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/** @file  ValidateDataStructure.cpp
 *  @brief Implementation of the post processing step to validate
 *    the data structure returned by Assimp.
 */

// internal headers
#include "ValidateDataStructure.h"
#include "ProcessHelper.h"
#include <assimp/BaseImporter.h>
#include <assimp/fast_atof.h>
#include <memory>

// CRT headers
#include <stdarg.h>

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
ValidateDSProcess::ValidateDSProcess() :
        mScene() {}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
ValidateDSProcess::~ValidateDSProcess() {}

// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool ValidateDSProcess::IsActive(unsigned int pFlags) const {
    return (pFlags & aiProcess_ValidateDataStructure) != 0;
}
// ------------------------------------------------------------------------------------------------
AI_WONT_RETURN void ValidateDSProcess::ReportError(const char *msg, ...) {
    ai_assert(nullptr != msg);

    va_list args;
    va_start(args, msg);

    char szBuffer[3000];
    const int iLen = vsprintf(szBuffer, msg, args);
    ai_assert(iLen > 0);

    va_end(args);

    throw DeadlyImportError("Validation failed: ", std::string(szBuffer, iLen));
}
// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::ReportWarning(const char *msg, ...) {
    ai_assert(nullptr != msg);

    va_list args;
    va_start(args, msg);

    char szBuffer[3000];
    const int iLen = vsprintf(szBuffer, msg, args);
    ai_assert(iLen > 0);

    va_end(args);
    ASSIMP_LOG_WARN("Validation warning: " + std::string(szBuffer, iLen));
}

// ------------------------------------------------------------------------------------------------
inline int HasNameMatch(const aiString &in, aiNode *node) {
    int result = (node->mName == in ? 1 : 0);
    for (unsigned int i = 0; i < node->mNumChildren; ++i) {
        result += HasNameMatch(in, node->mChildren[i]);
    }
    return result;
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline void ValidateDSProcess::DoValidation(T **parray, unsigned int size, const char *firstName, const char *secondName) {
    // validate all entries
    if (size) {
        if (!parray) {
            ReportError("aiScene::%s is nullptr (aiScene::%s is %i)",
                    firstName, secondName, size);
        }
        for (unsigned int i = 0; i < size; ++i) {
            if (!parray[i]) {
                ReportError("aiScene::%s[%i] is nullptr (aiScene::%s is %i)",
                        firstName, i, secondName, size);
            }
            Validate(parray[i]);
        }
    }
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline void ValidateDSProcess::DoValidationEx(T **parray, unsigned int size,
        const char *firstName, const char *secondName) {
    // validate all entries
    if (size) {
        if (!parray) {
            ReportError("aiScene::%s is nullptr (aiScene::%s is %i)",
                    firstName, secondName, size);
        }
        for (unsigned int i = 0; i < size; ++i) {
            if (!parray[i]) {
                ReportError("aiScene::%s[%u] is nullptr (aiScene::%s is %u)",
                        firstName, i, secondName, size);
            }
            Validate(parray[i]);

            // check whether there are duplicate names
            for (unsigned int a = i + 1; a < size; ++a) {
                if (parray[i]->mName == parray[a]->mName) {
                    ReportError("aiScene::%s[%u] has the same name as "
                                "aiScene::%s[%u]",
                            firstName, i, secondName, a);
                }
            }
        }
    }
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline void ValidateDSProcess::DoValidationWithNameCheck(T **array, unsigned int size, const char *firstName,
        const char *secondName) {
    // validate all entries
    DoValidationEx(array, size, firstName, secondName);

    for (unsigned int i = 0; i < size; ++i) {
        int res = HasNameMatch(array[i]->mName, mScene->mRootNode);
        if (0 == res) {
            const std::string name = static_cast<char *>(array[i]->mName.data);
            ReportError("aiScene::%s[%i] has no corresponding node in the scene graph (%s)",
                    firstName, i, name.c_str());
        } else if (1 != res) {
            const std::string name = static_cast<char *>(array[i]->mName.data);
            ReportError("aiScene::%s[%i]: there are more than one nodes with %s as name",
                    firstName, i, name.c_str());
        }
    }
}

// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void ValidateDSProcess::Execute(aiScene *pScene) {
    mScene = pScene;
    ASSIMP_LOG_DEBUG("ValidateDataStructureProcess begin");

