#include "WorldObject.hpp"


template<class D>
inline WorldObjectAbstract<D>::~WorldObjectAbstract() {}

template<class D>
void WorldObjectAbstract<D>::LoadMeshFromObjFile(std::string file) {
    tinyobj::ObjReader reader;
    tinyobj::ObjReaderConfig reader_config;
    reader_config.mtl_search_path = "./";
    reader_config.triangulate = false;
    reader_config.vertex_color = false;

    if (!reader.ParseFromFile(file, reader_config))
        throw new std::runtime_error("Obj loader failure");

    const tinyobj::attrib_t& attrib = reader.GetAttrib();
    const std::vector<tinyobj::shape_t>& shapes = reader.GetShapes();

    try {
        mMesh.vertices.reserve(attrib.vertices.size());
    } catch (const std::length_error& ex) {
        throw ex;
    }

    // Reinterprete vertices to our format
    for (size_t i = 0; i < attrib.vertices.size(); i += 3)
        mMesh.vertices.push_back(Vertex(attrib.vertices[i], attrib.vertices[i+1], attrib.vertices[i+2]));

    // Loop over shapes/subparts
    for (size_t s = 0; s < shapes.size(); s++) {
        MeshPart subpart;

        // Loop over faces(polygon)
        size_t index_offset = 0;
        for (size_t f = 0; f < shapes[s].mesh.num_face_vertices.size(); f++) {
            size_t fv = size_t(shapes[s].mesh.num_face_vertices[f]);

            try {
                subpart.indices.reserve(shapes[s].mesh.indices.size());
            } catch (const std::length_error& ex) {
                throw ex;
            }

            // Loop over indices in the face.
            for (size_t v = 0; v < fv; v++) {
                subpart.indices.push_back(shapes[s].mesh.indices[index_offset + v].vertex_index);
                // Check if `normal_index` is zero or positive. negative = no normal data
                //if (idx.normal_index >= 0) {}

                // Check if `texcoord_index` is zero or positive. negative = no texcoord data
                //if (idx.texcoord_index >= 0) {}
            }

            index_offset += fv;

            // per-face material
            //shapes[s].mesh.material_ids[f];
        }

        mMesh.parts.push_back(subpart);
    }
}