Mercurial > octave-nkf
view scripts/plot/appearance/specular.m @ 20266:83792dd9bcc1
Use in-place operators in m-files where possible.
* scripts/audio/@audioplayer/set.m, scripts/audio/@audiorecorder/set.m,
scripts/audio/mu2lin.m, scripts/elfun/cosd.m, scripts/general/del2.m,
scripts/general/profexplore.m, scripts/general/quadl.m, scripts/general/rat.m,
scripts/general/rotdim.m, scripts/help/get_first_help_sentence.m,
scripts/help/private/__strip_html_tags__.m, scripts/image/cubehelix.m,
scripts/io/textread.m, scripts/linear-algebra/duplication_matrix.m,
scripts/linear-algebra/housh.m, scripts/linear-algebra/krylov.m,
scripts/linear-algebra/logm.m, scripts/linear-algebra/normest.m,
scripts/linear-algebra/onenormest.m, scripts/optimization/fminsearch.m,
scripts/optimization/lsqnonneg.m, scripts/optimization/qp.m,
scripts/plot/appearance/annotation.m, scripts/plot/appearance/axis.m,
scripts/plot/appearance/legend.m, scripts/plot/appearance/specular.m,
scripts/plot/draw/colorbar.m, scripts/plot/draw/hist.m,
scripts/plot/draw/plotmatrix.m, scripts/plot/draw/private/__stem__.m,
scripts/plot/util/__actual_axis_position__.m,
scripts/plot/util/__gnuplot_drawnow__.m, scripts/plot/util/findobj.m,
scripts/plot/util/print.m, scripts/plot/util/private/__go_draw_axes__.m,
scripts/plot/util/private/__print_parse_opts__.m, scripts/plot/util/rotate.m,
scripts/polynomial/pchip.m, scripts/polynomial/polyaffine.m,
scripts/polynomial/polyder.m, scripts/polynomial/private/__splinefit__.m,
scripts/polynomial/residue.m, scripts/signal/arch_fit.m,
scripts/signal/arch_rnd.m, scripts/signal/bartlett.m,
scripts/signal/blackman.m, scripts/signal/freqz.m, scripts/signal/hamming.m,
scripts/signal/hanning.m, scripts/signal/spectral_adf.m,
scripts/signal/spectral_xdf.m, scripts/signal/stft.m,
scripts/sparse/bicgstab.m, scripts/sparse/cgs.m,
scripts/sparse/private/__sprand_impl__.m, scripts/sparse/qmr.m,
scripts/sparse/sprandsym.m, scripts/sparse/svds.m, scripts/specfun/legendre.m,
scripts/special-matrix/gallery.m, scripts/statistics/base/gls.m,
scripts/statistics/models/logistic_regression.m,
scripts/statistics/tests/kruskal_wallis_test.m,
scripts/statistics/tests/manova.m, scripts/statistics/tests/wilcoxon_test.m,
scripts/time/datevec.m:
Use in-place operators in m-files where possible.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 26 May 2015 21:07:42 -0700 |
parents | 4197fc428c7d |
children |
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## Copyright (C) 2009-2015 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} {} specular (@var{sx}, @var{sy}, @var{sz}, @var{lv}, @var{vv}) ## @deftypefnx {Function File} {} specular (@var{sx}, @var{sy}, @var{sz}, @var{lv}, @var{vv}, @var{se}) ## Calculate the specular reflection strength of a surface defined by the ## normal vector elements @var{sx}, @var{sy}, @var{sz} using Phong's ## approximation. ## ## The light source location and viewer location vectors are specified using ## parameters @var{lv} and @var{vv} respectively. The location vectors can ## given as 2-element vectors [azimuth, elevation] in degrees or as 3-element ## vectors [x, y, z]. ## ## An optional sixth argument specifies the specular exponent (spread) @var{se}. ## If not given, @var{se} defaults to 10. ## @seealso{diffuse, surfl} ## @end deftypefn ## Author: Kai Habel <kai.habel@gmx.de> function retval = specular (sx, sy, sz, lv, vv, se) if (nargin < 5 || nargin > 6) print_usage (); endif ## Check normal vectors if (! size_equal (sx, sy, sz)) error ("specular: SX, SY, and SZ must be the same size"); endif ## Check light vector (lv) argument if (! isvector (lv) || length (lv) < 2 || length (lv) > 3) error ("specular: 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 ## Check view vector (vv) argument if (! isvector (vv) || length (vv) < 2 || length (lv) > 3) error ("specular: view vector VV must be a 2- or 3-element vector"); elseif (length (vv) == 2) [vv(1), vv(2), vv(3)] = sph2cart (vv(1) * pi / 180, vv(2) * pi / 180, 1.0); endif ## Check specular exponent (se) argument if (nargin < 6) se = 10; elseif (! (isnumeric (se) && numel (se) == 1 && se > 0)) error ("specular: exponent SE must be a positive scalar"); endif ## Normalize view and light vectors if (sum (abs (lv)) > 0) lv /= norm (lv); endif if (sum (abs (vv)) > 0) vv /= norm (vv); endif ## Calculate normal vector lengths and dot-products ns = sqrt (sx.^2 + sy.^2 + sz.^2); l_dot_n = (sx * lv(1) + sy * lv(2) + sz * lv(3)) ./ ns; v_dot_n = (sx * vv(1) + sy * vv(2) + sz * vv(3)) ./ ns; ## Calculate specular reflection using Phong's approximation retval = 2 * l_dot_n .* v_dot_n - dot (lv, vv); ## Set reflectance to zero if light is on the other side retval(l_dot_n < 0) = 0; ## Allow postive values only retval(retval < 0) = 0; retval .^= se; endfunction