    // validate the node graph of the scene
    Validate(pScene->mRootNode);

    // validate all meshes
    if (pScene->mNumMeshes) {
        DoValidation(pScene->mMeshes, pScene->mNumMeshes, "mMeshes", "mNumMeshes");
    } else if (!(mScene->mFlags & AI_SCENE_FLAGS_INCOMPLETE)) {
        ReportError("aiScene::mNumMeshes is 0. At least one mesh must be there");
    } else if (pScene->mMeshes) {
        ReportError("aiScene::mMeshes is non-null although there are no meshes");
    }

    // validate all animations
    if (pScene->mNumAnimations) {
        DoValidation(pScene->mAnimations, pScene->mNumAnimations,
                "mAnimations", "mNumAnimations");
    } else if (pScene->mAnimations) {
        ReportError("aiScene::mAnimations is non-null although there are no animations");
    }

    // validate all cameras
    if (pScene->mNumCameras) {
        DoValidationWithNameCheck(pScene->mCameras, pScene->mNumCameras,
                "mCameras", "mNumCameras");
    } else if (pScene->mCameras) {
        ReportError("aiScene::mCameras is non-null although there are no cameras");
    }

    // validate all lights
    if (pScene->mNumLights) {
        DoValidationWithNameCheck(pScene->mLights, pScene->mNumLights,
                "mLights", "mNumLights");
    } else if (pScene->mLights) {
        ReportError("aiScene::mLights is non-null although there are no lights");
    }

    // validate all textures
    if (pScene->mNumTextures) {
        DoValidation(pScene->mTextures, pScene->mNumTextures,
                "mTextures", "mNumTextures");
    } else if (pScene->mTextures) {
        ReportError("aiScene::mTextures is non-null although there are no textures");
    }

    // validate all materials
    if (pScene->mNumMaterials) {
        DoValidation(pScene->mMaterials, pScene->mNumMaterials, "mMaterials", "mNumMaterials");
    }
#if 0
    // NOTE: ScenePreprocessor generates a default material if none is there
    else if (!(mScene->mFlags & AI_SCENE_FLAGS_INCOMPLETE)) {
        ReportError("aiScene::mNumMaterials is 0. At least one material must be there");
    }
#endif
    else if (pScene->mMaterials) {
        ReportError("aiScene::mMaterials is non-null although there are no materials");
    }

    //  if (!has)ReportError("The aiScene data structure is empty");
    ASSIMP_LOG_DEBUG("ValidateDataStructureProcess end");
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiLight *pLight) {
    if (pLight->mType == aiLightSource_UNDEFINED)
        ReportWarning("aiLight::mType is aiLightSource_UNDEFINED");

    if (!pLight->mAttenuationConstant &&
            !pLight->mAttenuationLinear &&
            !pLight->mAttenuationQuadratic) {
        ReportWarning("aiLight::mAttenuationXXX - all are zero");
    }

    if (pLight->mAngleInnerCone > pLight->mAngleOuterCone)
        ReportError("aiLight::mAngleInnerCone is larger than aiLight::mAngleOuterCone");

    if (pLight->mColorDiffuse.IsBlack() && pLight->mColorAmbient.IsBlack() && pLight->mColorSpecular.IsBlack()) {
        ReportWarning("aiLight::mColorXXX - all are black and won't have any influence");
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiCamera *pCamera) {
    if (pCamera->mClipPlaneFar <= pCamera->mClipPlaneNear)
        ReportError("aiCamera::mClipPlaneFar must be >= aiCamera::mClipPlaneNear");

    // FIX: there are many 3ds files with invalid FOVs. No reason to
    // reject them at all ... a warning is appropriate.
    if (!pCamera->mHorizontalFOV || pCamera->mHorizontalFOV >= (float)AI_MATH_PI)
        ReportWarning("%f is not a valid value for aiCamera::mHorizontalFOV", pCamera->mHorizontalFOV);
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiMesh *pMesh) {
    // validate the material index of the mesh
    if (mScene->mNumMaterials && pMesh->mMaterialIndex >= mScene->mNumMaterials) {
        ReportError("aiMesh::mMaterialIndex is invalid (value: %i maximum: %i)",
                pMesh->mMaterialIndex, mScene->mNumMaterials - 1);
    }

