Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / geometry-1.5.0 / geom2d / hexagonalGrid.m

diff --git a/octave_packages/geometry-1.5.0/geom2d/hexagonalGrid.m b/octave_packages/geometry-1.5.0/geom2d/hexagonalGrid.m
new file mode 100644 (file)
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+++ b/octave_packages/geometry-1.5.0/geom2d/hexagonalGrid.m
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+%% Copyright (c) 2011, INRA
+%% 2007-2011, David Legland <david.legland@grignon.inra.fr>
+%% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
+%%
+%% All rights reserved.
+%% (simplified BSD License)
+%%
+%% Redistribution and use in source and binary forms, with or without
+%% modification, are permitted provided that the following conditions are met:
+%%
+%% 1. Redistributions of source code must retain the above copyright notice, this
+%%    list of conditions and the following disclaimer.
+%%     
+%% 2. Redistributions in binary form must reproduce the above copyright notice, 
+%%    this list of conditions and the following disclaimer in the documentation
+%%    and/or other materials provided with the distribution.
+%%
+%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+%% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+%% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+%% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+%% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+%% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+%% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+%% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+%% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+%% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+%% POSSIBILITY OF SUCH DAMAGE.
+%%
+%% The views and conclusions contained in the software and documentation are
+%% those of the authors and should not be interpreted as representing official
+%% policies, either expressed or implied, of copyright holder.
+
+%% -*- texinfo -*-
+%% @deftypefn {Function File} {@var{pts} = } hexagonalGrid (@var{bounds}, @var{origin}, @var{size})
+%% Generate hexagonal grid of points in the plane.
+%%
+%%   usage
+%%   PTS = hexagonalGrid(BOUNDS, ORIGIN, SIZE)
+%%   generate points, lying in the window defined by BOUNDS (=[xmin ymin
+%%   xmax ymax]), starting from origin with a constant step equal to size.
+%%   SIZE is constant and is equals to the length of the sides of each
+%%   hexagon. 
+%%
+%%   TODO: add possibility to use rotated grid
+%% @end deftypefn
+
+function varargout = hexagonalGrid(bounds, origin, size, varargin)
+
+  size = size(1);
+  dx = 3*size;
+  dy = size*sqrt(3);
+
+
+
+  % consider two square grids with different centers
+  pts1 = squareGrid(bounds, origin + [0 0],        [dx dy], varargin{:});
+  pts2 = squareGrid(bounds, origin + [dx/3 0],     [dx dy], varargin{:});
+  pts3 = squareGrid(bounds, origin + [dx/2 dy/2],  [dx dy], varargin{:});
+  pts4 = squareGrid(bounds, origin + [-dx/6 dy/2], [dx dy], varargin{:});
+
+  % gather points
+  pts = [pts1;pts2;pts3;pts4];
+
+
+
+
+  % eventually compute also edges, clipped by bounds
+  % TODO : manage generation of edges 
+  if nargout>1
+      edges = zeros([0 4]);
+      x0 = origin(1);
+      y0 = origin(2);
+
+      % find all x coordinate
+      x1 = bounds(1) + mod(x0-bounds(1), dx);
+      x2 = bounds(3) - mod(bounds(3)-x0, dx);
+      lx = (x1:dx:x2)';
+
+      % horizontal edges : first find y's
+      y1 = bounds(2) + mod(y0-bounds(2), dy);
+      y2 = bounds(4) - mod(bounds(4)-y0, dy);
+      ly = (y1:dy:y2)';
+      
+      % number of points in each coord, and total number of points
+      ny = length(ly);
+      nx = length(lx);
+   
+      if bounds(1)-x1+dx<size
+          disp('intersect bounding box');
+      end
+      
+      if bounds(3)-x2<size
+          disp('intersect 2');
+          edges = [edges;repmat(x2, [ny 1]) ly repmat(bounds(3), [ny 1]) ly];
+          x2 = x2-dx;
+          lx = (x1:dx:x2)';
+          nx = length(lx);
+      end
+    
+      for i=1:length(ly)
+          ind = (1:nx)';
+          tmpEdges(ind, 1) = lx;
+          tmpEdges(ind, 2) = ly(i);
+          tmpEdges(ind, 3) = lx+size;
+          tmpEdges(ind, 4) = ly(i);
+          edges = [edges; tmpEdges];
+      end
+      
+  end
+
+  % process output arguments
+  if nargout>0
+      varargout{1} = pts;
+      
+      if nargout>1
+          varargout{2} = edges;
+      end
+  end
+
+endfunction
+