osci-render/Source/obj/WorldObject.cpp

#include "WorldObject.h"
#include "../chinese_postman/ChinesePostman.h"
#include "tiny_obj_loader.h"

struct pair_hash {
    inline std::size_t operator()(const std::pair<int, int>& v) const {
        return v.first * 31 + v.second;
    }
};

WorldObject::WorldObject(juce::InputStream& stream) {
    tinyobj::ObjReaderConfig reader_config;
    tinyobj::ObjReader reader;

    reader.ParseFromString(stream.readEntireStreamAsString().toStdString(), "", reader_config);

    vs = reader.GetAttrib().vertices;
	numVertices = vs.size() / 3;
    std::vector<tinyobj::shape_t> shapes = reader.GetShapes();
    
    std::unordered_set<std::pair<int, int>, pair_hash> edge_set;
	for (auto& shape : shapes) {
        int i = 0;
        int face = 0;
        while (i < shape.mesh.indices.size()) {
            int prevVertex = -1;
			for (int j = 0; j < shape.mesh.num_face_vertices[face]; j++) {
				int vertex = shape.mesh.indices[i].vertex_index;
				if (prevVertex != -1) {
					edge_set.insert(std::make_pair(prevVertex, vertex));
				}
				prevVertex = vertex;
				i++;
			}
            face++;
        }
	}

    std::list<std::pair<int, int>> edge_list;

    for (auto& edge : edge_set) {
        edge_list.push_back(edge);
    }

    Graph graph(numVertices, edge_list);
    pair<list<int>, double> solution = ChinesePostman(graph);
    list<int>& path = solution.first;

    double x = 0.0, y = 0.0, z = 0.0;
    double max = 0.0;

    for (int i = 0; i < numVertices; i++) {
		x += vs[i * 3];
		y += vs[i * 3 + 1];
		z += vs[i * 3 + 2];
		if (std::abs(vs[i * 3]) > max) {
			max = std::abs(vs[i * 3]);
		}
		if (std::abs(vs[i * 3 + 1]) > max) {
			max = std::abs(vs[i * 3 + 1]);
		}
		if (std::abs(vs[i * 3 + 2]) > max) {
			max = std::abs(vs[i * 3 + 2]);
		}
    }
    x /= numVertices;
    y /= numVertices;
    z /= numVertices;

    for (int i = 0; i < numVertices; i++) {
        vs[i * 3] = (vs[i * 3] - x) / max;
        vs[i * 3 + 1] = (vs[i * 3 + 1] - y) / max;
        vs[i * 3 + 2] = (vs[i * 3 + 2] - z) / max;
    }

    int prevVertex = -1;
    for (auto& vertex : path) {
        if (prevVertex != -1) {
            double x1 = vs[prevVertex * 3];
            double y1 = vs[prevVertex * 3 + 1];
            double z1 = vs[prevVertex * 3 + 2];
            double x2 = vs[vertex * 3];
            double y2 = vs[vertex * 3 + 1];
            double z2 = vs[vertex * 3 + 2];

            edges.push_back(Line3D(x1, y1, z1, x2, y2, z2));
        }
        prevVertex = vertex;
    }
}