ObjMesh.h

#pragma once

#include "TriangleMesh.h"
#include "AABB.h"

#include <vector>
#include <glm/glm.hpp>
#include <string>
#include <memory>

class ObjMesh : public TriangleMesh {
private:
    bool drawAdj;

public:
    static std::unique_ptr<ObjMesh> load(QOpenGLShaderProgram* prog, const char * fileName, bool center = false, bool genTangents = false);
    static std::unique_ptr<ObjMesh> loadWithAdjacency(QOpenGLShaderProgram* prog, const char * fileName, bool center = false);

    void render() override;

protected:
    ObjMesh(QOpenGLShaderProgram* prog);

    Aabb bbox;

    // Helper classes used for loading
    class GlMeshData {
    public:
        std::vector <GLfloat> points;
        std::vector <GLfloat> normals;
        std::vector <GLfloat> texCoords;
        std::vector <GLuint> faces;
        std::vector <GLfloat> tangents;

        void clear() {
            points.clear();
            normals.clear();
            texCoords.clear();
            faces.clear();
            tangents.clear();
        }
        void center(Aabb & bbox);
        void convertFacesToAdjancencyFormat();
    };

    class ObjMeshData {
    public:
        class ObjVertex {
        public:
            int pIdx;
            int nIdx;
            int tcIdx;

            ObjVertex() {
                pIdx = -1;
                nIdx = -1;
                tcIdx = -1;
            }

            ObjVertex(std::string &vertString);
            std::string str() {
                return std::to_string(pIdx) + "/" + std::to_string(tcIdx) + "/" + std::to_string(nIdx);
            }
        };

        std::vector <glm::vec3> points;
        std::vector <glm::vec3> normals;
        std::vector <glm::vec2> texCoords;
        std::vector <ObjVertex> faces;
        std::vector <glm::vec4> tangents;

        ObjMeshData() { }

        void generateNormalsIfNeeded();
        void generateTangents();
        void load( const char * fileName, Aabb & bbox );
        void toGlMesh(GlMeshData & data);
    };
};