--- /dev/null
+## Copyright (C) 2002-2009 Etienne Grossmann <etienne@egdn.net>
+##
+## This program is free software; you can redistribute it and/or modify it under
+## the terms of the GNU General Public License as published by the Free Software
+## Foundation; either version 3 of the License, or (at your option) any later
+## version.
+##
+## This program is distributed in the hope that it will be useful, but WITHOUT
+## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+## details.
+##
+## You should have received a copy of the GNU General Public License along with
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## s = vrml_surf (x, y, z [, options] ) - code for a VRML surface
+## s = vrml_surf (z [, options] )
+##
+## Returns vrml97 code for a Shape -> IndexedFaceSet node representing a
+## surface passing through the given points.
+##
+## x : RxC or C : X coordinates of the points on the surface
+## y : RxC or R : Y " "
+## z : RxC : Z " "
+##
+## s : string : The code
+##
+## If x and y are omitted, they are assumed to be linspace(-1,1,C or R).
+## Points presenting one or more 'inf' or 'nan' coordinates are ignored.
+##
+## Options :
+##
+## "col" , col : 3 : RGB Color, default = [0.3,0.4,0.9]
+## or 3x(R*C): Color of vertices (vrml colorPerVertex is TRUE).
+## or 3x((R-1)*(C-1))
+## : Color of facets
+## or 1 : Reflectivity (equivalent to [col,col,col] in RGB)
+## or R x C : Reflectivity of vertices
+## or 1x(R*C)
+## or (R-1)x(C-1)
+## or (R-1)*(C-1)
+## : Reflectivity of facets.
+##
+## RGB and reflectivity values should be in the [0,1] interval.
+##
+## "checker", c : 1x2 : Color as a checker. If c(1) is positive, checker has
+## c(1) rows. If it is negative, each checker row is c(1) facets
+## high c(2) likewise determines width of checker columns.
+## "checker", c : 1x1 : Same as [c,c].
+##
+## "zcol", zc : 3xN : Specify a colormap. The color of each vertex is
+## interpolated according to its height (z).
+##
+## "zgray" : Black-to-white colormap. Same as "zcol", [0 1;0 1;0 1].
+##
+## "zrb" : Red-to-blue. Same as "zcol", [0 7 10;0 0 2;7 19 2]/10.
+##
+## "steps" : Represent surface as a piecewise constant Z = f(X,Y) function
+##
+## "bars" : Represent surface as a bar plot
+##
+## "tran", tran : 1x1 : Transparency, default = 0
+##
+## "creaseAngle", a
+## : 1 : vrml creaseAngle The browser may smoothe the fold
+## between facets forming an angle less than a.
+## default = 0
+## "smooth" : same as "creaseAngle",pi.
+## "tex", texFile
+##
+## See also: vmesh(), vrml_faces(), test_moving_surf()
+
+function s = vrml_surf (x, y, z,varargin)
+
+if (nargin <= 1) || ischar(y), # Cruft to allow not passing x and y
+ zz = x ;
+ [R,C] = size (zz);
+ [xx,yy] = meshgrid (linspace (-1,1,C), linspace (-1,1,R));
