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/** @file  MD5Parser.cpp
 *  @brief Implementation of the MD5 parser class
 */

// internal headers
#include "AssetLib/MD5/MD5Loader.h"
#include "Material/MaterialSystem.h"

#include <assimp/ParsingUtils.h>
#include <assimp/StringComparison.h>
#include <assimp/fast_atof.h>
#include <assimp/mesh.h>
#include <assimp/DefaultLogger.hpp>

using namespace Assimp;
using namespace Assimp::MD5;

// ------------------------------------------------------------------------------------------------
// Parse the segment structure fo a MD5 file
MD5Parser::MD5Parser(char *_buffer, unsigned int _fileSize) {
    ai_assert(nullptr != _buffer);
    ai_assert(0 != _fileSize);

    buffer = _buffer;
    fileSize = _fileSize;
    lineNumber = 0;

    ASSIMP_LOG_DEBUG("MD5Parser begin");

    // parse the file header
    ParseHeader();

    // and read all sections until we're finished
    bool running = true;
    while (running) {
        mSections.push_back(Section());
        Section &sec = mSections.back();
        if (!ParseSection(sec)) {
            break;
        }
    }

    if (!DefaultLogger::isNullLogger()) {
        char szBuffer[128]; // should be sufficiently large
        ::ai_snprintf(szBuffer, 128, "MD5Parser end. Parsed %i sections", (int)mSections.size());
        ASSIMP_LOG_DEBUG(szBuffer);
    }
}

// ------------------------------------------------------------------------------------------------
// Report error to the log stream
/*static*/ AI_WONT_RETURN void MD5Parser::ReportError(const char *error, unsigned int line) {
    char szBuffer[1024];
    ::ai_snprintf(szBuffer, 1024, "[MD5] Line %u: %s", line, error);
    throw DeadlyImportError(szBuffer);
}

// ------------------------------------------------------------------------------------------------
// Report warning to the log stream
/*static*/ void MD5Parser::ReportWarning(const char *warn, unsigned int line) {
    char szBuffer[1024];
    ::sprintf(szBuffer, "[MD5] Line %u: %s", line, warn);
    ASSIMP_LOG_WARN(szBuffer);
}

// ------------------------------------------------------------------------------------------------
// Parse and validate the MD5 header
void MD5Parser::ParseHeader() {
    // parse and validate the file version
    SkipSpaces();
    if (!TokenMatch(buffer, "MD5Version", 10)) {
        ReportError("Invalid MD5 file: MD5Version tag has not been found");
    }
    SkipSpaces();
    unsigned int iVer = ::strtoul10(buffer, (const char **)&buffer);
    if (10 != iVer) {
        ReportError("MD5 version tag is unknown (10 is expected)");
    }
    SkipLine();

    // print the command line options to the console
    // FIX: can break the log length limit, so we need to be careful
    char *sz = buffer;
    while (!IsLineEnd(*buffer++))
        ;
    ASSIMP_LOG_INFO(std::string(sz, std::min((uintptr_t)MAX_LOG_MESSAGE_LENGTH, (uintptr_t)(buffer - sz))));
    SkipSpacesAndLineEnd();
}

// ------------------------------------------------------------------------------------------------
// Recursive MD5 parsing function
bool MD5Parser::ParseSection(Section &out) {
    // store the current line number for use in error messages
    out.iLineNumber = lineNumber;

    // first parse the name of the section
    char *sz = buffer;
    while (!IsSpaceOrNewLine(*buffer))
        buffer++;
    out.mName = std::string(sz, (uintptr_t)(buffer - sz));
    SkipSpaces();

    bool running = true;
    while (running) {
        if ('{' == *buffer) {
            // it is a normal section so read all lines
            buffer++;
            bool run = true;
            while (run) {
                if (!SkipSpacesAndLineEnd()) {
                    return false; // seems this was the last section
                }
                if ('}' == *buffer) {
                    buffer++;
                    break;
                }

                out.mElements.push_back(Element());
                Element &elem = out.mElements.back();

                elem.iLineNumber = lineNumber;
                elem.szStart = buffer;

                // terminate the line with zero
                while (!IsLineEnd(*buffer))
                    buffer++;
                if (*buffer) {
                    ++lineNumber;
                    *buffer++ = '\0';
                }
            }
            break;
        } else if (!IsSpaceOrNewLine(*buffer)) {
            // it is an element at global scope. Parse its value and go on
            sz = buffer;
            while (!IsSpaceOrNewLine(*buffer++))
                ;
            out.mGlobalValue = std::string(sz, (uintptr_t)(buffer - sz));
            continue;
        }
        break;
    }
    return SkipSpacesAndLineEnd();
}