    Validate(&pMesh->mName);

    for (unsigned int i = 0; i < pMesh->mNumFaces; ++i) {
        aiFace &face = pMesh->mFaces[i];

        if (pMesh->mPrimitiveTypes) {
            switch (face.mNumIndices) {
            case 0:
                ReportError("aiMesh::mFaces[%i].mNumIndices is 0", i);
                break;
            case 1:
                if (0 == (pMesh->mPrimitiveTypes & aiPrimitiveType_POINT)) {
                    ReportError("aiMesh::mFaces[%i] is a POINT but aiMesh::mPrimitiveTypes "
                                "does not report the POINT flag",
                            i);
                }
                break;
            case 2:
                if (0 == (pMesh->mPrimitiveTypes & aiPrimitiveType_LINE)) {
                    ReportError("aiMesh::mFaces[%i] is a LINE but aiMesh::mPrimitiveTypes "
                                "does not report the LINE flag",
                            i);
                }
                break;
            case 3:
                if (0 == (pMesh->mPrimitiveTypes & aiPrimitiveType_TRIANGLE)) {
                    ReportError("aiMesh::mFaces[%i] is a TRIANGLE but aiMesh::mPrimitiveTypes "
                                "does not report the TRIANGLE flag",
                            i);
                }
                break;
            default:
                if (0 == (pMesh->mPrimitiveTypes & aiPrimitiveType_POLYGON)) {
                    this->ReportError("aiMesh::mFaces[%i] is a POLYGON but aiMesh::mPrimitiveTypes "
                                      "does not report the POLYGON flag",
                            i);
                }
                break;
            };
        }

        if (!face.mIndices)
            ReportError("aiMesh::mFaces[%i].mIndices is nullptr", i);
    }

    // positions must always be there ...
    if (!pMesh->mNumVertices || (!pMesh->mVertices && !mScene->mFlags)) {
        ReportError("The mesh %s contains no vertices", pMesh->mName.C_Str());
    }

    if (pMesh->mNumVertices > AI_MAX_VERTICES) {
        ReportError("Mesh has too many vertices: %u, but the limit is %u", pMesh->mNumVertices, AI_MAX_VERTICES);
    }
    if (pMesh->mNumFaces > AI_MAX_FACES) {
        ReportError("Mesh has too many faces: %u, but the limit is %u", pMesh->mNumFaces, AI_MAX_FACES);
    }

    // if tangents are there there must also be bitangent vectors ...
    if ((pMesh->mTangents != nullptr) != (pMesh->mBitangents != nullptr)) {
        ReportError("If there are tangents, bitangent vectors must be present as well");
    }

    // faces, too
    if (!pMesh->mNumFaces || (!pMesh->mFaces && !mScene->mFlags)) {
        ReportError("Mesh %s contains no faces", pMesh->mName.C_Str());
    }

    // now check whether the face indexing layout is correct:
    // unique vertices, pseudo-indexed.
    std::vector<bool> abRefList;
    abRefList.resize(pMesh->mNumVertices, false);
    for (unsigned int i = 0; i < pMesh->mNumFaces; ++i) {
        aiFace &face = pMesh->mFaces[i];
        if (face.mNumIndices > AI_MAX_FACE_INDICES) {
            ReportError("Face %u has too many faces: %u, but the limit is %u", i, face.mNumIndices, AI_MAX_FACE_INDICES);
        }

        for (unsigned int a = 0; a < face.mNumIndices; ++a) {
            if (face.mIndices[a] >= pMesh->mNumVertices) {
                ReportError("aiMesh::mFaces[%i]::mIndices[%i] is out of range", i, a);
            }
            // the MSB flag is temporarily used by the extra verbose
            // mode to tell us that the JoinVerticesProcess might have
            // been executed already.
            /*if ( !(this->mScene->mFlags & AI_SCENE_FLAGS_NON_VERBOSE_FORMAT ) && !(this->mScene->mFlags & AI_SCENE_FLAGS_ALLOW_SHARED) &&
				abRefList[face.mIndices[a]])
            {
                ReportError("aiMesh::mVertices[%i] is referenced twice - second "
                    "time by aiMesh::mFaces[%i]::mIndices[%i]",face.mIndices[a],i,a);
            }*/
            abRefList[face.mIndices[a]] = true;
        }
    }

