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*/

/** @file Implementation of the LWO importer class for the older LWOB

    file formats, including materials */

#ifndef ASSIMP_BUILD_NO_LWO_IMPORTER

// Internal headers

#include "LWOLoader.h"

using namespace Assimp;

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

void LWOImporter::LoadLWOBFile() {

    LE_NCONST uint8_t* const end = mFileBuffer + fileSize;

    bool running = true;

    while (running) {

        if (mFileBuffer + sizeof(IFF::ChunkHeader) > end)

            break;

        const IFF::ChunkHeader head = IFF::LoadChunk(mFileBuffer);

        if (mFileBuffer + head.length > end) {

            throw DeadlyImportError("LWOB: Invalid chunk length");

        }

        uint8_t* const next = mFileBuffer+head.length;

        switch (head.type) {

            // vertex list

            case AI_LWO_PNTS: {

                if (!mCurLayer->mTempPoints.empty())

                    ASSIMP_LOG_WARN("LWO: PNTS chunk encountered twice");

                else

                    LoadLWOPoints(head.length);

                } break;

            case AI_LWO_POLS: {                 // face list

                    if (!mCurLayer->mFaces.empty())

                        ASSIMP_LOG_WARN("LWO: POLS chunk encountered twice");

                    else

                        LoadLWOBPolygons(head.length);

                } break;

            case AI_LWO_SRFS: // list of tags

                {

                    if (!mTags->empty())

                        ASSIMP_LOG_WARN("LWO: SRFS chunk encountered twice");

                    else

                        LoadLWOTags(head.length);

                } break;

            case AI_LWO_SURF: // surface chunk

                {

                    LoadLWOBSurface(head.length);

                } break;

            default:

                break;

        }

        mFileBuffer = next;

    }

}

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

void LWOImporter::LoadLWOBPolygons(unsigned int length) {

    // first find out how many faces and vertices we'll finally need

    LE_NCONST uint16_t* const end   = (LE_NCONST uint16_t*)(mFileBuffer+length);

    LE_NCONST uint16_t* cursor      = (LE_NCONST uint16_t*)mFileBuffer;

    // perform endianness conversions

#ifndef AI_BUILD_BIG_ENDIAN

    while (cursor < end)ByteSwap::Swap2(cursor++);

    cursor = (LE_NCONST uint16_t*)mFileBuffer;

#endif

    unsigned int iNumFaces = 0,iNumVertices = 0;

    CountVertsAndFacesLWOB(iNumVertices,iNumFaces,cursor,end);

    // allocate the output array and copy face indices

    if (iNumFaces) {

        cursor = (LE_NCONST uint16_t*)mFileBuffer;

        mCurLayer->mFaces.resize(iNumFaces);

        FaceList::iterator it = mCurLayer->mFaces.begin();

        CopyFaceIndicesLWOB(it,cursor,end);

    }

}

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

void LWOImporter::CountVertsAndFacesLWOB(unsigned int& verts, unsigned int& faces,

    LE_NCONST uint16_t*& cursor, const uint16_t* const end, unsigned int max) {

    while (cursor < end && max--) {

        uint16_t numIndices;

        // must have 2 shorts left for numIndices and surface

        if (end - cursor < 2) {

            throw DeadlyImportError("LWOB: Unexpected end of file");

        }

        ::memcpy(&numIndices, cursor++, 2);

        // must have enough left for indices and surface

        if (end - cursor < (1 + numIndices)) {

            throw DeadlyImportError("LWOB: Unexpected end of file");

        }

        verts += numIndices;

        faces++;

        cursor += numIndices;

        int16_t surface;

        ::memcpy(&surface, cursor++, 2);

        if (surface < 0) {

            // there are detail polygons

            ::memcpy(&numIndices, cursor++, 2);

            CountVertsAndFacesLWOB(verts,faces,cursor,end,numIndices);

