squareNeighbors returns neighbors of arbitrary order

geometry/geometry_tools/squareNeighbors.m

@@ -1,14 +1,21 @@
-function ind = squareNeighbors(RowsCols,Nid)
+function ind = squareNeighbors(RowsCols,Nid,varargin)
 % return the neighbor ids in a square grid
 %
 %
 
 [col,row] = meshgrid(1:RowsCols(2),1:RowsCols(1));
 
-dRow = [0 1 0 -1];
-dCol = [1 0 -1 0];
+order = get_option(varargin,'order',0);
+if order == 0
+  dRow = [0 1 0 -1];
+  dCol = [1 0 -1 0];
+else
+  [dRow,dCol] = meshgrid(-order:order);
+  dRow(2*order^2+2*order+1) = [];
+  dCol(2*order^2+2*order+1) = [];
+end
 
-if nargin == 2
+if nargin >= 2 && ~isempty(Nid)
   ind = calcInd(Nid);
 else
 
@@ -18,17 +25,29 @@
   end
 
 end
- 
+
   function indLocal = calcInd(Nid)
 
   nrow = row + dRow(Nid);
   ncol = col + dCol(Nid);
 
   % ensure coordinates are within the range
-  ncol = max(min(ncol,RowsCols(2)),1);
-  nrow = max(min(nrow,RowsCols(1)),1);
+  if check_option(varargin,'strict')
+
+    indLocal = zeros(size(nrow));
+    isInside = ~(ncol<1 | ncol>RowsCols(2) | nrow<1 | nrow>RowsCols(1));
+
+    indLocal(isInside) = sub2ind(RowsCols,nrow(isInside),ncol(isInside));
 
-  indLocal = sub2ind(RowsCols,nrow,ncol);
+  else
+    ncol = max(min(ncol,RowsCols(2)),1);
+    nrow = max(min(nrow,RowsCols(1)),1);
+
+    indLocal = sub2ind(RowsCols,nrow,ncol);
+  end
+
+
+
 
   end