maint: untabify and remove trailing whitespace from source files * bicg.m, gmres.m, pkg.m: Untabify and remove trailing whitespace. * libcruft/Makefile.am, libcruft/blas-xtra/cdotc3.f, libcruft/blas-xtra/cmatm3.f, libcruft/blas-xtra/ddot3.f, libcruft/blas-xtra/dmatm3.f, libcruft/blas-xtra/sdot3.f, libcruft/blas-xtra/smatm3.f, libcruft/blas-xtra/zdotc3.f, libcruft/blas-xtra/zmatm3.f, libcruft/lapack-xtra/crsf2csf.f, libcruft/lapack-xtra/zrsf2csf.f, liboctave/Array.cc, liboctave/DASPK-opts.in, liboctave/DASRT-opts.in, liboctave/DASSL-opts.in, liboctave/LSODE-opts.in, liboctave/Makefile.a,mliboctave/Quad-opts.in, liboctave/Sparse-perm-op-defs.h, scripts/Makefile.a,mscripts/deprecated/glpkmex.m, scripts/general/blkdiag.m, scripts/general/interp1.m, scripts/general/profshow.m, scripts/general/quadl.m, scripts/general/triplequad.m, scripts/help/__makeinfo__.m, scripts/io/strread.m, scripts/io/textread.m, scripts/io/textscan.m, scripts/linear-algebra/rank.m, scripts/miscellaneous/gzip.m, scripts/miscellaneous/private/__xzip__.m, scripts/miscellaneous/tempdir.m, scripts/miscellaneous/unpack.m, scripts/pkg/pkg.m, scripts/plot/allchild.m, scripts/plot/ancestor.m, scripts/plot/cla.m, scripts/plot/clf.m, scripts/plot/findall.m, scripts/plot/findobj.m, scripts/plot/gca.m, scripts/plot/gcf.m, scripts/plot/hggroup.m, scripts/plot/isfigure.m, scripts/plot/ishghandle.m, scripts/plot/legend.m, scripts/plot/line.m, scripts/plot/loglog.m, scripts/plot/patch.m, scripts/plot/print.m, scripts/plot/private/__quiver__.m, scripts/plot/private/__scatter__.m, scripts/plot/rectangle.m, scripts/plot/semilogx.m, scripts/plot/semilogy.m, scripts/plot/surface.m, scripts/plot/text.m, scripts/plot/title.m, scripts/plot/trisurf.m, scripts/plot/view.m, scripts/plot/whitebg.m, scripts/plot/xlabel.m, scripts/plot/xlim.m, scripts/plot/ylabel.m, scripts/plot/ylim.m, scripts/plot/zlabel.m, scripts/plot/zlim.m, scripts/polynomial/mkpp.m, scripts/polynomial/polygcd.m, scripts/polynomial/ppint.m, scripts/polynomial/ppjumps.m, scripts/polynomial/ppval.m, scripts/set/setxor.m, scripts/sparse/bicgstab.m, scripts/sparse/cgs.m, scripts/sparse/spconvert.m, scripts/specfun/nthroot.m, scripts/strings/strmatch.m, scripts/strings/untabify.m, scripts/testfun/demo.m, scripts/testfun/example.m, src/DLD-FUNCTIONS/filter.cc, src/DLD-FUNCTIONS/mgorth.cc, src/DLD-FUNCTIONS/quadcc.cc, src/DLD-FUNCTIONS/str2double.cc, src/Makefile.a,msrc/gl-render.cc, src/gl2ps-renderer.cc, src/graphics.cc, src/octave-config.cc.in, src/octave-config.in, src/ov-class.h, src/ov-fcn.h, src/profiler.cc, src/profiler.h, src/pt-binop.cc, src/pt-unop.cc, src/symtab.cc, src/txt-eng-ft.cc: Remove trailing whitespace.

## Copyright (C) 2009-2011 Kai Habel
##
## This file is part of Octave.
##
## Octave 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.
##
## Octave 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 Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} diffuse (@var{sx}, @var{sy}, @var{sz}, @var{lv})
## Calculate diffuse reflection strength of a surface defined by the normal
## vector elements @var{sx}, @var{sy}, @var{sz}.
## The light vector can be specified using parameter @var{lv}.  It can be
## given as 2-element vector [azimuth, elevation] in degrees or as 3-element
## vector [lx, ly, lz].
## @seealso{specular, surfl}
## @end deftypefn

## Author: Kai Habel <kai.habel@gmx.de>

function retval = diffuse (sx, sy, sz, lv)

  if (nargin != 4)
    print_usage ();
  endif

  ## check for normal vector
  if (!size_equal (sx, sy, sz))
    error ("diffuse: SX, SY, and SZ must have same size");
  endif

  ## check for light vector (lv) argument
  if (length (lv) < 2 || length (lv) > 3)
    error ("diffuse: light vector LV must be a 2- or 3-element vector");
  elseif (length (lv) == 2)
    [lv(1), lv(2), lv(3)] = sph2cart (lv(1) * pi/180, lv(2) * pi/180, 1.0);
  endif

  ## Normalize view and light vector.
  if (sum (abs (lv)) > 0)
    lv  /= norm (lv);
  endif

  ns = sqrt (sx.^2 + sy.^2 + sz.^2);
  retval = (sx * lv(1) + sy * lv(2) + sz * lv(3)) ./ ns;
  retval(retval < 0) = 0;

endfunction