        }

    }

}

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

void LWOImporter::CopyFaceIndicesLWOB(FaceList::iterator &it,

    LE_NCONST uint16_t*& cursor,

    const uint16_t* const end,

    unsigned int max) {

    while (cursor < end && max--) {

        LWO::Face& face = *it;++it;

        uint16_t numIndices;

        ::memcpy(&numIndices, cursor++, 2);

        face.mNumIndices = numIndices;

        if(face.mNumIndices) {

            if (cursor + face.mNumIndices >= end) {

                break;

            }

            face.mIndices = new unsigned int[face.mNumIndices];

            for (unsigned int i = 0; i < face.mNumIndices;++i) {

                unsigned int & mi = face.mIndices[i];

                uint16_t index;

                ::memcpy(&index, cursor++, 2);

                mi = index;

                if (mi >= mCurLayer->mTempPoints.size()) {

                    ASSIMP_LOG_WARN("LWOB: face index is out of range");

                    mi = mCurLayer->mTempPoints.empty() ? 0 : (unsigned int)(mCurLayer->mTempPoints.size() - 1);

                }

            }

        } else {

            ASSIMP_LOG_WARN("LWOB: Face has 0 indices");

        }

        int16_t surface;

        ::memcpy(&surface, cursor++, 2);

        if (surface < 0) {

            surface = -surface;

            // there are detail polygons.

            uint16_t numPolygons;

            ::memcpy(&numPolygons, cursor++, 2);

            if (cursor < end) {

                CopyFaceIndicesLWOB(it,cursor,end,numPolygons);

            }

        }

        face.surfaceIndex = surface-1;

    }

}

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

LWO::Texture* LWOImporter::SetupNewTextureLWOB(LWO::TextureList& list,unsigned int size) {

    list.emplace_back();

    LWO::Texture* tex = &list.back();

    std::string type;

    GetS0(type,size);

    const char* s = type.c_str();

    if(strstr(s, "Image Map")) {

        // Determine mapping type

        if(strstr(s, "Planar"))

            tex->mapMode = LWO::Texture::Planar;

        else if(strstr(s, "Cylindrical"))

            tex->mapMode = LWO::Texture::Cylindrical;

        else if(strstr(s, "Spherical"))

            tex->mapMode = LWO::Texture::Spherical;

        else if(strstr(s, "Cubic"))

            tex->mapMode = LWO::Texture::Cubic;

        else if(strstr(s, "Front"))

            tex->mapMode = LWO::Texture::FrontProjection;

    } else {

        // procedural or gradient, not supported

        ASSIMP_LOG_ERROR("LWOB: Unsupported legacy texture: ", type);

    }

    return tex;

}

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

void LWOImporter::LoadLWOBSurface(unsigned int size) {

    LE_NCONST uint8_t* const end = mFileBuffer + size;

    mSurfaces->push_back( LWO::Surface () );

    LWO::Surface& surf = mSurfaces->back();

    LWO::Texture *pTex = nullptr;

    GetS0(surf.mName,size);

    bool running = true;

    while (running)    {

        if (mFileBuffer + 6 >= end)

            break;

        IFF::SubChunkHeader head = IFF::LoadSubChunk(mFileBuffer);

        /*  A single test file (sonycam.lwo) seems to have invalid surface chunks.

         *  I'm assuming it's the fault of a single, unknown exporter so there are

         *  probably THOUSANDS of them. Here's a dirty workaround:

         *

         *  We don't break if the chunk limit is exceeded. Instead, we're computing

         *  how much storage is actually left and work with this value from now on.

