lower left or upper left of frame? (standardized)
 - is the native display units pixels, percent, or map-coords?

(I'd prefer answers directly to trunk/lib/display/, I'm happy to figure
it out from there)

I appreciate the design may still be in flux, but without any
documentation it is hard to help out / raise the bus-factor..


thanks,
Hamish