assimp/code/AssetLib/MMD/MMDImporter.cpp

/*
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Open Asset Import Library (assimp)
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Copyright (c) 2006-2022, assimp team

All rights reserved.

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  following disclaimer.

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  derived from this software without specific prior
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/

#ifndef ASSIMP_BUILD_NO_MMD_IMPORTER

#include "AssetLib/MMD/MMDImporter.h"
#include "AssetLib/MMD/MMDPmdParser.h"
#include "AssetLib/MMD/MMDPmxParser.h"
#include "AssetLib/MMD/MMDVmdParser.h"
#include "PostProcessing/ConvertToLHProcess.h"

#include <assimp/DefaultIOSystem.h>
#include <assimp/ai_assert.h>
#include <assimp/scene.h>
#include <assimp/Importer.hpp>


#include <iomanip>
#include <memory>
#include <sstream>

static const aiImporterDesc desc = { "MMD Importer",
    "",
    "",
    "surfaces supported?",
    aiImporterFlags_SupportTextFlavour,
    0,
    0,
    0,
    0,
    "pmx" };

namespace Assimp {

using namespace std;

// ------------------------------------------------------------------------------------------------
//  Default constructor
MMDImporter::MMDImporter() :
        m_Buffer(),
        m_strAbsPath() {
    DefaultIOSystem io;
    m_strAbsPath = io.getOsSeparator();
}

// ------------------------------------------------------------------------------------------------
//  Destructor.
MMDImporter::~MMDImporter() {
    // empty
}

// ------------------------------------------------------------------------------------------------
//  Returns true, if file is an pmx file.
bool MMDImporter::CanRead(const std::string &pFile, IOSystem *pIOHandler,
        bool /*checkSig*/) const {
    static const char *tokens[] = { "PMX " };
    return SearchFileHeaderForToken(pIOHandler, pFile, tokens, AI_COUNT_OF(tokens));
}

// ------------------------------------------------------------------------------------------------
const aiImporterDesc *MMDImporter::GetInfo() const {
    return &desc;
}

// ------------------------------------------------------------------------------------------------
//  MMD import implementation
void MMDImporter::InternReadFile(const std::string &file, aiScene *pScene,
        IOSystem* pIOHandler) {

    auto streamCloser = [&](IOStream *pStream) {
        pIOHandler->Close(pStream);
    };

    static const std::string mode = "rb";
    const std::unique_ptr<IOStream, decltype(streamCloser)> fileStream(pIOHandler->Open(file, mode), streamCloser);

    if (fileStream == nullptr) {
        throw DeadlyImportError("Failed to open file ", file, ".");
    }

    const size_t fileSize = fileStream->FileSize();
    if (fileSize < sizeof(pmx::PmxModel))
    {
        throw DeadlyImportError(file, " is too small.");
    }

    std::vector<char> contents(fileStream->FileSize());
    fileStream->Read(contents.data(), 1, contents.size());

    std::istringstream iss(std::string(contents.begin(), contents.end()));

    pmx::PmxModel model;
    model.Read(&iss);

    CreateDataFromImport(&model, pScene);
}

// ------------------------------------------------------------------------------------------------
void MMDImporter::CreateDataFromImport(const pmx::PmxModel *pModel,
        aiScene *pScene) {
    if (pModel == nullptr) {
        return;
    }

    aiNode *pNode = new aiNode;
    if (!pModel->model_name.empty()) {
        pNode->mName.Set(pModel->model_name);
    }

    pScene->mRootNode = pNode;

    pNode = new aiNode;
    pScene->mRootNode->addChildren(1, &pNode);
    pNode->mName.Set(string(pModel->model_name) + string("_mesh"));

    // split mesh by materials
    pNode->mNumMeshes = pModel->material_count;
    pNode->mMeshes = new unsigned int[pNode->mNumMeshes];
    for (unsigned int index = 0; index < pNode->mNumMeshes; index++) {
        pNode->mMeshes[index] = index;
    }

    pScene->mNumMeshes = pModel->material_count;
    pScene->mMeshes = new aiMesh *[pScene->mNumMeshes];
    for (unsigned int i = 0, indexStart = 0; i < pScene->mNumMeshes; i++) {
        const int indexCount = pModel->materials[i].index_count;

        pScene->mMeshes[i] = CreateMesh(pModel, indexStart, indexCount);
        pScene->mMeshes[i]->mName = pModel->materials[i].material_name;
        pScene->mMeshes[i]->mMaterialIndex = i;
        indexStart += indexCount;
    }

