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view scripts/plot/draw/reducepatch.m @ 27918:b442ec6dda5c
use centralized file for copyright info for individual contributors
* COPYRIGHT.md: New file.
* In most other files, use "Copyright (C) YYYY-YYYY The Octave Project
Developers" instead of tracking individual names in separate source
files. The motivation is to reduce the effort required to update the
notices each year.
Until now, the Octave source files contained copyright notices that
list individual contributors. I adopted these file-scope copyright
notices because that is what everyone was doing 30 years ago in the
days before distributed version control systems. But now, with many
contributors and modern version control systems, having these
file-scope copyright notices causes trouble when we update copyright
years or refactor code.
Over time, the file-scope copyright notices may become outdated as new
contributions are made or code is moved from one file to
another. Sometimes people contribute significant patches but do not
add a line claiming copyright. Other times, people add a copyright
notice for their contribution but then a later refactoring moves part
or all of their contribution to another file and the notice is not
moved with the code. As a practical matter, moving such notices is
difficult -- determining what parts are due to a particular
contributor requires a time-consuming search through the project
history. Even managing the yearly update of copyright years is
problematic. We have some contributors who are no longer
living. Should we update the copyright dates for their contributions
when we release new versions? Probably not, but we do still want to
claim copyright for the project as a whole.
To minimize the difficulty of maintaining the copyright notices, I
would like to change Octave's sources to use what is described here:
https://softwarefreedom.org/resources/2012/ManagingCopyrightInformation.html
in the section "Maintaining centralized copyright notices":
The centralized notice approach consolidates all copyright
notices in a single location, usually a top-level file.
This file should contain all of the copyright notices
provided project contributors, unless the contribution was
clearly insignificant. It may also credit -- without a copyright
notice -- anyone who helped with the project but did not
contribute code or other copyrighted material.
This approach captures less information about contributions
within individual files, recognizing that the DVCS is better
equipped to record those details. As we mentioned before, it
does have one disadvantage as compared to the file-scope
approach: if a single file is separated from the distribution,
the recipient won't see the contributors' copyright notices.
But this can be easily remedied by including a single
copyright notice in each file's header, pointing to the
top-level file:
Copyright YYYY-YYYY The Octave Project Developers
See the COPYRIGHT file at the top-level directory
of this distribution or at https://octave.org/COPYRIGHT.html.
followed by the usual GPL copyright statement.
For more background, see the discussion here:
https://lists.gnu.org/archive/html/octave-maintainers/2020-01/msg00009.html
Most files in the following directories have been skipped intentinally
in this changeset:
doc
libgui/qterminal
liboctave/external
m4
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Mon, 06 Jan 2020 15:38:17 -0500 |
parents | f2bb4f2093b9 |
children | 1891570abac8 |
line wrap: on
line source
## Copyright (C) 2016-2019 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this distribution ## or <https://octave.org/COPYRIGHT.html/>. ## ## ## 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 ## <https://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {} {@var{reduced_fv} =} reducepatch (@var{fv}) ## @deftypefnx {} {@var{reduced_fv} =} reducepatch (@var{faces}, @var{vertices}) ## @deftypefnx {} {@var{reduced_fv} =} reducepatch (@var{patch_handle}) ## @deftypefnx {} {} reducepatch (@var{patch_handle}) ## @deftypefnx {} {@var{reduced_fv} =} reducepatch (@dots{}, @var{reduction_factor}) ## @deftypefnx {} {@var{reduced_fv} =} reducepatch (@dots{}, "fast") ## @deftypefnx {} {@var{reduced_fv} =} reducepatch (@dots{}, "verbose") ## @deftypefnx {} {[@var{reduced_faces}, @var{reduces_vertices}] =} reducepatch (@dots{}) ## ## Reduce the number of faces and vertices in a patch object while retaining ## the overall shape of the patch. ## ## The input patch can be represented by a structure @var{fv} with the ## fields @code{faces} and @code{vertices}, by two matrices @var{faces} and ## @var{vertices} (see, e.g., the result of @code{isosurface}), or by a ## handle to a patch object @var{patch_handle} (@pxref{XREFpatch,,patch}). ## ## The number of faces and vertices in the patch is reduced by iteratively ## collapsing the shortest edge of the patch to its midpoint (as discussed, ## e.g., here: ## @url{https://libigl.github.io/libigl/tutorial/tutorial.html#meshdecimation}). ## ## Currently, only patches consisting of triangles are supported. The ## resulting patch also consists only of triangles. ## ## If @code{reducepatch} is called with a handle to a valid patch ## @var{patch_handle}, and without any output arguments, then the given ## patch is updated immediately. ## ## If the @var{reduction_factor} is omitted, the resulting structure ## @var{reduced_fv} includes approximately 50% of the faces of the original ## patch. If @var{reduction_factor} is a fraction between 0 (excluded) and 1 ## (excluded), a patch with approximately the corresponding fraction of faces ## is determined. ## If @var{reduction_factor} is an integer greater than or equal to 1, the ## resulting patch has approximately @var{reduction_factor} faces. Depending ## on the geometry of the patch, the resulting number of faces can differ from ## the given value of @var{reduction_factor}. This is especially true when ## many shared vertices are detected. ## ## For the reduction, it is necessary that vertices of touching faces are ## shared. Shared vertices are detected automatically. This detection can be ## skipped by passing the optional string argument @qcode{"fast"}. ## ## With the optional string arguments @qcode{"verbose"}, additional status ## messages are printed to the command window. ## ## Any string input arguments must be passed after all other arguments. ## ## If called with one output argument, the reduced faces and vertices are ## returned in a structure @var{reduced_fv} with the fields @code{faces} and ## @code{vertices} (see the one output option of @code{isosurface}). ## ## If called with two output arguments, the reduced faces and vertices are ## returned in two separate matrices @var{reduced_faces} and ## @var{reduced_vertices}. ## ## @seealso{isosurface, isonormals, reducevolume, patch} ## @end deftypefn ## Author: mmuetzel ## FIXME: Convert faces to only triangles if necessary function varargout = reducepatch (varargin) if (nargin < 1 || nargin > 5) print_usage (); endif [faces, vertices, max_faces, patch_handle, fast, verbose] = ... __get_check_reducepatch_args__ (varargin{:}); if (verbose) printf (["reducepatch: before reduction of faces: ", ... "%5d faces, %5d vertices\n"], rows (faces), rows (vertices)); endif if (max_faces >= rows (faces)) faces_reduced = faces; vertices_reduced = vertices; else if (! fast) [faces, vertices] = __unite_shared_vertices__ (faces, vertices); if (verbose) printf (["reducepatch: after detection of shared vertices: ", ... "%5d faces, %5d vertices\n"], rows (faces), rows (vertices)); endif endif [faces_reduced, vertices_reduced] = ... __reducepatch__ (vertices, faces, max_faces, verbose); endif if (verbose) printf (["reducepatch: after reduction of faces: ", ... "%5d faces, %5d vertices\n"], ... rows (faces_reduced), rows (vertices_reduced)); endif ## output if (! isempty (patch_handle) && nargout == 0) ## update patch object set (patch_handle, "Faces", faces_reduced, "Vertices", vertices_reduced); elseif (nargout == 2) # faces, vertices varargout{1} = faces_reduced; varargout{2} = vertices_reduced; else # fv structure varargout{1}.faces = faces_reduced; varargout{1}.vertices = vertices_reduced; endif endfunction ## assign input parameters and check their validity function [faces, vertices, max_faces, patch_handle, fast, verbose] = ... __get_check_reducepatch_args__ (varargin) ## default values faces = vertices = max_faces = patch_handle = []; reduction_factor = 0.5; fast = verbose = false; num_string_inputs = 0; ## check whether last 2 input arguments are strings and assign parameters valid_vals = nargin:-1:nargin-1; valid_vals(valid_vals < 1) = []; for arg = varargin(valid_vals) if (! ischar (arg{1})) break; # no string arguments at end, exit checking endif switch (tolower (arg{1})) case {"f", "fast"} fast = true; num_string_inputs += 1; case {"v", "verbose"} verbose = true; num_string_inputs += 1; case "" num_string_inputs++; ## silently ignore empty strings otherwise error ("reducepatch: parameter '%s' not supported", arg{1}); endswitch endfor ## get faces and vertices i_fv = 1; arg1 = varargin{1}; if (isstruct (arg1)) if (all (isfield (arg1, {"vertices", "faces"}))) vertices = arg1.vertices; faces = arg1.faces; else error (["reducepatch: struct FV must contain the fields ", ... "'vertices' and 'faces'."]); endif elseif (isscalar (arg1)) patch_handle = arg1; if (isgraphics (patch_handle, "patch")) vertices = get (patch_handle, "Vertices"); faces = get (patch_handle, "Faces"); else error ("reducepatch: PATCH_HANDLE must be a valid handle to a patch"); endif elseif (ismatrix (arg1)) faces = arg1; if (nargin - num_string_inputs > 1 && ismatrix (varargin{2})) vertices = varargin{2}; i_fv = 2; else error (["reducepatch: If first argument is a matrix containing ", ... "FACES, second argument must be a matrix containing VERTICES"]); endif else print_usage ("reducepatch"); endif ## get reduction_factor if (nargin - num_string_inputs > i_fv) reduction_factor = varargin{i_fv + 1}; if (! isscalar (reduction_factor) || reduction_factor <= 0) error ("reducepatch: REDUCTION_FACTOR must be a positive scalar"); endif endif ## check faces and vertices if (columns (vertices) != 3) error ("reducepatch: VERTICES must be an Mx3 matrix"); endif if (columns (faces) != 3) ## FIXME: Convert faces to only triangles if necessary error ("reducepatch: Currently patches must consist of triangles only"); endif if (any (mod (faces(:), 1)) || any (faces(:) < 1)) error ("reducepatch: FACES must consist of positive integer indices only"); endif if (max (faces(:)) > rows (vertices)) error ("reducepatch: not enough VERTICES for given FACES"); endif ## get max_faces num_faces = rows (faces); if (reduction_factor < 1) max_faces = floor (num_faces * reduction_factor); else max_faces = reduction_factor; endif endfunction ## actual function to reduce number of faces function [faces_reduced, vertices_reduced] = ... __reducepatch__ (vertices, faces, max_faces, verbose) num_faces = rows (faces); faces = sort (faces, 2); ## get all unique edges all_edges = sort ([faces(:,1) faces(:,2); faces(:,2) faces(:,3); faces(:,3) faces(:,1)], 2); edges = unique (all_edges, "rows"); num_edges = rows (edges); ## calculate length of edges edge_length = norm (vertices(edges(:,1),:) - vertices(edges(:,2),:), ... 2, "rows"); if (verbose) printf ("reducepatch: reducing number of faces"); ## do not spam the command window with dots if many faces are collapsed verbose_stepwidth = (num_faces - max_faces) / 100; # max. 100 dots verbose_counter = 0; endif ## reduce number of faces clean_finish = true; do ## find shortest edge i_shortest_edge = find (edge_length == min (edge_length), 1, "first"); if (any (isinf (vertices(edges(i_shortest_edge,:),:)))) warning (["reducepatch: shortest edge is marked as deleted. ", ... "This should never happen."]) clean_finish = false; break; endif start_point_idx = edges(i_shortest_edge,1); end_point_idx = edges(i_shortest_edge,2); ## collapse the edge to its midpoint vertices(start_point_idx,:) = 0.5 * ... (vertices(start_point_idx,:) + vertices(end_point_idx,:)); ## endpoint will be deleted later ## remove collapsed edge info edges(i_shortest_edge,:) = []; edge_length(i_shortest_edge) = []; ## unite collapsed edges of neighboring faces to one edge faces_with_collapsed_edge = any (faces == start_point_idx, 2) & ... any (faces == end_point_idx, 2); edges_of_collapsed_faces = faces(faces_with_collapsed_edge,:); ## get other vertex of collapsed faces third_vertices = ... edges_of_collapsed_faces(... faces(faces_with_collapsed_edge,:) != start_point_idx & ... faces(faces_with_collapsed_edge,:) != end_point_idx); if (! isempty (third_vertices)) ## delete edge of the collapsed faces which also has end_point ## (keep the one with start_point) edges_to_delete = any (edges == end_point_idx, 2) & ... any (any (bsxfun (@eq, edges, ... reshape (third_vertices, 1, 1, [])), 3), 2); edges(edges_to_delete,:) = []; edge_length(edges_to_delete) = []; endif ## mark the faces that collapsed for later removal faces(faces_with_collapsed_edge,:) = Inf; ## update the lengths of the moved edges edges_with_moved_point = any (edges == start_point_idx, 2); edge_length(edges_with_moved_point) = ... norm (vertices(edges(edges_with_moved_point,1),:) - ... vertices(edges(edges_with_moved_point,2),:), 2, "rows"); ## replace all vertices that use end_point to use start_point if (start_point_idx != end_point_idx) edges(edges == end_point_idx) = start_point_idx; faces(faces == end_point_idx) = start_point_idx; vertices(end_point_idx,:) = Inf; # mark vertex for later removal endif ## Pretty print a row of dots while performing calulation if (verbose && ++verbose_counter > verbose_stepwidth) printf ("."); verbose_counter = 0; endif until (max_faces > num_faces - sum (isinf (faces(:,1)))) if (verbose) printf ("\n"); endif if (! clean_finish) ## FIXME: What should be done in this case? ## continue anyway? endif ## finally, remove vertices and faces removed_vertices = isinf (vertices(:,1)); vertices_reduced = vertices(! removed_vertices,:); faces_reduced = faces(! isinf (faces(:,1)),:); ## renumber vertices in faces with subsequent numbers vertex_renum = ones (rows (vertices), 1); vertex_renum(removed_vertices) = 0; vertex_renum = cumsum (vertex_renum); faces_reduced = vertex_renum(faces_reduced); endfunction %!demo %! clf; %! [x,y,z] = meshgrid (-2:0.5:2, -2:0.5:2, -2:0.5:2); %! val = x.