         */

        if (mFileBuffer + head.length > end) {

            ASSIMP_LOG_ERROR("LWOB: Invalid surface chunk length. Trying to continue.");

            head.length = (uint16_t) (end - mFileBuffer);

        }

        uint8_t* const next = mFileBuffer+head.length;

        switch (head.type) {

            // diffuse color

            case AI_LWO_COLR:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,COLR,3);

                    surf.mColor.r = GetU1() / 255.0f;

                    surf.mColor.g = GetU1() / 255.0f;

                    surf.mColor.b = GetU1() / 255.0f;

                    break;

                }

            // diffuse strength ...

            case AI_LWO_DIFF:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,DIFF,2);

                    surf.mDiffuseValue = GetU2() / 255.0f;

                    break;

                }

            // specular strength ...

            case AI_LWO_SPEC:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,SPEC,2);

                    surf.mSpecularValue = GetU2() / 255.0f;

                    break;

                }

            // luminosity ...

            case AI_LWO_LUMI:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,LUMI,2);

                    surf.mLuminosity = GetU2() / 255.0f;

                    break;

                }

            // transparency

            case AI_LWO_TRAN:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,TRAN,2);

                    surf.mTransparency = GetU2() / 255.0f;

                    break;

                }

            // surface flags

            case AI_LWO_FLAG:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,FLAG,2);

                    uint16_t flag = GetU2();

                    if (flag & 0x4 )   surf.mMaximumSmoothAngle = 1.56207f;

                    if (flag & 0x8 )   surf.mColorHighlights = 1.f;

                    if (flag & 0x100)  surf.bDoubleSided = true;

                    break;

                }

            // maximum smoothing angle

            case AI_LWO_SMAN:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,SMAN,4);

                    surf.mMaximumSmoothAngle = std::fabs( GetF4() );

                    break;

                }

            // glossiness

            case AI_LWO_GLOS:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,GLOS,2);

                    surf.mGlossiness = (float)GetU2();

                    break;

                }

            // color texture

            case AI_LWO_CTEX:

                {

                    pTex = SetupNewTextureLWOB(surf.mColorTextures,

                        head.length);

                    break;

                }

            // diffuse texture

            case AI_LWO_DTEX:

                {

                    pTex = SetupNewTextureLWOB(surf.mDiffuseTextures,

                        head.length);

                    break;

                }

            // specular texture

            case AI_LWO_STEX:

                {

                    pTex = SetupNewTextureLWOB(surf.mSpecularTextures,

                        head.length);

                    break;

                }

            // bump texture

            case AI_LWO_BTEX:

                {

                    pTex = SetupNewTextureLWOB(surf.mBumpTextures,

                        head.length);

                    break;

                }

            // transparency texture

            case AI_LWO_TTEX:

                {

                    pTex = SetupNewTextureLWOB(surf.mOpacityTextures,

                        head.length);

                    break;

                }

            // texture path

            case AI_LWO_TIMG:

                {

                    if (pTex)   {

                        GetS0(pTex->mFileName,head.length);

                    } else {

                        ASSIMP_LOG_WARN("LWOB: Unexpected TIMG chunk");

                    }

                    break;

                }

            // texture strength

            case AI_LWO_TVAL:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,TVAL,1);

                    if (pTex)   {

                        pTex->mStrength = (float)GetU1()/ 255.f;

                    } else {

                        ASSIMP_LOG_ERROR("LWOB: Unexpected TVAL chunk");

                    }

                    break;

                }

            // texture flags

            case AI_LWO_TFLG:

                {

                    AI_LWO_VALIDATE_CHUNK_LENGTH(head.length,TFLG,2);

                    if (nullptr != pTex) {

                        const uint16_t s = GetU2();

                        if (s & 1)

                            pTex->majorAxis = LWO::Texture::AXIS_X;

                        else if (s & 2)

                            pTex->majorAxis = LWO::Texture::AXIS_Y;

                        else if (s & 4)

                            pTex->majorAxis = LWO::Texture::AXIS_Z;

                        if (s & 16) {

                            ASSIMP_LOG_WARN("LWOB: Ignoring \'negate\' flag on texture");

                        }

                    }

                    else {

                        ASSIMP_LOG_WARN("LWOB: Unexpected TFLG chunk");

                    }

                    break;

                }

        }

        mFileBuffer = next;

    }

}

#endif // !! ASSIMP_BUILD_NO_LWO_IMPORTER