自作ポリゴンデータフォーマットを考えた

import bpy
import sys


def my_triangulation(target = bpy.context.object) :

    # なにも選択されていなければ終了
    if target == None:
        return False

    # メッシュだけを対象とする
    if target.type == 'MESH' :

        # EDITモードへ移行するために現在のモードを保存して奥
        current = bpy.context.object.mode

        # Editモードへ移行
        bpy.ops.object.mode_set(mode = 'EDIT')

        # 三角形分割実行
        bpy.ops.mesh.quads_convert_to_tris()

        # モードをリストア。これをしないとEDITモードのままで終わる。
        bpy.ops.object.mode_set(mode = current)

    else:
        return False

    return True



############################################
############################################

def to_simple_polygon_file(outputto) :
    obj = bpy.context.active_object

    mesh = obj.data

    pvecname = "points"   # 頂点データの配列の変数名
    vnvecname = "vnorms"  # 頂点法線の配列の変数名
    fvecname = "faces"    # 面データの配列の変数名
    fnvecname = "fnorms"  # 面法線の配列の変数名

    print("/////////////////////////////////////")

    print("#szlm,-,-,-,-", file = outputto)


    for f in mesh.polygons:
        if not fvecname is None :
            print(
                "ti,",
                f.vertices[0], ",",
                f.vertices[1], ",",
                f.vertices[2],
                0,
                file = outputto
            )

        if not fnvecname is None :
            print(
                "tn,",
                f.normal.x, ",",
                f.normal.y, ",",
                f.normal.z,
                0,
                file = outputto
            )

    for v in mesh.vertices:
        if not pvecname is None :
            print(
                "pp,",
                v.co.x, ",",
                v.co.y, ",",
                v.co.z,
                0,
                file = outputto
            )

        if not vnvecname is None :
            print(
                "pn,",
                v.normal.x, ",",
                v.normal.y, ",",
                v.normal.z,
                0,
                file = outputto
            )



# 三角形分割
ret = my_triangulation()

o = open('c:/data/myfile3.txt', 'w')
to_simple_polygon_file(o)
o.close()
#as_cpp_array(sys.stdout)

#pragma once

#pragma warning(disable:4996)

#include <vector>
#include <array>
#include <type_traits>
#include <string>

/*
#szlm,-,-,-,-
ti,1,2,3,-
tc,0.1,0.1,0.1,-
tn,0.1,0.1,0.1,-
pp,0.1,0.1,0.1,-
pc,0.1,0.1,0.1,-
pn,0.1,0.1,0.1,-
*/

struct szlm {
  std::vector<std::array<int, 4>> ti;
  std::vector<std::array<float, 4>> 
    tc // triangle color
    ,tn// triangle normal
    ,pp// point position
    ,pc// point color
    ,pn// point normal
    ;
};
//! @brief 簡易的メッシュフォーマットの読み込み
//! @param [in] file ファイル名
//! @param [out] mesh メッシュを保存する構造体
bool read_mesh(const char* file, szlm* mesh) {
  FILE* fp = fopen(file, "r");
  if (fp == NULL)
    return false;

  constexpr size_t DIM = 4;

  const size_t BUFFERSIZE = 2048;
  char b[BUFFERSIZE];
  //,で分割
  auto split = [](char* buffer, std::vector<std::string>& split)->void {
    const char* sp = ",";
    char* tok = strtok(buffer, sp);
    while (tok != NULL) {
      split.push_back(tok);
      tok = strtok(NULL, sp);  /* 2回目以降 */
    }
  };
  //配列へ入力

  while (fgets(b, BUFFERSIZE, fp) != NULL) {
    std::array<int, DIM> ii;
    std::array<float, DIM> ff;
    std::fill_n(ii.begin(), DIM, -1);
    std::fill_n(ff.begin(), DIM, INFINITY);
    std::vector<std::string> line;
    split(b, line);//入力行を,で分割
    for (size_t i = 1; i < (std::min)(DIM, line.size()); i++) {
      ii[i - 1] = atoi(line[i].c_str());
      ff[i - 1] = atof(line[i].c_str());
    }

    if (b[0] == '#')continue;
    else if (strncmp(b, "ti", 2) == 0)mesh->ti.push_back({ ii[0],ii[1],ii[2],ii[3] });// triangle pointindex
    else if (strncmp(b, "tc", 2) == 0)mesh->tc.push_back({ ff[0],ff[1],ff[2],ff[3] });// triangle color
    else if (strncmp(b, "tn", 2) == 0)mesh->tn.push_back({ ff[0],ff[1],ff[2],ff[3] });// triangle normal
    else if (strncmp(b, "pp", 2) == 0)mesh->pp.push_back({ ff[0],ff[1],ff[2],ff[3] });// point position
    else if (strncmp(b, "pc", 2) == 0)mesh->pc.push_back({ ff[0],ff[1],ff[2],ff[3] });// point color
    else if (strncmp(b, "pn", 2) == 0)mesh->pn.push_back({ ff[0],ff[1],ff[2],ff[3] });// point normal
  }
  fclose(fp);

  return false;
}

void disp(const szlm& mesh) {

    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    glBegin(GL_TRIANGLES);
    for (size_t i = 0; i < mesh.ti.size(); i++) {
        int v0 = mesh.ti[i][0];
        int v1 = mesh.ti[i][1];
        int v2 = mesh.ti[i][2];

        glNormal3fv(mesh.tn[i].data());
        glVertex3fv(mesh.pp[v0].data());
        glVertex3fv(mesh.pp[v1].data());
        glVertex3fv(mesh.pp[v2].data());

    }
    glEnd();

}


int main()
{

    struct szlm mesh;
    read_mesh("C:\\data\\myfile3.txt", &mesh);

    /* ... */


    disp(mesh);
}