Proposal for a new source code structure

Please modify and improve:
  - add missing modules
  - re-organize

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$Id$


General ideas

New concepts:
 - the I/O routines (GRASS data import/export library routines) should be
   removed from src/libes/gis and replaced by Frank Warmerdams libgrass[io]
   These "extracted" routines should be treated as plugin and released 
   under LGPL to allow optional commerical use in commercial packages
   which want to read/write into GRASS database directly
 - The raster data storage structure should be changed to the G3D
   structure: all files related to a raster map should go into one
   directory. Currently many files are spreaded in many directories.
   An example for the G3D data structure can be found here:
   http://grass.itc.it/grid3d/index.html (sample dataset)


As grass5.1 shall take off as soon as possible, we should start the
directory structure debate. My draft proposal is looking like this:


grass51/

# core includes libs, docs, import/export and basic modules:
    /core                 (the GRASS basic package)
	/include	: global include files

	/lib		  (read src/libes/README for further design comments)
	    /bitmap     : bitmap library for X Window Bitmaps
	    /btree      : binary tree library
	    /coorcnv    : coordinate conversion and datum support library
	    /datetime   : DateTime library
	    /dbmi       : database management interface database drivers
	    /display    : display lib (was: D/ )
	    /drivers
		/cell   : CELL driver (was: display/)
		/digitizer: raw library for general digitizer support
		/htmlmap: HTMLMAP driver
		/paint  : paint library (from paint/ )
		/xdriver: XDRIVER
	    /dspf       : G3D display files library
	    /formats
		/dlg    : library to manage DLG files
		/sdts   : library to manage SDTS files (was: src.contrib/..)
		/sgirgb : library to manage SGIs RGB-format (was: libimage)
	    /fonts      : hershey fonts
	    /front.end  : cmd/inter frontend
	    /g3d        : G3D raster volume library
	    /geom	: geometrical calculations... (will be detri)
	    /gis        : main GRASS library (remove import/export routines)
	    /gmath      : generic mathematical functions (to BLAS/LAPACK libs)
	    /ibtree     : integer clone of btree lib (needed?)
	    /icon       : icon library (required for PS/Paint)
	    /imagery    : imagery library including image3 extra library
	    /init       : GRASS startup (was: src/general/init/ )
	    /java       : GRASS JAVA support (was src.garden/grass.java/ )
	    /linkm      : linked list memory manager
	    /lock       : locking mechanism for GRASS monitors and files
	    /ogsf       : ported gsurf library (required for NVIZ)
                               -> perhaps store under NVIZ only?
	    /plugins      (keeps external libs)
		/bwidget : tcl/tk extra library
		/gdal    : GDAL raster lib
		/gdbm    : database support for GRASS (or Berkeley DB)
		/libgrassio: GRASS import/export lib from Frank Warmerdam
		/proj    : PROJ 4.x library from Frank Warmerdam et al.
		/shapelib: SHAPE support lib from Frank Warmerdam
	    /raster     : GRASS raster library
	    /rowio      : row in/out library  
	    /rst_gmsl   : library for interpolation with reg. splines w.t.
	    /segment    : segment library
	    /sites      : GRASS sites library (extract from gis/ )
	    /testsuite  : testsuite
	    /vask       : Curses management library
	    /vector     : GRASS vector library
		/Vlib     : portable GRASS vector functions
		/dig_atts : library to read and write from attribute files
		/diglib   : more GRASS vector functions
		/georef   : Imagery Georeferencing Programs
		/transform: transformations from one coord. system to another (was libes/)

	/docs
	    /docs
	    /html
		/html_docs_go_here

	/exchange    (import/export modules)
	    /misc
		/m.e00
	    /raster
		/r.arc  (contains r.in.arc/r.out.arc)
		/r.ascii
		/r.tif
		...
	    /scripts    (move import/export scripts here from global scripts)
	    /sites
		/s.ascii
	    /vector
		/v.ascii
		/v.shape
		...

#now a set of basic modules follows:
	/display
	   /basic_modules_go_here

	/general
	   /basic_modules_go_here

	/gui
	    /python
	    /tcltkgrass

	/misc
	   /basic_modules_go_here

	/paint
	    /paint_modules_go_here

	/postscript
	    /ps_modules_go_here

	/raster
	    /basic_modules_go_here

	/sites
	    /basic_modules_go_here

	/vector
	    /basic_modules_go_here


#now topic-oriented packages follow:

# vis-package:
    /visualization
	/nviz
	/sg3d
	/xganim

    
#hydro-dem-erosion-package:
    /hydrology_dem
	/raster
	    /raster_hydro_dem_modules


#image-processing-package:
    /imageprocessing
	/imagery
	    /image_proc_modules


#database-package:
    /database
	/generic (db.* driver improved by Radim)
	/oracle
	/postgresql
	    

#G3D-package:
    /g3d  (was: src.contrib/GMSL/g3d)
	/general3
	/raster3
	/scripts3
	/sites3
	    

#extended-raster-package:
    /raster_extended
	/fuzzy_logic
	/...


#interpolation-package:
    /raster
	/r.bilinear
	/...
    /sites
    /vector (was: mapdev)

#simulation-models-package:
    /raster
	/casc2d
	/topmodel
	/erosion


#more?

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Note: Useful modules from src.contrib section shall be merged into
      directory structure.

Questions:
  - core-package: shall we move the "/lib/plugins" to "/plugins" ?
  - shall we keep the unused directory?

Proposal:
 - the number of import/export modules scripts needs to be heavily reduced.
   At time there are 92 tools for import/export/tape analysis...

 - Idea: The raster database structure should be changed to the G3D
   structure: all files related to a raster map should go into one
   directory. Currently many files are spreaded in many directories.
   An example for the G3D data structure can be found here:
   http://grass.itc.it/grid3d/index.html (sample dataset)