BD1 to OBJ Converter (Licence: CC0)

Main.cpp

#include <string>
#include <iostream>
#include <vector>
#include <Windows.h>

#include "MapData.hpp"

void printBd1Structure(MapData map)
{
    printf("- Textures\n");
    for (int i = 0; i < NUM_TEXTURES; i++) {
        printf("    - %d: %s\n", i, map.texturesPath[i].c_str());
    }

    printf("\n- Num of blocks: %d\n", map.numBlocks);

    for (int i = 0; i < map.numBlocks; i++) {
        printf("\n- Block %d\n", i);

        for (int j = 0; j < NUM_VERTICES; j++) {
            printf("    - Vertex %d (X: %f Y: %f Z: %f)\n",
                j,
                map.block[i].vertex[j].x,
                map.block[i].vertex[j].y,
                map.block[i].vertex[j].z);
        }

        for (int j = 0; j < NUM_FACES; j++) {
            printf("    - Face %d\n", j);
            printf("        - Texture: %d\n", map.block[i].face[j].textureId);

            for (int k = 0; k < 4; k++) {
                printf("        - UV %d (U: %f V: %f)\n", k, map.block[i].face[j].uv[k].u, map.block[i].face[j].uv[k].v);
            }
        }
    }
}

void outputFaceLine(MapData &map, FILE *fp, int textureId, int v1, int vt1, int v2, int vt2, int v3, int vt3, int v4, int vt4)
{
    static int lastTexture = -1;

    if (lastTexture != textureId) {
        fprintf(fp, "usemtl %s\n", map.texturesPath[textureId].c_str());
        lastTexture = textureId;
    }
    fprintf(fp, "f %d/%d %d/%d %d/%d %d/%d\n", v1, vt1, v2, vt2, v3, vt3, v4, vt4);
};

void exportObjFile(MapData map, std::wstring path)
{
    FILE *fp;
    fp = _wfopen(path.c_str(), L"wb");

    fprintf(fp, "# generated by bd1Parser\n\n");
    fprintf(fp, "mtllib temp.mtl\n\n");

    for (int i = 0; i < map.numBlocks; i++) {
        for (int j = 0; j < NUM_VERTICES; j++) {
            fprintf(fp, "v %f %f %f\n", -map.block[i].vertex[j].x / 100, map.block[i].vertex[j].y / 100, map.block[i].vertex[j].z / 100);
        }
    }

    fprintf(fp, "\n\n");

    for (int i = 0; i < map.numBlocks; i++) {
        for (int j = 0; j < NUM_FACES; j++) {
            for (int k = 0; k < 4; k++) {
                fprintf(fp, "vt %f %f\n", map.block[i].face[j].uv[k].u, 1 - map.block[i].face[j].uv[k].v);
            }
        }
    }

    fprintf(fp, "\n\n");

    for (int i = 0; i < map.numBlocks; i++) {
        int b = i * 8;
        int uvb = i * 24;

        outputFaceLine(map, fp, map.block[i].face[0].textureId, b + 1, uvb + 4, b + 2, uvb + 3, b + 3, uvb + 2, b + 4, uvb + 1); // 上
        outputFaceLine(map, fp, map.block[i].face[1].textureId, b + 8, uvb + 8, b + 7, uvb + 7, b + 6, uvb + 6, b + 5, uvb + 5); // 下
        outputFaceLine(map, fp, map.block[i].face[2].textureId, b + 5, uvb + 12, b + 6, uvb + 11, b + 2, uvb + 10, b + 1, uvb + 9); // 前
        outputFaceLine(map, fp, map.block[i].face[3].textureId, b + 6, uvb + 16, b + 7, uvb + 15, b + 3, uvb + 14, b + 2, uvb + 13); // 右
        outputFaceLine(map, fp, map.block[i].face[4].textureId, b + 7, uvb + 20, b + 8, uvb + 19, b + 4, uvb + 18, b + 3, uvb + 17); // 後
        outputFaceLine(map, fp, map.block[i].face[5].textureId, b + 8, uvb + 24, b + 5, uvb + 23, b + 1, uvb + 22, b + 4, uvb + 21); // 左
    }

    fclose(fp);
}

void exportMtlFile(MapData map, std::wstring path)
{
    FILE *fp;
    fp = _wfopen(path.c_str(), L"wb");

    fprintf(fp, "# generated by bd1Parser\n");

    for (int i = 0; i < 10; i++) {
        if (map.texturesPath[i].empty()) {
            continue;
        }