+ ## ones(R,1)*[1:C] ;
+ ## yy = ## [1:R]'*ones(1,C) ;
+ ##if nargin >=3,
+ ## s = vrml_surf ( xx, yy, zz, y, z, varargin{:} );
+ ## return
+ ##elseif nargin >=2,
+ ## s = vrml_surf ( xx, yy, zz, y, varargin{:} );
+ ## return
+ ##end
+ if nargin >= 3
+ varargin = {y, z, varargin{:}};
+ elseif nargin >= 2
+ varargin = {y, varargin{:}};
+ end
+
+ x = xx ; y = yy ; z = zz ;
+end
+
+defaultCol = [0.3; 0.4; 0.9];
+
+ # Read options
+ # Default values
+
+upper = 1; # Do "upper" triangulation of square grid
+tran = 0 ; # Transparency
+col = defaultCol ; # Color
+checker = 0; # Checkered coloring
+colorPerVertex = 1; # Color vertices or faces
+zrb = zgray = zcol = 0; # Color by elevation
+emit = 0; # emissiveColor or diffuse only
+smooth = creaseAngle = nan ;
+steps = 0;
+bars = 0;
+tex = 0;
+bwid = -1;
+DEFcoord = DEFcol = ""; # Give a name to VRML objects
+
+if numel (varargin)
+
+ op1 = " tran col creaseAngle emit colorPerVertex checker DEFcoord DEFcol zcol bwid tex ";
+ op0 = " smooth zgray zrb steps bars " ;
+
+ default = tars (tran, col, creaseAngle, emit, colorPerVertex, steps, bars, \
+ bwid, DEFcoord, DEFcol, zcol, smooth, checker, zgray, zrb, tex);
+
+ s = read_options (varargin,"op0",op0,"op1",op1,"default",default);
+
+ tran= s.tran;
+ col= s.col;
+ creaseAngle= s.creaseAngle;
+ emit= s.emit;
+ colorPerVertex= s.colorPerVertex;
+ DEFcoord= s.DEFcoord;
+ DEFcol= s.DEFcol;
+ zcol= s.zcol;
+ smooth= s.smooth;
+ steps= s.steps;
+ bars= s.bars;
+ bwid= s.bwid;
+ tex= s.tex;
+ if bwid >= 0
+ bars = 1;
+ end
+ checker= s.checker;
+ zgray= s.zgray;
+ zrb= s.zrb;
+end
+## keyboard
+if ! isnan (smooth), creaseAngle = pi ; end
+
+[R,C] = size(z);
+if any (size (x) == 1), x = ones(R,1)*x(:)' ; end
+if any (size (y) == 1), y = y(:)*ones(1,C) ; end
+
+if bars
+
+ if bwid < 0
+ bwid = 2/3;
+ end
+ brad = bwid/2;
+
+ R4 = 4*R;
+ C4 = 4*C;
+ x2 = y2 = z2 = zeros (R4,C4);
+
+ x2(:,1) = x2(:,2) = kron ((1+brad)*x(:,1) - brad*x(:,2), [1;1;1;1]);
+ x2(:,C4-1) = x2(:,C4) = kron ((1+brad)*x(:,C) - brad*x(:,C-1), [1;1;1;1]);
+ x2(:,5:4:C4) = x2(:,6:4:C4) = kron ((1-brad)*x(:,2:C) + brad*x(:,1:C-1), [1;1;1;1]);
+ x2(:,3:4:C4-4) = x2(:,4:4:C4-4) = kron ((1-brad)*x(:,1:C-1)+brad*x(:,2:C), [1;1;1;1]);
+
+ y2(1,:) = y2(2,:) = kron ((1+brad)*y(1,:) - brad*y(2,:), [1 1 1 1]);
+ y2(R4-1,:) = y2(R4,:) = kron ((1+brad)*y(R,:) - brad*y(R-1,:), [1 1 1 1]);
+ y2(5:4:R4,:) = y2(6:4:R4,:) = kron ((1-brad)*y(2:R,:) + brad*y(1:R-1,:), [1 1 1 1]);
+ y2(3:4:R4-4,:) = y2(4:4:R4-4,:) = kron ((1-brad)*y(1:R-1,:) + brad*y(2:R,:), [1 1 1 1]);
+
+ z2([2:4:R4;3:4:R4],[2:4:C4;3:4:C4]) = kron(z,ones(2));
+
+ x = x2;
+ y = y2;
+ z = z2;
+ R = R4;
+ C = C4;
+
+ if numel (size (col)) == 2 && all (size (col) == size (defaultCol)) && all (col == defaultCol)
