ObjLoader.h

#pragma once
#include <vector>
#include <string>
#include <fstream>
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <memory>

#include "TriangleMesh.h"
#include <glm/glm.hpp>

struct TriangleFaceIndex {
    int VertexID[3], NormalID[3], TexID[3];
    TriangleFaceIndex() {}
    TriangleFaceIndex(const std::vector<std::tuple<int, int, int>>& vs) {
        int i = 0;
        for (auto& [a, b, c] : vs) {
            VertexID[i] = a;
            TexID[i] = b;
            NormalID[i] = c;
            i++;
        }
    }
    TriangleFaceIndex(int a, int b, int c) {
        VertexID[0] = a;
        VertexID[1] = b;
        VertexID[2] = c;
    }
};



class ObjLoader {
public:

    void load(const std::string& path, FILE* prtFile);
    std::vector<glm::vec3> Positions;
    std::vector<glm::vec2> TexCoords;
    std::vector<glm::vec3> Normals;
    std::vector<glm::mat3> PRTs[3];
    std::vector<glm::mat3> PRTi[3];

    std::vector<glm::ivec3> Triangles;
    std::vector<VertexData> Vertices;

    std::shared_ptr<TriangleMesh> GetMesh(const glm::vec3& color, const glm::mat4& transform);
private:
    static constexpr int MAX_BUFFER = 100005;
    static char lineBuffer[MAX_BUFFER];
    int _ptr;
    int _totV;


    void process();
    char getNext() { return lineBuffer[++_ptr]; }
    char getCur() { return lineBuffer[_ptr]; }
    char getPrev() { return lineBuffer[--_ptr]; }
    void delSpace() {
        char c = lineBuffer[_ptr];
        while (c == ' ' || c == '\n' || c == '\t' || c == '\r') {
            c = getNext();
        }
    }
};