// ------------------------------------------------------------------------------------------------
// Some dirty macros just because they're so funny and easy to debug

// skip all spaces ... handle EOL correctly
#define AI_MD5_SKIP_SPACES() \
    if (!SkipSpaces(&sz))    \
        MD5Parser::ReportWarning("Unexpected end of line", elem.iLineNumber);

// read a triple float in brackets: (1.0 1.0 1.0)
#define AI_MD5_READ_TRIPLE(vec)                                                         \
    AI_MD5_SKIP_SPACES();                                                               \
    if ('(' != *sz++)                                                                   \
        MD5Parser::ReportWarning("Unexpected token: ( was expected", elem.iLineNumber); \
    AI_MD5_SKIP_SPACES();                                                               \
    sz = fast_atoreal_move<float>(sz, (float &)vec.x);                                  \
    AI_MD5_SKIP_SPACES();                                                               \
    sz = fast_atoreal_move<float>(sz, (float &)vec.y);                                  \
    AI_MD5_SKIP_SPACES();                                                               \
    sz = fast_atoreal_move<float>(sz, (float &)vec.z);                                  \
    AI_MD5_SKIP_SPACES();                                                               \
    if (')' != *sz++)                                                                   \
        MD5Parser::ReportWarning("Unexpected token: ) was expected", elem.iLineNumber);

// parse a string, enclosed in quotation marks or not
#define AI_MD5_PARSE_STRING(out)                                                   \
    bool bQuota = (*sz == '\"');                                                   \
    const char *szStart = sz;                                                      \
    while (!IsSpaceOrNewLine(*sz))                                                 \
        ++sz;                                                                      \
    const char *szEnd = sz;                                                        \
    if (bQuota) {                                                                  \
        szStart++;                                                                 \
        if ('\"' != *(szEnd -= 1)) {                                               \
            MD5Parser::ReportWarning("Expected closing quotation marks in string", \
                    elem.iLineNumber);                                             \
            continue;                                                              \
        }                                                                          \
    }                                                                              \
    out.length = (size_t)(szEnd - szStart);                                        \
    ::memcpy(out.data, szStart, out.length);                                       \
    out.data[out.length] = '\0';

// parse a string, enclosed in quotation marks
#define AI_MD5_PARSE_STRING_IN_QUOTATION(out)  \
    while ('\"' != *sz)                        \
        ++sz;                                  \
    const char *szStart = ++sz;                \
    while ('\"' != *sz)                        \
        ++sz;                                  \
    const char *szEnd = (sz++);                \
    out.length = (ai_uint32)(szEnd - szStart); \
    ::memcpy(out.data, szStart, out.length);   \
    out.data[out.length] = '\0';
// ------------------------------------------------------------------------------------------------
// .MD5MESH parsing function
MD5MeshParser::MD5MeshParser(SectionList &mSections) {
    ASSIMP_LOG_DEBUG("MD5MeshParser begin");

    // now parse all sections
    for (SectionList::const_iterator iter = mSections.begin(), iterEnd = mSections.end(); iter != iterEnd; ++iter) {
        if ((*iter).mName == "numMeshes") {
            mMeshes.reserve(::strtoul10((*iter).mGlobalValue.c_str()));
        } else if ((*iter).mName == "numJoints") {
            mJoints.reserve(::strtoul10((*iter).mGlobalValue.c_str()));
        } else if ((*iter).mName == "joints") {
            // "origin" -1 ( -0.000000 0.016430 -0.006044 ) ( 0.707107 0.000000 0.707107 )
            for (const auto &elem : (*iter).mElements) {
                mJoints.push_back(BoneDesc());
                BoneDesc &desc = mJoints.back();

                const char *sz = elem.szStart;
                AI_MD5_PARSE_STRING_IN_QUOTATION(desc.mName);
                AI_MD5_SKIP_SPACES();

                // negative values, at least -1, is allowed here
                desc.mParentIndex = (int)strtol10(sz, &sz);

                AI_MD5_READ_TRIPLE(desc.mPositionXYZ);
                AI_MD5_READ_TRIPLE(desc.mRotationQuat); // normalized quaternion, so w is not there
            }
        } else if ((*iter).mName == "mesh") {
            mMeshes.push_back(MeshDesc());
            MeshDesc &desc = mMeshes.back();

            for (const auto &elem : (*iter).mElements) {
                const char *sz = elem.szStart;