+ col = [col, 0.8*col, 0.9*col];
+ end
+ if numel (col) == 3
+ col = col(:);
+ topCol = col;
+ botCol = col;
+ sideCol = [col,col,col,col];
+ elseif numel (col) == 6
+ col = col(:);
+ topCol = col(1:3);
+ botCol = col(1:3);
+ sideCol = col(4:6)*ones(1,4);
+ elseif numel (col) == 9
+ col = col(:);
+ topCol = col(1:3);
+ botCol = col(7:9);
+ sideCol = col(4:6)*ones(1,4);
+ end
+ col = ones(3, R-1, C-1);
+ for i=1:3
+ col(i,2:4:R-1,2:4:C-1) = topCol(i);
+ col(i,4:4:R-1,:) = botCol(i);
+ col(i,:,4:4:C-1) = botCol(i);
+ col(i,3:4:R-1,2:4:C-1) = sideCol(i,1);
+ col(i,2:4:R-1,1:4:C-1) = sideCol(i,2);
+ col(i,1:4:R-1,2:4:C-1) = sideCol(i,3);
+ col(i,2:4:R-1,3:4:C-1) = sideCol(i,2);
+ end
+ iOnFloor = find (! z(1:R-1,1:C-1));
+ if ! isempty (iOnFloor)
+ ## keyboard
+ col(3*(iOnFloor-1)+1) = botCol(1);
+ col(3*(iOnFloor-1)+2) = botCol(2);
+ col(3*(iOnFloor-1)+3) = botCol(3);
+ end
+
+elseif steps # Constant by parts
+
+ # Intermediate coordinates (R+1) x (C+1)
+ x2 = (x([1,1:R],[1,1:C]) + x([1,1:R],[1:C,C])) / 2;
+ y2 = (y([1,1:R],[1:C,C]) + y([1:R,R],[1:C,C])) / 2;
+
+ # Extend extremities so all patches have same size
+ x2(1,:) = 2*x2(1,:) - x2(2,:);
+ x2(:,1) = 2*x2(:,1) - x2(:,2);
+ x2(R+1,:) = 2*x2(R+1,:) - x2(R,:);
+ x2(:,C+1) = 2*x2(:,C+1) - x2(:,C);
+
+ y2(1,:) = 2*y2(1,:) - y2(2,:);
+ y2(:,1) = 2*y2(:,1) - y2(:,2);
+ y2(R+1,:) = 2*y2(R+1,:) - y2(R,:);
+ y2(:,C+1) = 2*y2(:,C+1) - y2(:,C);
+
+ # Duplicate intermediate values 2R x 2C
+ ii = [1,([1;1]*(2:R))(:)',R+1];
+ jj = [1,([1;1]*(2:C))(:)',C+1];
+
+ x2 = x2(ii,jj);
+ y2 = y2(ii,jj);
+
+ z2 = z([1;1]*(1:R),[1;1]*(1:C));;
+ x = x2;
+ y = y2;
+ z = z2;
+
+ if checker
+ col = checker_color (checker, col, 2*R,2*C);
+ end
+ if numel (col) == R*C
+ col = [1;1;1]*col(:)';
+ end
+ if numel (col) == 3*R*C
+ col = reshape (col, 3,R,C);
+ col2 = zeros (3,2*R-1,2*C-1);
+ col2(1,:,:) = defaultCol(1);
+ col2(2,:,:) = defaultCol(2);
+ col2(3,:,:) = defaultCol(3);
+ col2(:,1:2:end,1:2:end) = col;
+ col = reshape (col2,3,(2*R-1)*(2*C-1));
+ end
+
+ R *= 2;
+ C *= 2;
+end
+
+pts = [x(:)';y(:)';z(:)'];
+
+keepp = all (!isnan(pts) & finite(pts)) ;
+keepip = find (keepp);
+if tex
+ [texX,texY] = meshgrid (linspace (0,1,C), linspace (0,1,R));
+ texXY = [texX(:)'; texY(:)'];
+end
+
+trgs = zeros(3,2*(R-1)*(C-1)) ;
+
+## Points are numbered as
+##
+## 1 R+1 .. (C-1)*R+1
+## 2 R+2 :
+## : : :
+## R 2*R .. C*R
+##
+
+
+## (x,y), (x,y+1), (x+1,y) i.e. n, n+1, n+R
+
+if !upper # Do regular triangulation
+ ## Triangles are numbered as :
+ ##
+ ## X = (R-1)*(C-1)
+ ## +-----+-----+-----+-----+-----+
+ ## | /| /| /| /|-R+1/|
+ ## | 1 / | R / | / | / |R*C/ |
+ ## | / | / | / | / | / |
+ ## | /X+1| /X+R| / | / | / |
+ ## |/ |/ |/ |/ |/ |
+ ## +-----+-----+-----+-----+-----+
+ ## | /| /| /| /| /|