        fprintf(fp, "\nnewmtl %s\n", map.texturesPath[i].c_str());
        fprintf(fp, "Ka 0.40000 0.40000 0.40000\n");
        fprintf(fp, "Kd 0.90000 0.90000 0.90000\n");
        fprintf(fp, "Ks 0.00000 0.00000 0.00000\n");
        fprintf(fp, "Ns 5.00000\n");
        fprintf(fp, "map_Kd %s\n", map.texturesPath[i].c_str());
    }

    fclose(fp);
}

int openBd1FileDialog(std::wstring &path) {
    OPENFILENAME ofn = {};
    wchar_t _path[1024] = {};
    ofn.lStructSize = sizeof(OPENFILENAME);
    ofn.lpstrFilter = L"Block data(*.bd1)\0*.bd1\0";
    ofn.lpstrFile = _path;
    ofn.nMaxFile = sizeof(_path);
    ofn.lpstrTitle = L"Select a block data file";
    ofn.Flags = OFN_FILEMUSTEXIST;

    if (!GetOpenFileName(&ofn)) {
        return 1;
    }

    path = _path;

    return 0;
}

int parseBd1(std::wstring bd1Path, MapData &map) {

    FILE *fp;
    fp = _wfopen(bd1Path.c_str(), L"rb");

    if (!fp) {
        printf("bd1 open failed!\n");
        fclose(fp);
        return 1;
    }
    
    // textures
    for (int i = 0; i < NUM_TEXTURES; i++) {
        char texturePath[32];

        fread(texturePath, sizeof(texturePath) - 1, 1, fp);
        map.texturesPath[i] = texturePath;
    }

    // block count
    fread(&map.numBlocks, 1, 1, fp);
    // skip 1byte
    fseek(fp, 1, SEEK_CUR);
    
    for (int i = 0; i < map.numBlocks; i++) {

        float vertexRawData[3 * NUM_VERTICES];
        fread(vertexRawData, sizeof(float), (3 * NUM_VERTICES), fp);

        // vertex data
        for (int j = 0; j < NUM_VERTICES; j++) {
            map.block[i].vertex[j].x = vertexRawData[0 + j];
            map.block[i].vertex[j].y = vertexRawData[8 + j];
            map.block[i].vertex[j].z = vertexRawData[16 + j];
        }

        // uv data
        float uvRawData[48]; // 48 * 4 = 192 bytes
        fread(uvRawData, sizeof(float), 48, fp);

        for (int face = 0; face < NUM_FACES; face++) {
            for (int uvs = 0; uvs < 4; uvs++) {
                map.block[i].face[face].uv[uvs].u = uvRawData[face * 4 + uvs];
                map.block[i].face[face].uv[uvs].v = uvRawData[face * 4 + uvs + 24];
            }
        }

        // texture selection
        uint8_t texSelectRawData[24];
        fread(texSelectRawData, 1, 24, fp);

        for (int face = 0; face < NUM_FACES; face++) {
            map.block[i].face[face].textureId = texSelectRawData[face * 4];
        }

        // enable / disable flag
        fread(&map.block[i].isEnabled, 1, 1, fp);
        // skip 3 bytes
        fseek(fp, 3, SEEK_CUR);
    }

    fclose(fp);
    return 0;
}

int main()
{
    std::wstring bd1Path;
    if (openBd1FileDialog(bd1Path)) {
        return 1;
    }

    std::wstring objPath = bd1Path.substr(0, bd1Path.find_last_of('\\')) + L"\\temp.obj";
    std::wstring mtlPath = bd1Path.substr(0, bd1Path.find_last_of('\\')) + L"\\temp.mtl";

    MapData map;
    parseBd1(bd1Path, map);

    printBd1Structure(map);
    exportObjFile(map, objPath);
    exportMtlFile(map, mtlPath);

    return 0;
}

MapData.hpp

#pragma once

#include <iostream>
#include <vector>

const auto NUM_TEXTURES = 10;
const auto NUM_FACES = 6;
const auto NUM_VERTICES = 8;

struct MapData
{
    struct Block
    {
        struct Face
        {
            struct Uv
            {
                float u;
                float v;
            } uv[4];

            uint8_t textureId;

        } face[NUM_FACES];

        struct Vertices
        {
            float x;
            float y;
            float z;
        } vertex[NUM_VERTICES];

        bool isEnabled;
    } block[160];

    std::string texturesPath[NUM_TEXTURES];
    uint8_t numBlocks;
};