assimp.assimp/code/PostProcessing/EmbedTexturesProcess.cpp

/*
Open Asset Import Library (assimp)
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*/

#include "EmbedTexturesProcess.h"
#include <assimp/IOStream.hpp>
#include <assimp/IOSystem.hpp>
#include <assimp/ParsingUtils.h>
#include "ProcessHelper.h"

#include <fstream>
#include <algorithm>

using namespace Assimp;

bool EmbedTexturesProcess::IsActive(unsigned int pFlags) const {
    return (pFlags & aiProcess_EmbedTextures) != 0;
}

void EmbedTexturesProcess::SetupProperties(const Importer* pImp) {
    mRootPath = pImp->GetPropertyString("sourceFilePath");
    mRootPath = mRootPath.substr(0, mRootPath.find_last_of("\\/") + 1u);
    mIOHandler = pImp->GetIOHandler();
}

void EmbedTexturesProcess::Execute(aiScene* pScene) {
    if (pScene == nullptr || pScene->mRootNode == nullptr || mIOHandler == nullptr){
        return;
    }

    aiString path;
    uint32_t embeddedTexturesCount = 0u;
    for (auto matId = 0u; matId < pScene->mNumMaterials; ++matId) {
        auto material = pScene->mMaterials[matId];

        for (auto ttId = 1u; ttId < AI_TEXTURE_TYPE_MAX; ++ttId) {
            auto tt = static_cast<aiTextureType>(ttId);
            auto texturesCount = material->GetTextureCount(tt);

            for (auto texId = 0u; texId < texturesCount; ++texId) {
                material->GetTexture(tt, texId, &path);
                if (path.data[0] == '*') continue; // Already embedded

                // Indeed embed
                if (addTexture(pScene, path.data)) {
                    auto embeddedTextureId = pScene->mNumTextures - 1u;
                    path.length = ::ai_snprintf(path.data, 1024, "*%u", embeddedTextureId);
                    material->AddProperty(&path, AI_MATKEY_TEXTURE(tt, texId));
                    embeddedTexturesCount++;
                }
            }
        }
    }

    ASSIMP_LOG_INFO("EmbedTexturesProcess finished. Embedded ", embeddedTexturesCount, " textures." );
}

std::string EmbedTexturesProcess::tryToFindValidPath(const std::string &imagePath) const
{
    // Test path directly
    if (mIOHandler->Exists(imagePath)) {
        return imagePath;
    }
    ASSIMP_LOG_WARN("EmbedTexturesProcess: Cannot find image: ", imagePath, ". Will try to find it in root folder.");

    // Test path in root path
    std::string testPath = mRootPath + imagePath;
    if (mIOHandler->Exists(testPath)) {
        return testPath;
    }

    // Test path basename in root path
    testPath = mRootPath + imagePath.substr(imagePath.find_last_of("\\/") + 1u);
    if (mIOHandler->Exists(testPath)) {
        return testPath;
    }

    // In unix systems, '\' is a valid file name character, but some files may use \ as a directory separator.
    // Try replacing '\' by '/'.
    if (mIOHandler->getOsSeparator() != '\\' && imagePath.find('\\') != std::string::npos) {
        ASSIMP_LOG_WARN("EmbedTexturesProcess: Cannot find image '", imagePath, "' in root folder. Will try replacing directory separators.");
        testPath = imagePath;
        std::replace(testPath.begin(), testPath.end(), '\\', mIOHandler->getOsSeparator());
        return tryToFindValidPath(testPath);
    }

    ASSIMP_LOG_ERROR("EmbedTexturesProcess: Unable to embed texture: ", imagePath, ".");
    return {};
}

bool EmbedTexturesProcess::addTexture(aiScene *pScene, const std::string &path) const {
    std::streampos imageSize = 0;
    std::string    imagePath = tryToFindValidPath(path);

    if (imagePath.empty()) {
        return false;
    }

    IOStream* pFile = mIOHandler->Open(imagePath);
    if (pFile == nullptr) {
        ASSIMP_LOG_ERROR("EmbedTexturesProcess: Unable to embed texture: ", path, ".");
        return false;
    }
    imageSize = pFile->FileSize();

    aiTexel* imageContent = new aiTexel[ 1ul + static_cast<unsigned long>( imageSize ) / sizeof(aiTexel)];
    pFile->Seek(0, aiOrigin_SET);
    pFile->Read(reinterpret_cast<char*>(imageContent), static_cast<size_t>(imageSize), 1);
    mIOHandler->Close(pFile);

    // Enlarging the textures table
    unsigned int textureId = pScene->mNumTextures++;
    auto oldTextures = pScene->mTextures;
    pScene->mTextures = new aiTexture*[pScene->mNumTextures];
    ::memmove(pScene->mTextures, oldTextures, sizeof(aiTexture*) * (pScene->mNumTextures - 1u));
    delete [] oldTextures;

    // Add the new texture
    auto pTexture = new aiTexture;
    pTexture->mHeight = 0; // Means that this is still compressed
    pTexture->mWidth = static_cast<uint32_t>(imageSize);
    pTexture->pcData = imageContent;

    auto extension = path.substr(path.find_last_of('.') + 1u);
    extension = ai_tolower(extension);
    if (extension == "jpeg") {
        extension = "jpg";
    }

    size_t len = extension.size();
    if (len > HINTMAXTEXTURELEN -1 ) {
        len = HINTMAXTEXTURELEN - 1;
    }
    ::strncpy(pTexture->achFormatHint, extension.c_str(), len);
    pScene->mTextures[textureId] = pTexture;

    return true;
}