    // check whether there are vertices that aren't referenced by a face
    bool b = false;
    for (unsigned int i = 0; i < pMesh->mNumVertices; ++i) {
        if (!abRefList[i]) b = true;
    }
    abRefList.clear();
    if (b) {
        ReportWarning("There are unreferenced vertices");
    }

    // texture channel 2 may not be set if channel 1 is zero ...
    {
        unsigned int i = 0;
        for (; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
            if (!pMesh->HasTextureCoords(i)) break;
        }
        for (; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i)
            if (pMesh->HasTextureCoords(i)) {
                ReportError("Texture coordinate channel %i exists "
                            "although the previous channel was nullptr.",
                        i);
            }
    }
    // the same for the vertex colors
    {
        unsigned int i = 0;
        for (; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i) {
            if (!pMesh->HasVertexColors(i)) break;
        }
        for (; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i)
            if (pMesh->HasVertexColors(i)) {
                ReportError("Vertex color channel %i is exists "
                            "although the previous channel was nullptr.",
                        i);
            }
    }

    // now validate all bones
    if (pMesh->mNumBones) {
        if (!pMesh->mBones) {
            ReportError("aiMesh::mBones is nullptr (aiMesh::mNumBones is %i)",
                    pMesh->mNumBones);
        }
        std::unique_ptr<float[]> afSum(nullptr);
        if (pMesh->mNumVertices) {
            afSum.reset(new float[pMesh->mNumVertices]);
            for (unsigned int i = 0; i < pMesh->mNumVertices; ++i)
                afSum[i] = 0.0f;
        }

        // check whether there are duplicate bone names
        for (unsigned int i = 0; i < pMesh->mNumBones; ++i) {
            const aiBone *bone = pMesh->mBones[i];
            if (bone->mNumWeights > AI_MAX_BONE_WEIGHTS) {
                ReportError("Bone %u has too many weights: %u, but the limit is %u", i, bone->mNumWeights, AI_MAX_BONE_WEIGHTS);
            }

            if (!pMesh->mBones[i]) {
                ReportError("aiMesh::mBones[%i] is nullptr (aiMesh::mNumBones is %i)",
                        i, pMesh->mNumBones);
            }
            Validate(pMesh, pMesh->mBones[i], afSum.get());

            for (unsigned int a = i + 1; a < pMesh->mNumBones; ++a) {
                if (pMesh->mBones[i]->mName == pMesh->mBones[a]->mName) {
                    const char *name = "unknown";
                    if (nullptr != pMesh->mBones[i]->mName.C_Str()) {
                        name = pMesh->mBones[i]->mName.C_Str();
                    }
                    ReportError("aiMesh::mBones[%i], name = \"%s\" has the same name as "
                                "aiMesh::mBones[%i]",
                            i, name, a);
                }
            }
        }
        // check whether all bone weights for a vertex sum to 1.0 ...
        for (unsigned int i = 0; i < pMesh->mNumVertices; ++i) {
            if (afSum[i] && (afSum[i] <= 0.94 || afSum[i] >= 1.05)) {
                ReportWarning("aiMesh::mVertices[%i]: bone weight sum != 1.0 (sum is %f)", i, afSum[i]);
            }
        }
    } else if (pMesh->mBones) {
        ReportError("aiMesh::mBones is non-null although there are no bones");
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiMesh *pMesh, const aiBone *pBone, float *afSum) {
    this->Validate(&pBone->mName);

    if (!pBone->mNumWeights) {
        //ReportError("aiBone::mNumWeights is zero");
    }

    // check whether all vertices affected by this bone are valid
    for (unsigned int i = 0; i < pBone->mNumWeights; ++i) {
        if (pBone->mWeights[i].mVertexId >= pMesh->mNumVertices) {
            ReportError("aiBone::mWeights[%i].mVertexId is out of range", i);
        } else if (!pBone->mWeights[i].mWeight || pBone->mWeights[i].mWeight > 1.0f) {
            ReportWarning("aiBone::mWeights[%i].mWeight has an invalid value", i);
        }
        afSum[pBone->mWeights[i].mVertexId] += pBone->mWeights[i].mWeight;
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiAnimation *pAnimation) {
    Validate(&pAnimation->mName);

