Implemented TriangleMesh->merge

xs/src/TriangleMesh.cpp

@@ -525,4 +525,23 @@ TriangleMesh::split() const
     return meshes;
 }
 
+void
+TriangleMesh::merge(const TriangleMesh* mesh)
+{
+    // reset stats and metadata
+    int number_of_facets = this->stl.stats.number_of_facets;
+    stl_initialize(&this->stl);
+    stl_invalidate_shared_vertices(&this->stl);
+    
+    // update facet count and allocate more memory
+    this->stl.stats.number_of_facets = number_of_facets + mesh->stl.stats.number_of_facets;
+    this->stl.stats.original_num_facets = this->stl.stats.number_of_facets;
+    stl_reallocate(&this->stl);
+    
+    // copy facets
+    for (int i = 0; i < mesh->stl.stats.number_of_facets; i++) {
+        this->stl.facet_start[number_of_facets + i] = mesh->stl.facet_start[i];
+    }
+}
+
 }

xs/src/TriangleMesh.hpp

@@ -28,6 +28,7 @@ class TriangleMesh
     void rotate(double angle, Point* center);
     std::vector<Polygons>* slice(const std::vector<double> &z);
     TriangleMeshPtrs split() const;
+    void merge(const TriangleMesh* mesh);
     stl_file stl;
 };
 

xs/src/admesh/stl.h

@@ -178,7 +178,7 @@ static void stl_count_facets(stl_file *stl, char *file);
 extern void stl_allocate(stl_file *stl);
 static void stl_read(stl_file *stl, int first_facet, int first);
 static void stl_facet_stats(stl_file *stl, stl_facet facet, int first);
-static void stl_reallocate(stl_file *stl);
+extern void stl_reallocate(stl_file *stl);
 static int stl_get_little_int(FILE *fp);
 static float stl_get_little_float(FILE *fp);
 extern void stl_get_size(stl_file *stl);

xs/src/admesh/stlinit.c

@@ -213,7 +213,7 @@ stl_open_merge(stl_file *stl, char *file)
   stl_read(stl, first_facet, 0);
 }
 
-static void
+extern void
 stl_reallocate(stl_file *stl)
 {
   /*  Reallocate more memory for the .STL file(s) */

xs/t/01_trianglemesh.t

@@ -4,7 +4,7 @@ use strict;
 use warnings;
 
 use Slic3r::XS;
-use Test::More tests => 45;
+use Test::More tests => 46;
 
 is Slic3r::TriangleMesh::XS::hello_world(), 'Hello world!',
     'hello world';
@@ -46,6 +46,11 @@ my $cube = {
     my $result = $m->split;
     is scalar(@$result), 1, 'split';
     isa_ok $result->[0], 'Slic3r::TriangleMesh::XS', 'split';
+    
+    my $m2 = Slic3r::TriangleMesh::XS->new;
+    $m2->ReadFromPerl($cube->{vertices}, $cube->{facets});
+    $m->merge($m2);
+    is $m->stats->{number_of_facets}, 2 * $m2->stats->{number_of_facets}, 'merge';
 }
 
 {

xs/xsp/TriangleMesh.xsp

@@ -17,6 +17,7 @@
     void align_to_origin();
     void rotate(double angle, Point* center);
     TriangleMeshPtrs split();
+    void merge(TriangleMesh* mesh);
 %{
 
 SV*