STL2Voxel/STLReader.hpp

#pragma once
#include "Geometry.hpp"
#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <string>
#include <unordered_map>

bool readSTL(const std::string& filename, Mesh& mesh) {
    std::ifstream file(filename);
    if (!file.is_open()) {
        std::cerr << "Failed to open file: " << filename << std::endl;
        return false;
    }

    std::string line;
    std::unordered_map<Vec3<float>, unsigned int> vertexMap; // 用于去重
    unsigned int vertexIndex = 0;

    while (std::getline(file, line)) {
        std::istringstream stream(line);
        std::string keyword;

        if (line.find("facet normal") != std::string::npos) {
            std::getline(file, line); // Read the outer loop

            Vec3<float> vertices[3];
            for (int i = 0; i < 3; ++i) {
                std::getline(file, line);
                stream.clear();
                stream.str(line);
                stream >> keyword >> vertices[i].x >> vertices[i].y >> vertices[i].z;

                // 检查是否已存在该顶点
                if (vertexMap.find(vertices[i]) == vertexMap.end()) {
                    vertexMap[vertices[i]] = vertexIndex;
                    mesh.vertices.push_back(vertices[i]);
                    vertexIndex++;
                }
            }

            // 添加面索引
            mesh.faces.emplace_back(vertexMap[vertices[0]], vertexMap[vertices[1]], vertexMap[vertices[2]]);

            std::getline(file, line); // Read endloop
            std::getline(file, line); // Read endfacet
        }
    }

    file.close();
    return true;
}

//int main() {
//    Mesh mesh;
//    if (readSTL("../plate.stl", mesh)) {
//        std::cout << "Successfully read STL file." << std::endl;
//        std::cout << "Vertices count: " << mesh.vertices.size() << std::endl;
//        std::cout << "Faces count: " << mesh.faces.size() << std::endl;
//    } else {
//        std::cerr << "Failed to read STL file." << std::endl;
//    }
//    return 0;
//}