Introducing connected components

[jeanchristopheruel]

Introducing connected components

Regarding #21, this PR addresses the need to be able to differentiate between different solid (unconnected components) in a mesh.

This PR introduces:

• In python: openstl.topology.find_connected_components
• In C++: openstl::findConnectedComponents

Python Usage Example:

import openstl

# Define vertices and faces for two disconnected components
vertices = [
 [0.0, 0.0, 0.0],
 [1.0, 0.0, 0.0],
 [0.0, 1.0, 0.0],
 [2.0, 2.0, 0.0],
 [3.0, 2.0, 0.0],
 [2.5, 3.0, 0.0],
]

faces = [
 [0, 1, 2],  # Component 1
 [3, 4, 5],  # Component 2
]

# Identify connected components of faces
connected_components = openstl.topology.find_connected_components(vertices, faces)

# Print the result
print(f"Number of connected components: {len(connected_components)}")
for i, component in enumerate(connected_components):
 print(f"Component {i + 1}: {component}")

C++ Usage Example

#include <stl.h>
#include <vector>
#include <iostream>

using namespace openstl;

int main() {
    std::vector<Vec3> vertices = {
        {0.0f, 0.0f, 0.0f}, {1.0f, 0.0f, 0.0f}, {0.0f, 1.0f, 0.0f},  // Component 1
        {2.0f, 2.0f, 0.0f}, {3.0f, 2.0f, 0.0f}, {2.5f, 3.0f, 0.0f}   // Component 2
    };

    std::vector<Face> faces = {
        {0, 1, 2},  // Component 1
        {3, 4, 5},  // Component 2
    };

    const auto& connected_components = findConnectedComponents(vertices, faces);

    std::cout << "Number of connected components: " << connected_components.size() << "\\n";
    for (size_t i = 0; i < connected_components.size(); ++i) {
        std::cout << "Component " << i + 1 << ":\\n";
        for (const auto& face : connected_components[i]) {
            std::cout << "  {" << face[0] << ", " << face[1] << ", " << face[2] << "}\\n";
        }
    }

    return 0;
}