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[CreaPhase.git] / octave_packages / nurbs-1.3.6 / private / nrb_srf_basisfun__.m

diff --git a/octave_packages/nurbs-1.3.6/private/nrb_srf_basisfun__.m b/octave_packages/nurbs-1.3.6/private/nrb_srf_basisfun__.m
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+++ b/octave_packages/nurbs-1.3.6/private/nrb_srf_basisfun__.m
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+function [B, N] = nrb_srf_basisfun__ (points, nrb);
+
+%  __NRB_SRF_BASISFUN__: Undocumented internal function
+%
+%   Copyright (C) 2009 Carlo de Falco
+%   This software comes with ABSOLUTELY NO WARRANTY; see the file
+%   COPYING for details.  This is free software, and you are welcome
+%   to distribute it under the conditions laid out in COPYING.
+
+    m    = size (nrb.coefs, 2) -1;
+    n    = size (nrb.coefs, 3) -1;
+    
+    p    = nrb.order(1) -1;
+    q    = nrb.order(2) -1;
+
+    u = points(1,:);
+    v = points(2,:);
+    npt = length(u);
+
+    U    = nrb.knots{1};
+    V    = nrb.knots{2};
+    
+    w    = squeeze(nrb.coefs(4,:,:));
+
+    spu    = findspan (m, p, u, U); 
+    spv    = findspan (n, q, v, V);
+    NuIkuk = basisfun (spu, u, p, U);
+    NvJkvk = basisfun (spv, v, q, V);
+
+    indIkJk = nrbnumbasisfun (points, nrb);
+
+    for k=1:npt
+      wIkaJkb(1:p+1, 1:q+1) = reshape (w(indIkJk(k, :)), p+1, q+1); 
+      NuIkukaNvJkvk(1:p+1, 1:q+1) = (NuIkuk(k, :).' * NvJkvk(k, :));
+      RIkJk(k, :) = reshape((NuIkukaNvJkvk .* wIkaJkb ./ sum(sum(NuIkukaNvJkvk .* wIkaJkb))),1,[]);
+    end
+    
+    B = RIkJk;
+    N = indIkJk;
+    
+  end
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