bool Graph_Completer::crosses_an_edge(const segment &S)
{
bool crossing = false;
segment segment_1 = S, segment_2;
vertex_label label;
Point content;
std::vector<vertex_label> N;
unsigned int j, k;
for(j=0; j<G_->nb_vertices(); j++)
{
label = G_->get_label_by_index(j);
content = G_->get_content_by_index(j);
N = G_->get_neighbors_by_index(j);
for(k=0; k<N.size(); k++)
{
if(N[k] < label)
{
continue;
}
else
{
segment_2 = segment(content, G_->get_content_by_label(N[k]));
if (segment_1.first.get_affix() == segment_2.first.get_affix() &&
segment_1.second.get_affix() == segment_2.second.get_affix())
{
crossing = true;
break;
}
if(segment_1.first.get_affix() == segment_2.first.get_affix() ||
segment_1.first.get_affix() == segment_2.second.get_affix() ||
segment_1.second.get_affix() == segment_2.first.get_affix() ||
segment_1.second.get_affix() == segment_2.second.get_affix())
{
continue;
}
if(are_intersecting(segment_1,segment_2))
{
crossing = true;
break;
}
}
}
if(crossing)
{
break;
}
}
return crossing;
}
void c15()
{
double lines[max_number_of_lines][parameters + 2]; // array to store lines, entered by user
int lines_entered = 0; // counter, how many lines are entered
const int checked = 1; // flag line is already processed (used in parallelness check and printing)
const int not_checked = -1; // flag line is not yet processed
// getting lines from user
for (int line = 0; line < max_number_of_lines; line++, lines_entered++)
{
double* input_line = get_line();
if (is_stop(input_line))
{
lines_entered--;
break;
}
else
{
lines[line][a] = input_line[a];
lines[line][b] = input_line[b];
lines[line][c] = input_line[c];
lines[line][state] = not_checked;
lines[line][parallelness] = not_checked;
}
}
bool exists_parallels = false;
// mark lines parallel
for (int line = 0; line < lines_entered; line++)
{
// if line not yet marked as being parallel
if (lines[line][state] == not_checked)
{
// loop through lines, starting from next one till end
for (int next_line = line + 1; next_line < lines_entered; next_line++)
{
if (is_parallel(lines[line], lines[next_line]))
{
// mark current line as parallel to line from outer loop
lines[next_line][state] = checked;
lines[next_line][parallelness] = line;
exists_parallels = true;
}
}
}
}
// reseting state for printing
for (int line = 0; line < lines_entered; line++)
lines[line][state] = not_checked;
// print out result of parallelness check
if (exists_parallels)
{
bool has_parallels;
print("Parallel lines are:");
for (int line = 0; line < lines_entered; line++)
{
// cout << "entering with line " << line + 1 << endl;
string output_lines = " Line " + to_char(line+1);
has_parallels = false;
// if line is not yet printed
if (lines[line][state] == not_checked)
{
for (int next_line = line + 1; next_line < lines_entered; next_line++)
{
if (lines[next_line][parallelness] == line)
{
lines[next_line][state] = checked;
output_lines += ", line " + to_char(next_line+1);
has_parallels = true;
}
}
}
if (has_parallels) print(output_lines);
}
}
else
{
print("There are no parallel lines.");
}
// combinations by 3 lines out of all lines
bool exists_triple_intersection = false;
for (int line1 = 0; line1 < lines_entered; line1++)
{
for (int line2 = line1+1; line2 < lines_entered; line2++)
{
for (int line3 = line2+1; line3 < lines_entered; line3++)
{
if (are_intersecting(lines[line1], lines[line2], lines[line3]))
{
exists_triple_intersection = true;
// double* intersection_of_1_and_2 = intersection(lines[line1], lines[line2]);
// cout << "Intersection is " << intersection_of_1_and_2[0] << ";" << intersection_of_1_and_2[1];
cout << endl << "Following lines are intersecting at same point: ";
print(lines[line1]);
print(lines[line2]);
print(lines[line3]);
}
}
}
}
if (!exists_triple_intersection)
print("Not triple intersection exists.");
}
