star-line

commit 70df096314ca59941e4b1aa38fb02775b6e46704
parent 132c1678ad05eb3fd56b3c78fba680eeff4441f4
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Wed, 15 Apr 2026 15:29:25 +0200

sln-build: Added an option to collapse polylines

This option allows to use the algorithm that constructs polylines
from internal nodes by successively grouping their child polylines in
pairs.

Diffstat:
M
doc/sln-build.1
 | 
16
++++++++++++++--
M
src/sln_build.c
 | 
8
++++++--

2 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/doc/sln-build.1 b/doc/sln-build.1
@@ -15,7 +15,7 @@
 .\"
 .\" You should have received a copy of the GNU General Public License
 .\" along with this program. If not, see <http://www.gnu.org/licenses/>.
-.Dd April 8, 2026
+.Dd April 15, 2026
 .Dt SLN-BUILD 1
 .Os
 .\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
@@ -25,7 +25,7 @@
 .\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .Sh SYNOPSIS
 .Nm
-.Op Fl hsv
+.Op Fl chsv
 .Op Fl a Ar arity
 .Op Fl e Ar polyline_opt Ns Op : Ns Ar polyline_opt No ...
 .Op Fl l Ar line_profile
@@ -56,6 +56,18 @@ Maximum number of children of an internal node in the constructed tree
 that partitions the input lines.
 It cannot be less than 2, which is its default value.
 .\""""""""""""""""""""""""""""""""""
+.It Fl c
+For each internal node, construct its polyline by merging the polylines
+of its children in pairs and then simplifying the result of this merge.
+The process is repeated on the resulting polylines until only a single
+polyline remains, which becomes the polyline of the internal node.
+In other words, these polylines are constructed by successively
+collapsing the polylines of the child nodes.
+.Pp
+By default, the polylines of the internal nodes are constructed in a
+single step of merging and simplification that takes into account all
+child polylines at once.
+.\""""""""""""""""""""""""""""""""""
 .It Fl e Ar polyline_opt Ns Op : Ns Ar polyline_opt No ...
 Configure the polylines, i.e., the data used to encode the shape of the
 spectrum in the acceleration structure.
diff --git a/src/sln_build.c b/src/sln_build.c
@@ -51,6 +51,7 @@ struct args {
   double mesh_decimation_err;
   unsigned nvertices_hint;
   enum sln_mesh_type mesh_type;
+  int collapse_polylines;
 
   /* Miscellaneous */
   int quit;
@@ -75,6 +76,7 @@ struct args {
   0.01,                                                                        \
   16,                                                                          \
   SLN_MESH_UPPER,                                                              \
+  0,                                                                           \
                                                                                \
   /* Miscellaneous */                                                          \
   0, /* Quit */                                                                \
@@ -105,7 +107,7 @@ static void
 usage(FILE* stream)
 {
   fprintf(stream,
-"usage: sln-build [-hsv] [-a arity] [-e polyline_opt[:polyline_opt ...]]\n"
+"usage: sln-build [-chsv] [-a arity] [-e polyline_opt[:polyline_opt ...]]\n"
 "                 [-l line_profile] [-o accel_struct] -P pressure -T temperature\n"
 "                 -m molparams -x mixture [lines]\n");
 }
@@ -225,12 +227,13 @@ args_init(struct args* args, int argc, char** argv)
 
   *args = ARGS_DEFAULT;
 
-  while((opt = getopt(argc, argv, "a:e:hl:o:P:sT:m:vx:")) != -1) {
+  while((opt = getopt(argc, argv, "a:ce:hl:o:P:sT:m:vx:")) != -1) {
     switch(opt) {
       case 'a':
         res = cstr_to_uint(optarg, &args->arity);
         if(res == RES_OK && args->arity < 2) res = RES_BAD_ARG;
         break;
+      case 'c': args->collapse_polylines = 1; break;
       case 'e':
         res = cstr_parse_list(optarg, ':', parse_polyline_opt, args);
         break;
@@ -449,6 +452,7 @@ cmd_run(struct cmd* cmd)
   tree_args.mesh_decimation_err = cmd->args.mesh_decimation_err;
   tree_args.mesh_type = cmd->args.mesh_type;
   tree_args.arity = cmd->args.arity;
+  tree_args.collapse_polylines = cmd->args.collapse_polylines;
 
   if(cmd->args.output) {
     write_args.filename = cmd->args.output;