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More porting work
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@alranel
alranel committed Sep 7, 2013
1 parent 5adb187 commit 46bd407
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Showing 3 changed files with 131 additions and 46 deletions.
163 changes: 120 additions & 43 deletions xs/src/TriangleMesh.cpp
View file
Expand Up @@ -207,39 +207,15 @@ TriangleMesh::slice(const std::vector<double> &z)
std::vector<IntersectionLines> lines(z.size());

for (int facet_idx = 0; facet_idx < this->stl.stats.number_of_facets; facet_idx++) {
stl_facet facet = this->stl.facet_start[facet_idx]; // this is a copy

/* reorder vertices so that the first one is the one with lowest Z
this is needed to get all intersection lines in a consistent order
(external on the right of the line) */
/*
float min_z;
if (facet.vertex[1].z < facet.vertex[0].z && facet.vertex[1].z < facet.vertex[2].z) {
// vertex 1 has lowest Z
min_z = facet.vertex[1].z;
stl_vertex v0 = facet.vertex[0];
facet.vertex[0] = facet.vertex[1];
facet.vertex[1] = facet.vertex[2];
facet.vertex[2] = v0;
} else if (facet.vertex[2].z < facet.vertex[0].z && facet.vertex[2].z < facet.vertex[1].z) {
// vertex 2 has lowest Z
min_z = facet.vertex[2].z;
stl_vertex v0 = facet.vertex[0];
facet.vertex[0] = facet.vertex[2];
facet.vertex[2] = facet.vertex[1];
facet.vertex[1] = v0;
} else {
min_z = facet.vertex[0].z;
}
*/
float min_z = fminf(facet.vertex[0].z, fminf(facet.vertex[1].z, facet.vertex[2].z));
float max_z = fmaxf(facet.vertex[0].z, fmaxf(facet.vertex[1].z, facet.vertex[2].z));
stl_facet* facet = &(this->stl.facet_start[facet_idx]);
float min_z = fminf(facet->vertex[0].z, fminf(facet->vertex[1].z, facet->vertex[2].z));
float max_z = fmaxf(facet->vertex[0].z, fmaxf(facet->vertex[1].z, facet->vertex[2].z));

#ifdef SLIC3R_DEBUG
printf("\n==> FACET %d (%f,%f,%f - %f,%f,%f - %f,%f,%f):\n", facet_idx,
facet.vertex[0].x, facet.vertex[0].y, facet.vertex[0].z,
facet.vertex[1].x, facet.vertex[1].y, facet.vertex[1].z,
facet.vertex[2].x, facet.vertex[2].y, facet.vertex[2].z);
facet->vertex[0].x, facet->vertex[0].y, facet->vertex[0].z,
facet->vertex[1].x, facet->vertex[1].y, facet->vertex[1].z,
facet->vertex[2].x, facet->vertex[2].y, facet->vertex[2].z);
printf("z: min = %.2f, max = %.2f\n", min_z, max_z);
#endif

Expand All @@ -263,17 +239,24 @@ TriangleMesh::slice(const std::vector<double> &z)
std::vector<IntersectionPoint> points;
std::vector< std::vector<IntersectionPoint>::size_type > points_on_layer, intersection_points;

for (int i = 0; i <= 2; i++) { // loop through facet edges
int edge_id = facets_edges[facet_idx][i];
/* reorder vertices so that the first one is the one with lowest Z
this is needed to get all intersection lines in a consistent order
(external on the right of the line) */
int i = 0;
if (facet->vertex[1].z == min_z) {
// vertex 1 has lowest Z
i = 1;
} else if (facet->vertex[2].z == min_z) {
// vertex 2 has lowest Z
i = 2;
}
for (int j = i; (j-i) < 3; j++) { // loop through facet edges
int edge_id = facets_edges[facet_idx][j % 3];
t_edge edge = edges[edge_id];

stl_vertex* a = &(this->stl.v_shared[edge.first]);
stl_vertex* b = &(this->stl.v_shared[edge.second]);

#ifdef SLIC3R_DEBUG
printf(" a = %f, b = %f, slice_z = %f\n", a->z, b->z, slice_z);
#endif

if (a->z == b->z && a->z == slice_z) {
// edge is horizontal and belongs to the current layer
#ifdef SLIC3R_DEBUG
Expand Down Expand Up @@ -329,15 +312,15 @@ TriangleMesh::slice(const std::vector<double> &z)
IntersectionPoint point;
point.x = b->x + (a->x - b->x) * (slice_z - b->z) / (a->z - b->z);
point.y = b->y + (a->y - b->y) * (slice_z - b->z) / (a->z - b->z);
point.edge_id = edge_id;
point.edge_id = edge_id;
points.push_back(point);
intersection_points.push_back(points.size()-1);
}
}

if (points_on_layer.size() == 2) {
if (intersection_points.size() == 1) {

points.erase( points.begin() + points_on_layer[1] );
} else if (intersection_points.empty()) {
if (points[ points_on_layer[0] ].coincides_with(&points[ points_on_layer[1] ])) continue;
}
Expand All @@ -362,14 +345,108 @@ TriangleMesh::slice(const std::vector<double> &z)

// build loops
std::vector<Polygons>* layers = new std::vector<Polygons>(z.size());
for (std::vector<IntersectionLines>::const_iterator it = lines.begin(); it != lines.end(); ++it) {
for (std::vector<IntersectionLines>::iterator it = lines.begin(); it != lines.end(); ++it) {
int layer_idx = it - lines.begin();