+ ## | 2 / |R+2/ | / | / | / |
+ ## | / | / | / | / | / |
+ ## | / | / | / | / | / |
+ ## |/ |/ |/ |/ |/ |
+ ## +-----+-----+-----+-----+-----+
+ ## : : :
+ ## : : :
+ ## +-----+-----+-----+-----+-----+
+ ## | /| /| /| /| /|
+ ## |R-1/ |2*R/ | / | / |C*R/ |
+ ## | / |-1/ | / | / | / |
+ ## | /X+R| / | / | / | /C*R|
+ ## |/ |/ |/ |/ |/ X+ |
+ ## +-----+-----+-----+-----+-----+
+
+ tmp = 1:(R-1)*(C-1);
+
+ trgs(1,tmp) = ([1:R-1]'*ones(1,C-1) + R*ones(R-1,1)*[0:C-2])(:)';
+ trgs(2,tmp) = ([ 2:R ]'*ones(1,C-1) + R*ones(R-1,1)*[0:C-2])(:)';
+ trgs(3,tmp) = ([1:R-1]'*ones(1,C-1) + R*ones(R-1,1)*[1:C-1])(:)';
+
+ tmp += (R-1)*(C-1);
+
+ trgs(1,tmp) = ([1:R-1]'*ones(1,C-1) + R*ones(R-1,1)*[1:C-1])(:)';
+ trgs(2,tmp) = ([ 2:R ]'*ones(1,C-1) + R*ones(R-1,1)*[0:C-2])(:)';
+ trgs(3,tmp) = ([ 2:R ]'*ones(1,C-1) + R*ones(R-1,1)*[1:C-1])(:)';
+
+else # Do "upper" triangulation
+
+ ## Each triangle is +-----+ +-----+
+ ## the highest of either | /| or |\ |
+ ## | / | | \ |
+ ## | / | | \ |
+ ## | / | | \ |
+ ## |/ | | \|
+ ## +-----+ +-----+
+
+
+ tmp = 1:(R-1)*(C-1);
+ tmp2 = reshape(1:R*C,R,C);
+ foo1 = z(1:R-1,1:C-1) + z(2:R,2:C);
+ foo2 = z(2:R,1:C-1) + z(1:R-1,2:C);
+ tmp3 = (!isnan(foo1) & (isnan (foo2) | foo1 > foo2))(:)';
+
+ trgs(1,tmp) = tmp2(1:R-1,1:C-1)(:)';
+ trgs(2,tmp) = tmp2(2:R,1:C-1)(:)';
+ trgs(3,tmp) = trgs(1,tmp) + R + tmp3 ;
+ tmp += (R-1)*(C-1);
+ trgs(1,tmp) = tmp2(1:R-1,2:C)(:)';
+ trgs(2,tmp) = tmp2(2:R,2:C)(:)';
+ trgs(3,tmp) = trgs(1,tmp) - R + 1 - tmp3 ;
+end # EOF "upper" triangulation
+
+#trgs = trgs(:,find(rem(1:R-1,2)'*rem(1:C-1,2)));
+
+
+if length (col) == 1 # Convert graylevel to RGB
+ col = [1 1 1]*col;
+
+elseif any (prod (size (col)) == [R*C,(R-1)*(C-1)])
+ col = [1;1;1]*col(:)';
+end
+
+if zgray || zrb || any (zcol(:)) # Treat zgray zrb and zcol options
+ zx = max (z(keepip));
+ zn = min (z(keepip));
+ if zgray, zcol = [0 0 0; 1 1 1]';
+ elseif zrb , zcol = [0 0 0.7; 0.5 0 0.8; 1 0 0]';
+ end
+
+ ci = 1 + floor (cw = (columns (zcol)-1) * (z(keepip) - zn)/(zx - zn));
+ cw = cw - ci + 1;
+ ii = find (ci >= columns (zcol));
+ if ! isempty (ii), ci(ii) = columns (zcol) - 1; cw(ii) = 1; end
+ col = zeros (3,R*C);
+ col(:,keepip) = \
+ zcol(:,ci) .* ([1;1;1]*(1-cw)) + zcol(:,ci+1) .* ([1;1;1]*cw);
+
+end # EOF zgray zrb and zcol options
+
+
+if checker && numel (col) <= 6
+ if isnan (checker), checker = 10; end
+ if length (checker) == 1, checker = [checker, checker]; end
+
+ col = checker_color (checker, col, R,C);
+
+ if 0
+ if checker(1) > 0, checker(1) = - (C-1)/checker(1); end
+ if checker(2) > 0, checker(2) = - (R-1)/checker(2); end
+
+ checker *= -1;
+ colx = 2 * (rem (0:C-2,2*checker(1)) < checker(1)) - 1;
+ coly = 2 * (rem (0:R-2,2*checker(2)) < checker(2)) - 1;
+ icol = 1 + ((coly'*colx) > 0);
