--- /dev/null
+%% Copyright (c) 2011, INRA
+%% 2004-2011, 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{e} = } crackPattern2 (@var{box}, @var{points}, @var{alpha})
+%% Create a (bounded) crack pattern tessellation
+%%
+%% E = crackPattern2(BOX, POINTS, ALPHA)
+%% create a crack propagation pattern wit following parameters :
+%% - pattern is bounded by area BOX which is a polygon.
+%% - each crack originates from points given in POINTS
+%% - directions of each crack is given by a [NxM] array ALPHA, where M is
+%% the number of rays emanating from each seed/
+%% - a crack stop when it reaches another already created crack.
+%% - all cracks stop when they reach the border of the frame, given by box
+%% (a serie of 4 points).
+%% The result is a collection of edges, in the form [x1 y1 x2 y2].
+%%
+%% E = crackPattern2(BOX, POINTS, ALPHA, SPEED)
+%% Also specify speed of propagation of each crack.
+%%
+%%
+%% See the result with :
+%% figure;
+%% drawEdge(E);
+%%
+%% @seealso{drawEdge}
+%% @end deftypefn
+
+function edges = crackPattern2(box, points, alpha, varargin)
+
+ if ~isempty(varargin)
+ speed = varargin{1};
+ else
+ speed = ones(size(points, 1), 1);
+ end
+
+ % Compute line equations for each initial crack.
+ % The 'Inf' at the end correspond to the position of the limit.
+ % If an intersection point is found with another line, but whose position
+ % is after this value, this means that another crack stopped it before it
+ % reach the intersection point.
+ NP = size(points, 1);
+ lines = zeros(0, 5);
+ for i=1:size(alpha, 2)
+ lines = [lines; points speed.*cos(alpha(:,i)) speed.*sin(alpha(:,i)) Inf*ones(NP, 1)];
+ end
+ NL = size(lines, 1);
+
+ % initialize lines for borders, but assign a very high speed, to be sure
+ % borders will stop all cracks.
+ dx = (box([2 3 4 1],1)-box([1 2 3 4],1))*max(speed)*5;
+ dy = (box([2 3 4 1],2)-box([1 2 3 4],2))*max(speed)*5;
+
+ % add borders to the lines set
+ lines = [lines ; createLine(box, dx, dy) Inf*ones(4,1)];
+
+ edges = zeros(0, 4);
+
+
+ while true
+ modif = 0;
+
+ % try to update each line
+ for i=1:NL
+
+ % initialize first point of edge
+ edges(i, 1:2) = lines(i, 1:2);
+
+ % compute intersections with all other lines
+ pi = intersectLines(lines(i,:), lines);
+
+ % compute position of all intersection points on the current line
+ pos = linePosition(pi, lines(i,:));
+
+
+ % consider points to the right (positive position), and sort them
+ indr = find(pos>1e-12 & pos~=Inf);
+ [posr, indr2] = sort(pos(indr));
+
+
+ % look for the closest intersection to the right
+ for i2=1:length(indr2)
+
+ % index of intersected line
+ il = indr(indr2(i2));
+
+ % position of point relative to intersected line
+ pos2 = linePosition(pi(il, :), lines(il, :));
+
+ % depending on the sign of position, tests if the line2 can
+ % stop the current line, or if it was stopped before
+ if pos2>0
+ if pos2<abs(posr(i2)) && pos2<lines(il, 5)
+ if lines(i, 5) ~= posr(i2)
+ edges(i, 3:4) = pi(il,:);
+ lines(i, 5) = posr(i2);
+ modif = 1;
+ end
+ break;
+ end
+ end
+ end % end processing of right points of the line
+
+
+ end % end processing of all lines
+
+ % break the infinite loop if no more modification was made
+ if ~modif
+ break;
+ end
+ end
+
+ % add edges of the surronding box.
+ edges = [edges ; box(1,:) box(2,:) ; box(2,:) box(3,:); ...
+ box(3,:) box(4,:) ; box(4,:) box(1,:) ];
+
+endfunction
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff