% Create exch2 communication map and schedule for a cube sphere grid with 
% constant tile size tnx x tny.

% Use red-green-blue shorthand for cube index space specification
% In this notation cube faces are laid out as shown below
%
%             
%                         f5(nr,ng)  f6(nb,ng)
%              f3(ng,nb)  f4(nr,nb)
%   f1(nb,nr)  f2(nb,nr)
% 
nr=64;  nb=32; ng=128;
%nr=576;  nb=576; ng=576;
%nr=672;  nb=672; ng=672;
nr=32; nb=32; ng=32;
%nr=510; nb=510; ng=510;
%nr=30; nb=30; ng=30;

% Choose tile subgrid sizes for each face.
% nr,nb,ng must be integer multiples of tnx and tny.
tnx=85;tny=85;
%tnx=10;tny=10;
%tnx=16;tny=16;
tnx=16;tny=32;
%tnx=192;tny=64;

% Make list of domains. Assume MITgcm standard cube layout, three color path labeling and 
% global indexing convention.
clear domain ndomains domain_nx domain_ny
[ndomains,domain,domain_nx,domain_ny] = exch2_setup_cs6_domains(nr,nb,ng);

% Now create basic tile definitions for each domain with their offsets within the domain
% tn[xy]        :: tile extents in x and y
% tbase[xy]     :: offset of tile local coords from domain coords
%               :: tdom[xy] = tlocal[xy] + tbase[xy]
% t[xy]globallo :: global composite domain coordinate associated with
%               :: tlocal[xy]=(1,1)
% mydomain      :: domain number the tile belongs to
% tileid        :: identifier number for tile
% tx            :: tile x coordinate within domain tiling
% ty            :: tile y coordinate within domain tiling
clear tile
[tile,ntiles,ierr,domain]= ...
 exch2_setup_cs6_tiles(tnx,tny,domain,ndomains);

% Set neighbor domains for each tile
[tile] = exch2_setup_cs6_get_neighbor_domains(tile, domain, ntiles);

% Let try and figure out what points I send my edges to. We do this by a search procedure 
% rather than a functional relationship. The search procedure visits each edge of each tile 
% in turn.  For internal edges (edges that don't cross a domain boundary) the index range at 
% +/-1 in the normal direction to the edge is searched for. This identifies all the tiles that % border this tile.
[tile] = exch2_setup_cs6_get_internal_neighbor_tiles(       tile, domain, ntiles);
[tile] = exch2_setup_cs6_get_internal_neighbor_index_ranges(tile, domain, ntiles);

[tile] = exch2_setup_cs6_get_external_neighbor_tiles(       tile, domain, ntiles);
% Draw a picture of the domain and its tiles in the standard cube layout
exch2_setup_cs6_plot(domain, tile, tnx, tny);

% Write attributes for a tile
exch2_setup_cs6_print( domain, tile, 1)