// Reads a list of points and returns a list of segments corresponding to
// the weighted Alpha Shape.
int main()
{
std::list<Point> points;
file_input(points);
std::vector<Gt::Segment_2> segments;
alpha_edges(points.begin(), points.end(),
FT(10000),Alpha_shape_2::GENERAL,
std::back_inserter(segments));
std::cout << segments.size() << " alpha shape edges." << std::endl;
return 0;
}
// Reads a list of points and returns a list of segments
// corresponding to the Alpha shape.
int main()
{
std::list<Point> points;
if(! file_input(std::back_inserter(points))){
return -1;
}
Alpha_shape_2 A(points.begin(), points.end(),
FT(10000),
Alpha_shape_2::GENERAL);
std::vector<Segment> segments;
alpha_edges( A, std::back_inserter(segments));
std::cout << "Alpha Shape computed" << std::endl;
std::cout << segments.size() << " alpha shape edges" << std::endl;
std::cout << "Optimal alpha: " << *A.find_optimal_alpha(1)<<std::endl;
return 0;
}
int alpha_shape(vertex_t *vertices, size_t count, double alpha,
vertex_t **res, size_t *res_count, char **err_msg)
{
try {
std::list<Point> points;
{
std::vector<Point> pv;
for (std::size_t j = 0; j < count; ++j) {
Point p(vertices[j].x, vertices[j].y);
pv.push_back(p);
}
std::sort(pv.begin(), pv.end(),
[](const Point &e1, const Point &e2)->bool {
return e2.y() < e1.y();
});
std::stable_sort(pv.begin(), pv.end(),
[](const Point &e1, const Point &e2)->bool {
return e2.x() < e1.x();
});
pv.erase(std::unique(pv.begin(), pv.end()), pv.end());
if (pv.size() != count && pv.size() < 3) {
*err_msg = strdup("After eliminating duplicated points, less than 3 points remain!!. Alpha shape calculation needs at least 3 vertices.");
return -1;
}
points.insert(points.begin(), pv.begin(), pv.end());
}
Alpha_shape_2 A(points.begin(), points.end(),
coord_type(10000),
Alpha_shape_2::REGULARIZED);
std::vector<Segment> segments;
// std::vector<Segment> result;
// Alpha_shape_2::Alpha_shape_vertices_iterator vit;
// Alpha_shape_2::Vertex_handle vertex;
// Alpha_shape_2::Alpha_shape_edges_iterator eit;
// Alpha_shape_2::Edge edge;
// Alpha_shape_2::Face_iterator fit;
// Alpha_shape_2::Face_handle face;
if (alpha <= 0.0)
{
alpha = *A.find_optimal_alpha(1);
}
A.set_alpha(alpha);
alpha_edges( A, std::back_inserter(segments));
// Segment s = segments.at(0);
// find_next_edge(s, segments, result);
if (segments.empty())
{
*res = NULL;
*res_count = 0;
}
else
{
std::set<int> unusedIndexes;
for (unsigned int i = 0; i < segments.size(); i++)
{
unusedIndexes.insert(i);
}
std::vector<Polygon_2> rings;
Polygon_2 ring;
ring.push_back(segments.at(0).source());
rings.push_back(ring);
unusedIndexes.erase(0);
find_next_edge(segments.at(0), segments, unusedIndexes, rings);
size_t result_count = 0;
for (unsigned int i = 0; i < rings.size(); i++)
{
Polygon_2 ring = rings.at(i);
result_count += ring.size();
}
result_count += rings.size() - 1;
*res = (vertex_t *) malloc(sizeof(vertex_t) * result_count);
*res_count = result_count;
int idx = 0;
for (unsigned int i = 0; i < rings.size(); i++)
{
if (i > 0)
{
(*res)[idx].x = DBL_MAX;
(*res)[idx].y = DBL_MAX;
idx++;
}
Polygon_2 ring = rings.at(i);
for(unsigned int j = 0; j < ring.size(); j++)
{
Point point = ring.vertex(j);
(*res)[idx].x = point.x();
(*res)[idx].y = point.y();
idx++;
}
}
}
*err_msg = NULL;
return EXIT_SUCCESS;
} catch ( ... ) {
*err_msg = strdup("Caught unknown expection!");
}
return -1;
}
int main(int argc, char* argv[])
{
//check points flag
bool bpoints = false;
bool bsegments = false;
bool optalpha = false;
char* filename;
float alpha = -1;
for(int i =0; i < argc; i++) {
if (strcmp(argv[i],"-p")==0) {
bpoints = true;
}
else if (strcmp(argv[i],"-s")==0) {
bsegments = true;
}
if (strcmp(argv[i],"-a") == 0) {
alpha = atof(argv[i+1]);
}
if (strcmp(argv[i],"--optimalalpha") == 0) {
optalpha = true;
}
if (strcmp(argv[i],"-i") == 0) {
filename = argv[i+1];
}
if (strcmp(argv[i],"-h") == 0) {
print_help();
return 0;
}
}
//File Input
std::list<Point> points;
if(! file_input(std::back_inserter(points),filename)) {
return -1;
}
//Alpha shape compute
Alpha_shape_2 A(points.begin(), points.end());
A.set_mode(Alpha_shape_2::GENERAL);
Alpha_iterator opt = A.find_optimal_alpha(1);
if (alpha != -1) {
A.set_alpha(alpha);
}
else {
A.set_alpha(*opt);
}
std::vector<Segment> segments;
std::vector<Vertex_handle> vertices;
std::vector< Polygon_2 > polygons;
alpha_edges( A, std::back_inserter(segments));
alpha_vertices( A, std::back_inserter(vertices));
segments_to_polygons(segments, polygons);
//Fill and print result
if (optalpha) {
std::cout << *opt << std::endl;
return 0;
}
if (bpoints) {
toWKT_vertices(vertices);
}
else if (bsegments) {
toWKT_segments(segments);
}
else {
toWKT_polygons(polygons);
}
return 0;
}
