function editmask(grid_file,coast_file);

% EDITMASK interactive Land/Sea mask editing for CROCO
%    EDITMASK(GRID_FILE,COAST_FILE) is tool for manual editing of the
%    Land/Sea mask on RHO-points.  To accelerate the proccessing, the
%    Land/Sea mask is edited in (I,J) grid coordinates.  GRID_FILE is
%    the GRID NetCDF file containing the grid and mask. COAST_FILE is
%    a MAT file holding the coastline (lon,lat) coordinates  or (I,J)
%    grid coordinates.  If the (I,J) coordinates are not provided, it
%    will compute and write them into file. If called without, one or
%    both arguments, it will prompt for the needed file name(s).
%
%    Mouse shortcuts:
%
%    double click ==> Zoom in
%    right  click ==> Zoom out
%    middle click ==> change editing mode
%
%    Calls: READ_MASK, WRITE_MASK and UVP_MASKS functions.
%           BUTTON, RADIOBOX, TEXTBOX, AXISSCROLL,
%
% ashcherbina@ucsd.edu, 11/15/01


% Define and initialize persistent variables.

persistent changed rmask rlon rlat bath mask hplot hcst ha Lp Mp mx my
persistent mfile fig zooming xx yy xl yl xcst ycst

% Single global variable to pass info to/from the callback routines.

global GUI

% Set colormap: first two entries - land, second pair - sea

%CMAP=[0 1 0;.5 1 0;0 .7 1;.3 0 1];
CMAP=[.5 1 0;1 1 0;0 0 .7;0 0 1];

% Set coastline line color and width.

LineColor='k';
LineWidth=1;

% Check input arguments.

if (nargin < 1 | isempty(grid_file)),
  grid_file='*.nc';
end,
if (nargin < 2 | isempty(coast_file)),
  coast_file='*.mat';
end,

FIGURE_NAME='Land/Sea Mask Editor';

%=======================================================================
% The EDITMASK function is also used as a CallBack for some of the
% uicontrols,  so we need to figure out, what's required by looking
% at the 'grid_file' parameter.
%=======================================================================

switch lower(grid_file),

%-----------------------------------------------------------------------
% Zoom-in.
%-----------------------------------------------------------------------

  case 'oct_zoomin',

    disable_click;
    editmask move;
    zooming=1;
    waitforbuttonpress
    xx0=xx; yy0=yy;                             % save current pointer position
    rbbox;                                      % track rubberband rectangle
    xx1=xx; yy1=yy;                             % new pointer position
    if ((xx0 ~= xx1) & (yy0 ~= yy1)),           % trim limits and set zoom
      xx0(xx0<0)=0;  xx0(xx0>xl(2))=xl(2);
      xx1(xx1<0)=0;  xx1(xx1>xl(2))=xl(2);
      yy0(yy0<0)=0;  yy0(yy0>yl(2))=yl(2);
      yy1(yy1<0)=0;  yy1(yy1>yl(2))=yl(2);
      xlim([min([xx0 xx1]), max([xx0 xx1])]);
      ylim([min([yy0 yy1]), max([yy0 yy1])]);
      axisscroll;
    end,
    enable_click;
    zooming=0;

%-----------------------------------------------------------------------
% Zoom-out.
%-----------------------------------------------------------------------

  case 'oct_zoomout',

    xlim(xl);
    ylim(yl);
    axisscroll;