    // validate all animations
    if (pAnimation->mNumChannels || pAnimation->mNumMorphMeshChannels) {
        if (!pAnimation->mChannels && pAnimation->mNumChannels) {
            ReportError("aiAnimation::mChannels is nullptr (aiAnimation::mNumChannels is %i)",
                    pAnimation->mNumChannels);
        }
        if (!pAnimation->mMorphMeshChannels && pAnimation->mNumMorphMeshChannels) {
            ReportError("aiAnimation::mMorphMeshChannels is nullptr (aiAnimation::mNumMorphMeshChannels is %i)",
                    pAnimation->mNumMorphMeshChannels);
        }
        for (unsigned int i = 0; i < pAnimation->mNumChannels; ++i) {
            if (!pAnimation->mChannels[i]) {
                ReportError("aiAnimation::mChannels[%i] is nullptr (aiAnimation::mNumChannels is %i)",
                        i, pAnimation->mNumChannels);
            }
            Validate(pAnimation, pAnimation->mChannels[i]);
        }
        for (unsigned int i = 0; i < pAnimation->mNumMorphMeshChannels; ++i) {
            if (!pAnimation->mMorphMeshChannels[i]) {
                ReportError("aiAnimation::mMorphMeshChannels[%i] is nullptr (aiAnimation::mNumMorphMeshChannels is %i)",
                        i, pAnimation->mNumMorphMeshChannels);
            }
            Validate(pAnimation, pAnimation->mMorphMeshChannels[i]);
        }
    } else {
        ReportError("aiAnimation::mNumChannels is 0. At least one node animation channel must be there.");
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::SearchForInvalidTextures(const aiMaterial *pMaterial,
        aiTextureType type) {
    const char *szType = TextureTypeToString(type);

    // ****************************************************************************
    // Search all keys of the material ...
    // textures must be specified with ascending indices
    // (e.g. diffuse #2 may not be specified if diffuse #1 is not there ...)
    // ****************************************************************************

    int iNumIndices = 0;
    int iIndex = -1;
    for (unsigned int i = 0; i < pMaterial->mNumProperties; ++i) {
        aiMaterialProperty *prop = pMaterial->mProperties[i];
        ai_assert(nullptr != prop);
        if (!::strcmp(prop->mKey.data, "$tex.file") && prop->mSemantic == static_cast<unsigned int>(type)) {
            iIndex = std::max(iIndex, (int)prop->mIndex);
            ++iNumIndices;

            if (aiPTI_String != prop->mType) {
                ReportError("Material property %s is expected to be a string", prop->mKey.data);
            }
        }
    }
    if (iIndex + 1 != iNumIndices) {
        ReportError("%s #%i is set, but there are only %i %s textures",
                szType, iIndex, iNumIndices, szType);
    }
    if (!iNumIndices) {
        return;
    }
    std::vector<aiTextureMapping> mappings(iNumIndices);

    // Now check whether all UV indices are valid ...
    bool bNoSpecified = true;
    for (unsigned int i = 0; i < pMaterial->mNumProperties; ++i) {
        aiMaterialProperty *prop = pMaterial->mProperties[i];
        if (static_cast<aiTextureType>(prop->mSemantic) != type) {
            continue;
        }

        if ((int)prop->mIndex >= iNumIndices) {
            ReportError("Found texture property with index %i, although there "
                        "are only %i textures of type %s",
                    prop->mIndex, iNumIndices, szType);
        }

        if (!::strcmp(prop->mKey.data, "$tex.mapping")) {
            if (aiPTI_Integer != prop->mType || prop->mDataLength < sizeof(aiTextureMapping)) {
                ReportError("Material property %s%i is expected to be an integer (size is %i)",
                        prop->mKey.data, prop->mIndex, prop->mDataLength);
            }
            mappings[prop->mIndex] = *((aiTextureMapping *)prop->mData);
        } else if (!::strcmp(prop->mKey.data, "$tex.uvtrafo")) {
            if (aiPTI_Float != prop->mType || prop->mDataLength < sizeof(aiUVTransform)) {
                ReportError("Material property %s%i is expected to be 5 floats large (size is %i)",
                        prop->mKey.data, prop->mIndex, prop->mDataLength);
            }
            //mappings[prop->mIndex] = ((aiUVTransform*)prop->mData);
        } else if (!::strcmp(prop->mKey.data, "$tex.uvwsrc")) {
            if (aiPTI_Integer != prop->mType || sizeof(int) > prop->mDataLength) {
                ReportError("Material property %s%i is expected to be an integer (size is %i)",
                        prop->mKey.data, prop->mIndex, prop->mDataLength);
            }
            bNoSpecified = false;

            // Ignore UV indices for texture channels that are not there ...