+ # Keep at most 1st 2 colors of col for the
+ # checker
+ if prod (size (col)) == 2,
+ col = [1;1;1]*col;
+ elseif prod (size (col)) < 6, # Can't be < 3 because of previous code
+ col = col(1:3)(:);
+ if all (col >= 1-eps), col = [col [0;0;0]]; # Black and White
+ else col = [col [1;1;1]]; # X and White
+ end
+ end
+ col = reshape (col(:),3,2);
+ col = col(:,icol);
+ end
+end # EOF if checker
+
+
+if prod (size (col)) == 3*(R-1)*(C-1),
+ colorPerVertex = 0;
+end
+
+if ! colorPerVertex
+ if prod (size (col)) == 3*(R-1)*(C-1)
+ col = reshape (col,3, (R-1)*(C-1));
+ col = [col, col];
+ else
+ printf(["vrml_surf : ",\
+ " colorPerVertex==0, (R-1)*(C-1)==%i, but col has size [%i,%i]\n"],\
+ R*C,size (col));
+ end
+
+end
+
+if ! all(keepp),
+
+ # Try to toggle some triangles to fill in
+ # holes
+ if ! upper
+ nt = (R-1)*(C-1) ;
+ tmp = ! reshape(keepp(trgs),3,2*nt);
+ tmp = all( tmp == kron([0,0;0,1;1,0],ones(1,nt)) );
+ trgs(3, find ( tmp(1:nt) & rem (trgs(3,1:nt),R)) )++ ;
+ trgs(2, nt+ find ( tmp(nt+1:2*nt) & (rem (trgs(3,nt+1:2*nt),R)!=1)) )-- ;
+
+ # Remove whatever can't be kept
+ keept = all (reshape(keepp(trgs),3,2*(R-1)*(C-1)));
+ else
+ tmp = reshape (keepp,R,C);
+ keept = \
+ all (reshape (tmp(trgs(1:2,:)),2,2*(R-1)*(C-1))) & \
+ [(tmp(1:R-1,2:C) | tmp(2:R,2:C))(:)', \
+ (tmp(1:R-1,1:C-1) | tmp(2:R,1:C-1))(:)'] ;
+ end
+
+ keepit = find (keept);
+
+ renum = cumsum (keepp);
+
+ pts = pts (:,keepip);
+ trgs = reshape(renum (trgs (:,keepit)), 3, columns(keepit));
+
+ if prod (size (col)) == 6*(R-1)*(C-1)
+ col = col(:,keepit);
+ # Coherence check : colorPerVertex == 0
+ if colorPerVertex
+ error ("Col has size 3*(R-1)*(C-1), but colorPerVertex == 1");
+ end
+
+ elseif prod (size (col)) == 3*R*C
+ col = col(:,keepip);
+
+ # Coherence check : colorPerVertex == 1
+ if ! colorPerVertex
+ error ("Col has size 3*R*C, but colorPerVertex == 0");
+ end
+ end
+
+end
+## printf ("Calling vrml_faces\n");
+if !tex
+ s = vrml_faces (pts, trgs, "col", col,\
+ "colorPerVertex",colorPerVertex,\
+ "creaseAngle", creaseAngle,\
+ "tran", tran, "emit", emit,\
+ "DEFcoord",DEFcoord,"DEFcol",DEFcol);
+else
+ texXY = texXY(:,keepip);
+# texXY(:,[1:5,232:236])
+# pts(:,[1:5,232:236])
+# trgs(:,1:20)
+# [texXY; pts]
+# trgs
+# texXY(:,trgs(:))
+# R, C
+# keyboard
+ s = vrml_faces (pts, trgs,\
+ "tran", tran, "tex", tex, "tcoord", texXY,\
+ "DEFcoord",DEFcoord,"DEFcol",DEFcol);
+end
+## printf ("Done\n");
+## R=5; C=11;
+## x = ones(R,1)*[1:C]; y = [1:R]'*ones(1,C);
+## zz = z = sin(x)+(2*y/R-1).^2 ;
+## ## Punch some holes
+## holes = ind2sub ([R,C],[3,3,3,1,2,3,2,3;1,2,3,5,7,7,9,10]')
+## z(holes) = nan
+## save_vrml("tmp.wrl",vrml_surf(x,y,z+1))
+## save_vrml("tmp.wrl",vrml_surf(z,"col",[0.5,0,0],"tran",0.5),vrml_surf(z+1))
+
+endfunction
+