%-----------------------------------------------------------------------
% Edit Land/Sea mask.
%-----------------------------------------------------------------------

  case 'click',

    button=get(gcf, 'SelectionType');
    if (strcmp(button,'alt')),                  % zoom out on right click
      editmask oct_zoomout;
      return;
    end,
    if (strcmp(button,'open')),                 % zoom in on double click
      editmask oct_zoomin;
      return;
    end,
    if (strcmp(button,'extend')),               % cycle modes on middle click
      m=mod(GUI.mode,3)+1;
      eval(get(GUI.mode_h(m),'callback'));
      editmask oct_zoomout;
      return;
    end,
    if (within(xx,xlim) & within(yy,ylim)),     % left click within edit area
      disable_click;
      switch GUI.tool
        case 1,                                 % point edit
          ix=floor(xx+1.5);
          iy=floor(yy+1.5);
          switch GUI.mode
            case 1,                             % toggle between land and sea
              rmask(ix,iy)=~rmask(ix,iy);
            case 2,                             % set land
              rmask(ix,iy)=0;
            case 3,                             % set sea
              rmask(ix,iy)=1;
	  end,
        case 2,                                 % area edit
          xx0=xx; yy0=yy;                       % save current pointer position
          rbbox;                                % track rubberband rectangle
          xx1=xx; yy1=yy;                       % new pointer position
          idsel=find((mx-xx0-1).*(mx-xx1-1)<=0 & ...
                     (my-yy0-1).*(my-yy1-1)<=0);% indicies within rectangle
          switch GUI.mode
            case 1,
              rmask(idsel)=~rmask(idsel);       % toggle between land and sea
            case 2,
              rmask(idsel)=0;                   % set land
            case 3,
              rmask(idsel)=1;                   % set sea
          end,
      end,
      changed=1;
      enable_click;
      editmask refresh;
    end,

%-----------------------------------------------------------------------
% Update mask by changin colormap.
%-----------------------------------------------------------------------

  case 'refresh',

    cdata=rmask*2+mod(mod(mx,2)+mod(my,2),2)+1;
    set(hplot,'cdata',cdata');
    nm=[FIGURE_NAME,' - ', mfile];
    if (changed),
      nm=[nm,'*'];
    end,
    set(fig,'name',nm);

%-----------------------------------------------------------------------
% Pointer movement: update pointer coordinates on menu.
%-----------------------------------------------------------------------

  case 'move',

    xy=get(gca,'currentpoint');
    xx=xy(1,1); yy=xy(1,2);
    if (within(xx,xlim) & within(yy,ylim)),
      s=sprintf('[%d,%d]',floor(xx+.5),floor(yy+.5));
      if (zooming),
        pointer('zoom');
      elseif (GUI.tool==1),
        pointer('point');
      elseif GUI.tool==2,
        pointer('rect');
      end,
    else,
      s='---';
      pointer('arrow');
    end,
    set(GUI.pos_h,'string',s);

%-----------------------------------------------------------------------
% Compute U-, V- and PSI masks.  Write out into GRID NetCDF file.
%-----------------------------------------------------------------------

  case 'save',

    [umask,vmask,pmask]=uvp_masks(rmask);
    mask=rmask;
    write_mask(mfile,rmask,umask,vmask,pmask);
    changed=0;
    editmask refresh;

%-----------------------------------------------------------------------
% Undo changes: restore last saved mask.
%-----------------------------------------------------------------------

  case 'undo',

    rmask=mask;
    changed=0;
    editmask refresh;

%-----------------------------------------------------------------------
%  Done: inquire to save mask changes.
%-----------------------------------------------------------------------

  case 'exit',

    if (~changed),
      oct_delete(gcf);
    else
      res=questdlg('The mask has been changed. Save?',FIGURE_NAME);
      switch res
        case 'Yes',
          editmask save;
          disp('Mask has been saved');
          oct_delete(gcf);
        case 'No',
          disp('Mask has NOT been saved');
          oct_delete(gcf);
      end,
    end,

%-----------------------------------------------------------------------
% Help.
%-----------------------------------------------------------------------

  case 'help',

    show_help;

%-----------------------------------------------------------------------
% Initialize: read mask and coastline data.
%-----------------------------------------------------------------------

  otherwise,

% Kill all windows.

    oct_delete(findobj(0,'tag','maskeditor'));

% If appropriate, inquire input file names.