^2 + y.^2 + z.^2; %! fv = isosurface (x, y, z, val, 1); %! ax1 = subplot (1, 2, 1); %! patch (fv, "FaceColor", "g"); %! view (3); axis equal; %! title ("Sphere with all faces"); %! ax2 = subplot(1, 2, 2); %! patch (reducepatch (fv, 72), "FaceColor", "g"); %! view (3); axis equal; %! title ("Sphere with reduced number of faces"); %! linkprop ([ax1, ax2], {"CameraPosition", "CameraUpVector"}); %!shared faces, vertices, fv, num_faces %! [x,y,z] = meshgrid (-2:0.5:2, -2:0.5:2, -2:0.5:2); %! val = x.^2 + y.^2 + z.^2; %! [faces, vertices] = isosurface (x, y, z, val, 1); %! fv.faces = faces; fv.vertices = vertices; %! num_faces = rows (faces); ## one input (structure), one output %!test %! fv_reduced = reducepatch (fv); %! assert (size (fv_reduced.faces, 1), num_faces * .5, 3); %! assert (size (fv_reduced.faces, 2), 3); %! assert (size (fv_reduced.vertices, 2), 3); ## two inputs (faces, vertices), one output %!test %! fv_reduced = reducepatch (faces, vertices); %! assert (size (fv_reduced.faces, 1), num_faces * .5, 3); %! assert (size (fv_reduced.faces, 2), 3); %! assert (size (fv_reduced.vertices, 2), 3); ## two inputs (structure, reduction_factor > 1), two outputs %!test %! [faces_reduced, vertices_reduced] = reducepatch (fv, 20); %! assert (size (faces_reduced, 1), 20, 3); %! assert (size (faces_reduced, 2), 3); %! assert (size (vertices_reduced, 2), 3); ## three inputs (faces, vertices, reduction_factor < 1), two outputs %!test %! [faces_reduced, vertices_reduced] = reducepatch (faces, vertices, .5); %! assert (size (faces_reduced, 1), num_faces * .5, 3); %! assert (size (faces_reduced, 2), 3); %! assert (size (vertices_reduced, 2), 3); ## two inputs (structure, reduction_factor < 1) + one string, no outputs ## (update patch object in figure) %!test %! h_fig = figure ("visible", "off"); %! p = patch (fv); %! reducepatch (p, .35, "f"); %! assert (size (get (p, "Faces"), 1), num_faces * .35, 3); %! assert (size (get (p, "Faces"), 2), 3); %! assert (size (get (p, "Vertices"), 2), 3); %! close (h_fig); ## three inputs (faces, vertices, reduction_factor > 1) + one empty ## string, one output %!test %! fv_reduced = reducepatch (faces, vertices, 52, ""); %! assert (size (fv_reduced.faces, 1), 52, 3); %! assert (size (fv_reduced.faces, 2), 3); %! assert (size (fv_reduced.vertices, 2), 3); ## two inputs (structure, reduction_factor < 1) + one string, two outputs %!test %! [faces_reduced, vertices_reduced] = reducepatch (fv, .4, "fast"); %! assert (size (faces_reduced, 1), num_faces * .4, 3); %! assert (size (faces_reduced, 2), 3); %! assert (size (vertices_reduced, 2), 3); ## one input (structure) + two (empty) strings, two outputs %!test %! [faces_reduced, vertices_reduced] = reducepatch (fv, "f", ""); %! assert (size (faces_reduced, 1), num_faces * .5, 3); %! assert (size (faces_reduced, 2), 3); %! assert (size (vertices_reduced, 2), 3); ## test for each error %!error reducepatch () %!error reducepatch (fv, faces, vertices, .5, "f", "v") %!error <reducepatch: parameter 'foo' not supported> %! fv_reduced = reducepatch (faces, vertices, .7, "foo"); %!error <struct FV must contain the fields 'vertices' and 'faces'> %! fv_incomplete.faces = faces; %! reducepatch (fv_incomplete, .7); %!error <PATCH_HANDLE must be a valid handle to a patch> reducepatch (pi, .7) %!error <If first argument is a matrix containing FACES, second argument must be a matrix containing VERTICES> reducepatch (faces) %!error <REDUCTION_FACTOR must be a positive scalar> reducepatch (fv, [.7 .5]) %!error <REDUCTION_FACTOR must be a positive scalar> reducepatch (fv, -5) %!error <VERTICES must be an Mx3 matrix> reducepatch (faces, .7, "v") %!error <reducepatch: Currently patches must consist of triangles only> %! faces_new = NaN (size (faces, 1), 4); %! faces_new(:,1:3) = faces; %! faces_new(1,4) = 5; %! reducepatch (faces_new, vertices); %!error <reducepatch: not enough VERTICES for given FACES> %! faces_new = faces; %! faces_new(1,3) = size (vertices, 1) + 1; %! reducepatch (faces_new, vertices);