                // shader attribute
                if (TokenMatch(sz, "shader", 6)) {
                    AI_MD5_SKIP_SPACES();
                    AI_MD5_PARSE_STRING_IN_QUOTATION(desc.mShader);
                }
                // numverts attribute
                else if (TokenMatch(sz, "numverts", 8)) {
                    AI_MD5_SKIP_SPACES();
                    desc.mVertices.resize(strtoul10(sz));
                }
                // numtris attribute
                else if (TokenMatch(sz, "numtris", 7)) {
                    AI_MD5_SKIP_SPACES();
                    desc.mFaces.resize(strtoul10(sz));
                }
                // numweights attribute
                else if (TokenMatch(sz, "numweights", 10)) {
                    AI_MD5_SKIP_SPACES();
                    desc.mWeights.resize(strtoul10(sz));
                }
                // vert attribute
                // "vert 0 ( 0.394531 0.513672 ) 0 1"
                else if (TokenMatch(sz, "vert", 4)) {
                    AI_MD5_SKIP_SPACES();
                    const unsigned int idx = ::strtoul10(sz, &sz);
                    AI_MD5_SKIP_SPACES();
                    if (idx >= desc.mVertices.size())
                        desc.mVertices.resize(idx + 1);

                    VertexDesc &vert = desc.mVertices[idx];
                    if ('(' != *sz++)
                        MD5Parser::ReportWarning("Unexpected token: ( was expected", elem.iLineNumber);
                    AI_MD5_SKIP_SPACES();
                    sz = fast_atoreal_move<float>(sz, (float &)vert.mUV.x);
                    AI_MD5_SKIP_SPACES();
                    sz = fast_atoreal_move<float>(sz, (float &)vert.mUV.y);
                    AI_MD5_SKIP_SPACES();
                    if (')' != *sz++)
                        MD5Parser::ReportWarning("Unexpected token: ) was expected", elem.iLineNumber);
                    AI_MD5_SKIP_SPACES();
                    vert.mFirstWeight = ::strtoul10(sz, &sz);
                    AI_MD5_SKIP_SPACES();
                    vert.mNumWeights = ::strtoul10(sz, &sz);
                }
                // tri attribute
                // "tri 0 15 13 12"
                else if (TokenMatch(sz, "tri", 3)) {
                    AI_MD5_SKIP_SPACES();
                    const unsigned int idx = strtoul10(sz, &sz);
                    if (idx >= desc.mFaces.size())
                        desc.mFaces.resize(idx + 1);

                    aiFace &face = desc.mFaces[idx];
                    face.mIndices = new unsigned int[face.mNumIndices = 3];
                    for (unsigned int i = 0; i < 3; ++i) {
                        AI_MD5_SKIP_SPACES();
                        face.mIndices[i] = strtoul10(sz, &sz);
                    }
                }
                // weight attribute
                // "weight 362 5 0.500000 ( -3.553583 11.893474 9.719339 )"
                else if (TokenMatch(sz, "weight", 6)) {
                    AI_MD5_SKIP_SPACES();
                    const unsigned int idx = strtoul10(sz, &sz);
                    AI_MD5_SKIP_SPACES();
                    if (idx >= desc.mWeights.size())
                        desc.mWeights.resize(idx + 1);

                    WeightDesc &weight = desc.mWeights[idx];
                    weight.mBone = strtoul10(sz, &sz);
                    AI_MD5_SKIP_SPACES();
                    sz = fast_atoreal_move<float>(sz, weight.mWeight);
                    AI_MD5_READ_TRIPLE(weight.vOffsetPosition);
                }
            }
        }
    }
    ASSIMP_LOG_DEBUG("MD5MeshParser end");
}

// ------------------------------------------------------------------------------------------------
// .MD5ANIM parsing function
MD5AnimParser::MD5AnimParser(SectionList &mSections) {
    ASSIMP_LOG_DEBUG("MD5AnimParser begin");

    fFrameRate = 24.0f;
    mNumAnimatedComponents = UINT_MAX;
    for (SectionList::const_iterator iter = mSections.begin(), iterEnd = mSections.end(); iter != iterEnd; ++iter) {
        if ((*iter).mName == "hierarchy") {
            // "sheath" 0 63 6
            for (const auto &elem : (*iter).mElements) {
                mAnimatedBones.push_back(AnimBoneDesc());
                AnimBoneDesc &desc = mAnimatedBones.back();

                const char *sz = elem.szStart;
                AI_MD5_PARSE_STRING_IN_QUOTATION(desc.mName);
                AI_MD5_SKIP_SPACES();