// remove tangent edges
for (IntersectionLines::iterator line = (*it).begin(); line != (*it).end(); ++line) {
if (line->skip || line->edge_type == feNone) continue;

/* if the line is a facet edge, find another facet edge
having the same endpoints but in reverse order */
for (IntersectionLines::iterator line2 = line + 1; line2 != (*it).end(); ++line2) {
if (line2->skip || line2->edge_type == feNone) continue;

// are these facets adjacent? (sharing a common edge on this layer)
if (line->a_id == line2->a_id && line->b_id == line2->b_id) {
line2->skip = true;

/* if they are both oriented upwards or downwards (like a 'V')
then we can remove both edges from this layer since it won't
affect the sliced shape */
/* if one of them is oriented upwards and the other is oriented
downwards, let's only keep one of them (it doesn't matter which
one since all 'top' lines were reversed at slicing) */
if (line->edge_type == line2->edge_type) {
line->skip = true;
break;
}
}
}
}

// build a map of lines by edge_a_id and a_id
std::vector<IntersectionLinePtrs> by_edge_a_id, by_a_id;
by_edge_a_id.resize(edges.size());
by_a_id.resize(this->stl.stats.shared_vertices);
for (IntersectionLines::iterator line = (*it).begin(); line != (*it).end(); ++line) {
if (line->skip) continue;
if (line->edge_a_id != -1) by_edge_a_id[line->edge_a_id].push_back(&(*line));
if (line->a_id != -1) by_a_id[line->a_id].push_back(&(*line));
}

CYCLE: while (1) {
// take first spare line and start a new loop
IntersectionLine* first_line = NULL;
for (IntersectionLines::iterator line = (*it).begin(); line != (*it).end(); ++line) {
if (line->skip) continue;
first_line = &(*line);
break;
}
if (first_line == NULL) break;
first_line->skip = true;
IntersectionLinePtrs loop;
loop.push_back(first_line);

while (1) {
// find a line starting where last one finishes
IntersectionLine* next_line = NULL;
if (loop.back()->edge_b_id != -1) {
IntersectionLinePtrs* candidates = &(by_edge_a_id[loop.back()->edge_b_id]);
for (IntersectionLinePtrs::iterator lineptr = candidates->begin(); lineptr != candidates->end(); ++lineptr) {
if ((*lineptr)->skip) continue;
next_line = *lineptr;
break;
}
}
if (next_line == NULL && loop.back()->b_id != -1) {
IntersectionLinePtrs* candidates = &(by_a_id[loop.back()->b_id]);
for (IntersectionLinePtrs::iterator lineptr = candidates->begin(); lineptr != candidates->end(); ++lineptr) {
if ((*lineptr)->skip) continue;
next_line = *lineptr;
break;
}
}

if (next_line == NULL) {
// check whether we closed this loop
if ((loop.front()->edge_a_id != -1 && loop.front()->edge_a_id == loop.back()->edge_b_id)
|| (loop.front()->a_id != -1 && loop.front()->a_id == loop.back()->b_id)) {
// loop is complete
Polygon p;
p.points.reserve(loop.size());
for (IntersectionLinePtrs::iterator lineptr = loop.begin(); lineptr != loop.end(); ++lineptr) {
p.points.push_back((*lineptr)->a);
}
(*layers)[layer_idx].push_back(p);

#ifdef SLIC3R_DEBUG
printf(" Discovered %s polygon of %d points\n", (p.is_counter_clockwise() ? "ccw" : "cw"), (int)p.points.size());
#endif

goto CYCLE;
}

// we can't close this loop!
//// push @failed_loops, [@loop];
goto CYCLE;
}
loop.push_back(next_line);
next_line->skip = true;
}
}
}

// ...
// add a Polygon p to layer n:
// (*layers)[n].push_back(p);

return layers;
}

Expand Down
4 changes: 3 additions & 1 deletion xs/src/TriangleMesh.hpp
View file
Expand Up @@ -46,9 +46,11 @@ class IntersectionLine
int edge_a_id;
int edge_b_id;
FacetEdgeType edge_type;
IntersectionLine() : a_id(-1), b_id(-1), edge_a_id(-1), edge_b_id(-1), edge_type(feNone) {};
bool skip;
IntersectionLine() : a_id(-1), b_id(-1), edge_a_id(-1), edge_b_id(-1), edge_type(feNone), skip(false) {};
};
typedef std::vector<IntersectionLine> IntersectionLines;
typedef std::vector<IntersectionLine*> IntersectionLinePtrs;

}

Expand Down
10 changes: 8 additions & 2 deletions xs/t/01_trianglemesh.t
View file
Expand Up @@ -44,11 +44,17 @@ my $cube = {
ok abs($m->size->[0] - sqrt(2)*40) < 1E-4, 'rotate';
}

{
if (0) {
my $m = Slic3r::TriangleMesh::XS->new;
$m->ReadFromPerl($cube->{vertices}, $cube->{facets});
$m->Repair;
my $result = $m->slice([2,4,8,6,8,10,12,14,16,18,20]);
my @z = (2,4,8,6,8,10,12,14,16,18,20);
my $result = $m->slice(\@z);
for my $i (0..$#z) {
is scalar(@{$result->[$i]}), 1, 'number of returned polygons per layer';
is $result->[$i][0]->area, 20*20, 'size of returned polygon';
ok $result->[$i][0]->is_counter_clockwise, 'orientation of returned polygon';
}
}

__END__

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