    // create node hierarchy for bone position
    std::unique_ptr<aiNode *[]> ppNode(new aiNode *[pModel->bone_count]);
    for (auto i = 0; i < pModel->bone_count; i++) {
        ppNode[i] = new aiNode(pModel->bones[i].bone_name);
    }

    for (auto i = 0; i < pModel->bone_count; i++) {
        const pmx::PmxBone &bone = pModel->bones[i];

        if (bone.parent_index < 0) {
            pScene->mRootNode->addChildren(1, ppNode.get() + i);
        } else {
            ppNode[bone.parent_index]->addChildren(1, ppNode.get() + i);

            aiVector3D v3 = aiVector3D(
                    bone.position[0] - pModel->bones[bone.parent_index].position[0],
                    bone.position[1] - pModel->bones[bone.parent_index].position[1],
                    bone.position[2] - pModel->bones[bone.parent_index].position[2]);
            aiMatrix4x4::Translation(v3, ppNode[i]->mTransformation);
        }
    }

    // create materials
    pScene->mNumMaterials = pModel->material_count;
    pScene->mMaterials = new aiMaterial *[pScene->mNumMaterials];
    for (unsigned int i = 0; i < pScene->mNumMaterials; i++) {
        pScene->mMaterials[i] = CreateMaterial(&pModel->materials[i], pModel);
    }

    // Convert everything to OpenGL space
    MakeLeftHandedProcess convertProcess;
    convertProcess.Execute(pScene);

    FlipUVsProcess uvFlipper;
    uvFlipper.Execute(pScene);

    FlipWindingOrderProcess windingFlipper;
    windingFlipper.Execute(pScene);
}

// ------------------------------------------------------------------------------------------------
aiMesh *MMDImporter::CreateMesh(const pmx::PmxModel *pModel,
        const int indexStart, const int indexCount) {
    aiMesh *pMesh = new aiMesh;

    pMesh->mNumVertices = indexCount;

    pMesh->mNumFaces = indexCount / 3;
    pMesh->mFaces = new aiFace[pMesh->mNumFaces];

    const int numIndices = 3; // triangular face
    for (unsigned int index = 0; index < pMesh->mNumFaces; index++) {
        pMesh->mFaces[index].mNumIndices = numIndices;
        unsigned int *indices = new unsigned int[numIndices];
        indices[0] = numIndices * index;
        indices[1] = numIndices * index + 1;
        indices[2] = numIndices * index + 2;
        pMesh->mFaces[index].mIndices = indices;
    }

    pMesh->mVertices = new aiVector3D[pMesh->mNumVertices];
    pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
    pMesh->mTextureCoords[0] = new aiVector3D[pMesh->mNumVertices];
    pMesh->mNumUVComponents[0] = 2;

    // additional UVs
    for (int i = 1; i <= pModel->setting.uv; i++) {
        pMesh->mTextureCoords[i] = new aiVector3D[pMesh->mNumVertices];
        pMesh->mNumUVComponents[i] = 4;
    }

    map<int, vector<aiVertexWeight>> bone_vertex_map;

    // fill in contents and create bones
    for (int index = 0; index < indexCount; index++) {
        const pmx::PmxVertex *v =
                &pModel->vertices[pModel->indices[indexStart + index]];
        const float *position = v->position;
        pMesh->mVertices[index].Set(position[0], position[1], position[2]);
        const float *normal = v->normal;

        pMesh->mNormals[index].Set(normal[0], normal[1], normal[2]);
        pMesh->mTextureCoords[0][index].x = v->uv[0];
        pMesh->mTextureCoords[0][index].y = v->uv[1];

        for (int i = 1; i <= pModel->setting.uv; i++) {
            // TODO: wrong here? use quaternion transform?
            pMesh->mTextureCoords[i][index].x = v->uva[i][0];
            pMesh->mTextureCoords[i][index].y = v->uva[i][1];
        }