                // parent index - negative values are allowed (at least -1)
                desc.mParentIndex = ::strtol10(sz, &sz);

                // flags (highest is 2^6-1)
                AI_MD5_SKIP_SPACES();
                if (63 < (desc.iFlags = ::strtoul10(sz, &sz))) {
                    MD5Parser::ReportWarning("Invalid flag combination in hierarchy section", elem.iLineNumber);
                }
                AI_MD5_SKIP_SPACES();

                // index of the first animation keyframe component for this joint
                desc.iFirstKeyIndex = ::strtoul10(sz, &sz);
            }
        } else if ((*iter).mName == "baseframe") {
            // ( -0.000000 0.016430 -0.006044 ) ( 0.707107 0.000242 0.707107 )
            for (const auto &elem : (*iter).mElements) {
                const char *sz = elem.szStart;

                mBaseFrames.push_back(BaseFrameDesc());
                BaseFrameDesc &desc = mBaseFrames.back();

                AI_MD5_READ_TRIPLE(desc.vPositionXYZ);
                AI_MD5_READ_TRIPLE(desc.vRotationQuat);
            }
        } else if ((*iter).mName == "frame") {
            if (!(*iter).mGlobalValue.length()) {
                MD5Parser::ReportWarning("A frame section must have a frame index", (*iter).iLineNumber);
                continue;
            }

            mFrames.push_back(FrameDesc());
            FrameDesc &desc = mFrames.back();
            desc.iIndex = strtoul10((*iter).mGlobalValue.c_str());

            // we do already know how much storage we will presumably need
            if (UINT_MAX != mNumAnimatedComponents) {
                desc.mValues.reserve(mNumAnimatedComponents);
            }

            // now read all elements (continuous list of floats)
            for (const auto &elem : (*iter).mElements) {
                const char *sz = elem.szStart;
                while (SkipSpacesAndLineEnd(&sz)) {
                    float f;
                    sz = fast_atoreal_move<float>(sz, f);
                    desc.mValues.push_back(f);
                }
            }
        } else if ((*iter).mName == "numFrames") {
            mFrames.reserve(strtoul10((*iter).mGlobalValue.c_str()));
        } else if ((*iter).mName == "numJoints") {
            const unsigned int num = strtoul10((*iter).mGlobalValue.c_str());
            mAnimatedBones.reserve(num);

            // try to guess the number of animated components if that element is not given
            if (UINT_MAX == mNumAnimatedComponents) {
                mNumAnimatedComponents = num * 6;
            }
        } else if ((*iter).mName == "numAnimatedComponents") {
            mAnimatedBones.reserve(strtoul10((*iter).mGlobalValue.c_str()));
        } else if ((*iter).mName == "frameRate") {
            fast_atoreal_move<float>((*iter).mGlobalValue.c_str(), fFrameRate);
        }
    }
    ASSIMP_LOG_DEBUG("MD5AnimParser end");
}

// ------------------------------------------------------------------------------------------------
// .MD5CAMERA parsing function
MD5CameraParser::MD5CameraParser(SectionList &mSections) {
    ASSIMP_LOG_DEBUG("MD5CameraParser begin");
    fFrameRate = 24.0f;

    for (SectionList::const_iterator iter = mSections.begin(), iterEnd = mSections.end(); iter != iterEnd; ++iter) {
        if ((*iter).mName == "numFrames") {
            frames.reserve(strtoul10((*iter).mGlobalValue.c_str()));
        } else if ((*iter).mName == "frameRate") {
            fFrameRate = fast_atof((*iter).mGlobalValue.c_str());
        } else if ((*iter).mName == "numCuts") {
            cuts.reserve(strtoul10((*iter).mGlobalValue.c_str()));
        } else if ((*iter).mName == "cuts") {
            for (const auto &elem : (*iter).mElements) {
                cuts.push_back(strtoul10(elem.szStart) + 1);
            }
        } else if ((*iter).mName == "camera") {
            for (const auto &elem : (*iter).mElements) {
                const char *sz = elem.szStart;

                frames.push_back(CameraAnimFrameDesc());
                CameraAnimFrameDesc &cur = frames.back();
                AI_MD5_READ_TRIPLE(cur.vPositionXYZ);
                AI_MD5_READ_TRIPLE(cur.vRotationQuat);
                AI_MD5_SKIP_SPACES();
                cur.fFOV = fast_atof(sz);
            }
        }
    }
    ASSIMP_LOG_DEBUG("MD5CameraParser end");
}