    if (any(grid_file=='*')),
      [fn,pth]=uigetfile(grid_file,'Select CROCO grid file...');
      if (~fn),
        return,
      end;
      grid_file=[pth,fn];
      oct_make_coast(grid_file)
    end,
    if (any(coast_file=='*')),
      [fn,pth]=uigetfile(coast_file,'Select Coastline file...');
      if (~fn),
        return,
      end;
      coast_file=[pth,fn];
    end,

% Read in grid data.

   mfile=grid_file;
   [spherical,rlon,rlat,bath,mask]=read_mask(grid_file);
   rmask=mask;
   [Lp,Mp]=size(mask);
   [mx,my]=ndgrid(1:Lp,1:Mp);

% Read in coastline data. If appropriate, compute coastline (I,J)
% grid indices.

   load(coast_file);

   if (exist('C')),
     xcst=C.Icst;
     ycst=C.Jcst;
     clear C;
   elseif (exist('lon') & exist('lat')),
     [C]=ijcoast(grid_file,coast_file);
     xcst=C.Icst;
     ycst=C.Jcst;
     clear C lat lon;
   else,
     error('Coast file should contain "lon" and "lat" vectors');
   end,

% Initialize the window.

   fig=figure('NumberTitle','off',...
              'tag','maskeditor',...
              'DoubleBuffer','on',...
              'backingstore','off',...
              'menubar','none');
   cdata=rmask*2+mod(mod(mx,2)+mod(my,2),2)+1;
   gx=mx(:,1)-1;
   gy=my(1,:)-1;
   axes('position',[0.0554 0.1024 0.7518 0.8405]);
   hplot=image(gx,gy,cdata','cdatamapping','direct','erasemode','normal');
   set(gca,'YDir','normal',...
           'drawmode','fast',...
           'layer','top',...
           'tickdir','out');
   colormap(CMAP);
   hold on;
   hline=plot(xcst,ycst,LineColor);
   set(hline,'LineWidth',LineWidth);
   xl=xlim; yl=ylim;
   changed=0;
   setgui;
   editmask refresh;

end,

return


function setgui

%-----------------------------------------------------------------------
% set-up Land/Sea mask editing menu bottons.
%-----------------------------------------------------------------------

textbox([.85 .85 .145 .14], ....
        '(i,j)',{'0,0'},'pos');

radiobox([.85 .65 .145 .19], ...
         'Edit Mode',{'Toggle Land/Sea','Set Land','Set Sea'},'mode');

radiobox([.85 .5 .145 .14], ...
         'Edit Tool',{'Point edit','Area edit'},'tool');

button([.85 .4 .145 .05], ...
       'Zoom In',[mfilename ' oct_zoomin']);

button([.85 .35 .145 .05], ...
       'Zoom Out',[mfilename ' oct_zoomout']);

button([.85 .25 .145 .05], ...
       'Undo',[mfilename ' undo']);

button([.85 .2 .145 .05], ...
       'Save',[mfilename ' save']);

button([.85 .1 .145 .05], ...
       'Exit',[mfilename ' exit']);

axisscroll('r')
axisscroll('t')
set(gcf,'WindowButtonMotionFcn',[mfilename ' move;'],...
        'CloseRequestFcn',[mfilename ' exit;'],...
        'interruptible','on');
enable_click;

return

function disable_click

%-----------------------------------------------------------------------
% Disable pointer clicking on current figure.
%-----------------------------------------------------------------------

set(gcf,'WindowButtonDownFcn','');

return

function enable_click

%-----------------------------------------------------------------------
% Enable pointer clicking on current figure.
%-----------------------------------------------------------------------

set(gcf,'WindowButtonDownFcn',[mfilename ' click;']);

return

function r=within(a,b)


%-----------------------------------------------------------------------
% Check if 'a' is within the range of 'b'.
%-----------------------------------------------------------------------

r=(a>=b(1) & a<= b(2));

return