        // handle bone map
        const auto vsBDEF1_ptr =
                dynamic_cast<pmx::PmxVertexSkinningBDEF1 *>(v->skinning.get());
        const auto vsBDEF2_ptr =
                dynamic_cast<pmx::PmxVertexSkinningBDEF2 *>(v->skinning.get());
        const auto vsBDEF4_ptr =
                dynamic_cast<pmx::PmxVertexSkinningBDEF4 *>(v->skinning.get());
        const auto vsSDEF_ptr =
                dynamic_cast<pmx::PmxVertexSkinningSDEF *>(v->skinning.get());
        switch (v->skinning_type) {
        case pmx::PmxVertexSkinningType::BDEF1:
            bone_vertex_map[vsBDEF1_ptr->bone_index].push_back(
                    aiVertexWeight(index, 1.0));
            break;
        case pmx::PmxVertexSkinningType::BDEF2:
            bone_vertex_map[vsBDEF2_ptr->bone_index1].push_back(
                    aiVertexWeight(index, vsBDEF2_ptr->bone_weight));
            bone_vertex_map[vsBDEF2_ptr->bone_index2].push_back(
                    aiVertexWeight(index, 1.0f - vsBDEF2_ptr->bone_weight));
            break;
        case pmx::PmxVertexSkinningType::BDEF4:
            bone_vertex_map[vsBDEF4_ptr->bone_index1].push_back(
                    aiVertexWeight(index, vsBDEF4_ptr->bone_weight1));
            bone_vertex_map[vsBDEF4_ptr->bone_index2].push_back(
                    aiVertexWeight(index, vsBDEF4_ptr->bone_weight2));
            bone_vertex_map[vsBDEF4_ptr->bone_index3].push_back(
                    aiVertexWeight(index, vsBDEF4_ptr->bone_weight3));
            bone_vertex_map[vsBDEF4_ptr->bone_index4].push_back(
                    aiVertexWeight(index, vsBDEF4_ptr->bone_weight4));
            break;
        case pmx::PmxVertexSkinningType::SDEF: // TODO: how to use sdef_c, sdef_r0,
                // sdef_r1?
            bone_vertex_map[vsSDEF_ptr->bone_index1].push_back(
                    aiVertexWeight(index, vsSDEF_ptr->bone_weight));
            bone_vertex_map[vsSDEF_ptr->bone_index2].push_back(
                    aiVertexWeight(index, 1.0f - vsSDEF_ptr->bone_weight));
            break;
        case pmx::PmxVertexSkinningType::QDEF:
            const auto vsQDEF_ptr =
                    dynamic_cast<pmx::PmxVertexSkinningQDEF *>(v->skinning.get());
            bone_vertex_map[vsQDEF_ptr->bone_index1].push_back(
                    aiVertexWeight(index, vsQDEF_ptr->bone_weight1));
            bone_vertex_map[vsQDEF_ptr->bone_index2].push_back(
                    aiVertexWeight(index, vsQDEF_ptr->bone_weight2));
            bone_vertex_map[vsQDEF_ptr->bone_index3].push_back(
                    aiVertexWeight(index, vsQDEF_ptr->bone_weight3));
            bone_vertex_map[vsQDEF_ptr->bone_index4].push_back(
                    aiVertexWeight(index, vsQDEF_ptr->bone_weight4));
            break;
        }
    }

    // make all bones for each mesh
    // assign bone weights to skinned bones (otherwise just initialize)
    auto bone_ptr_ptr = new aiBone *[pModel->bone_count];
    pMesh->mNumBones = pModel->bone_count;
    pMesh->mBones = bone_ptr_ptr;
    for (auto ii = 0; ii < pModel->bone_count; ++ii) {
        auto pBone = new aiBone;
        const auto &pmxBone = pModel->bones[ii];
        pBone->mName = pmxBone.bone_name;
        aiVector3D pos(pmxBone.position[0], pmxBone.position[1], pmxBone.position[2]);
        aiMatrix4x4::Translation(-pos, pBone->mOffsetMatrix);
        auto it = bone_vertex_map.find(ii);
        if (it != bone_vertex_map.end()) {
            pBone->mNumWeights = static_cast<unsigned int>(it->second.size());
            pBone->mWeights = new aiVertexWeight[pBone->mNumWeights];
            for (unsigned int j = 0; j < pBone->mNumWeights; j++) {
                pBone->mWeights[j] = it->second[j];
            }
        }
        bone_ptr_ptr[ii] = pBone;
    }

    return pMesh;
}

// ------------------------------------------------------------------------------------------------
aiMaterial *MMDImporter::CreateMaterial(const pmx::PmxMaterial *pMat,
        const pmx::PmxModel *pModel) {
    aiMaterial *mat = new aiMaterial();
    aiString name(pMat->material_english_name);
    mat->AddProperty(&name, AI_MATKEY_NAME);

    aiColor3D diffuse(pMat->diffuse[0], pMat->diffuse[1], pMat->diffuse[2]);
    mat->AddProperty(&diffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
    aiColor3D specular(pMat->specular[0], pMat->specular[1], pMat->specular[2]);
    mat->AddProperty(&specular, 1, AI_MATKEY_COLOR_SPECULAR);
    aiColor3D ambient(pMat->ambient[0], pMat->ambient[1], pMat->ambient[2]);
    mat->AddProperty(&ambient, 1, AI_MATKEY_COLOR_AMBIENT);

    float opacity = pMat->diffuse[3];
    mat->AddProperty(&opacity, 1, AI_MATKEY_OPACITY);
    float shininess = pMat->specularlity;
    mat->AddProperty(&shininess, 1, AI_MATKEY_SHININESS_STRENGTH);

    if (pMat->diffuse_texture_index >= 0) {
        aiString texture_path(pModel->textures[pMat->diffuse_texture_index]);
        mat->AddProperty(&texture_path, AI_MATKEY_TEXTURE(aiTextureType_DIFFUSE, 0));
    }

    int mapping_uvwsrc = 0;
    mat->AddProperty(&mapping_uvwsrc, 1,
            AI_MATKEY_UVWSRC(aiTextureType_DIFFUSE, 0));

    return mat;
}

// ------------------------------------------------------------------------------------------------

} // Namespace Assimp

#endif // !! ASSIMP_BUILD_NO_MMD_IMPORTER