            // Get the value
            iIndex = *((unsigned int *)prop->mData);

            // Check whether there is a mesh using this material
            // which has not enough UV channels ...
            for (unsigned int a = 0; a < mScene->mNumMeshes; ++a) {
                aiMesh *mesh = this->mScene->mMeshes[a];
                if (mesh->mMaterialIndex == (unsigned int)i) {
                    int iChannels = 0;
                    while (mesh->HasTextureCoords(iChannels))
                        ++iChannels;
                    if (iIndex >= iChannels) {
                        ReportWarning("Invalid UV index: %i (key %s). Mesh %i has only %i UV channels",
                                iIndex, prop->mKey.data, a, iChannels);
                    }
                }
            }
        }
    }
    if (bNoSpecified) {
        // Assume that all textures are using the first UV channel
        for (unsigned int a = 0; a < mScene->mNumMeshes; ++a) {
            aiMesh *mesh = mScene->mMeshes[a];
            if (mesh->mMaterialIndex == (unsigned int)iIndex && mappings[0] == aiTextureMapping_UV) {
                if (!mesh->mTextureCoords[0]) {
                    // This is a special case ... it could be that the
                    // original mesh format intended the use of a special
                    // mapping here.
                    ReportWarning("UV-mapped texture, but there are no UV coords");
                }
            }
        }
    }
}
// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiMaterial *pMaterial) {
    // check whether there are material keys that are obviously not legal
    for (unsigned int i = 0; i < pMaterial->mNumProperties; ++i) {
        const aiMaterialProperty *prop = pMaterial->mProperties[i];
        if (!prop) {
            ReportError("aiMaterial::mProperties[%i] is nullptr (aiMaterial::mNumProperties is %i)",
                    i, pMaterial->mNumProperties);
        }
        if (!prop->mDataLength || !prop->mData) {
            ReportError("aiMaterial::mProperties[%i].mDataLength or "
                        "aiMaterial::mProperties[%i].mData is 0",
                    i, i);
        }
        // check all predefined types
        if (aiPTI_String == prop->mType) {
            // FIX: strings are now stored in a less expensive way, but we can't use the
            // validation routine for 'normal' aiStrings
            if (prop->mDataLength < 5 || prop->mDataLength < 4 + (*reinterpret_cast<uint32_t *>(prop->mData)) + 1) {
                ReportError("aiMaterial::mProperties[%i].mDataLength is "
                            "too small to contain a string (%i, needed: %i)",
                        i, prop->mDataLength, static_cast<int>(sizeof(aiString)));
            }
            if (prop->mData[prop->mDataLength - 1]) {
                ReportError("Missing null-terminator in string material property");
            }
            //  Validate((const aiString*)prop->mData);
        } else if (aiPTI_Float == prop->mType) {
            if (prop->mDataLength < sizeof(float)) {
                ReportError("aiMaterial::mProperties[%i].mDataLength is "
                            "too small to contain a float (%i, needed: %i)",
                        i, prop->mDataLength, static_cast<int>(sizeof(float)));
            }
        } else if (aiPTI_Integer == prop->mType) {
            if (prop->mDataLength < sizeof(int)) {
                ReportError("aiMaterial::mProperties[%i].mDataLength is "
                            "too small to contain an integer (%i, needed: %i)",
                        i, prop->mDataLength, static_cast<int>(sizeof(int)));
            }
        }
        // TODO: check whether there is a key with an unknown name ...
    }

    // make some more specific tests
    ai_real fTemp;
    int iShading;
    if (AI_SUCCESS == aiGetMaterialInteger(pMaterial, AI_MATKEY_SHADING_MODEL, &iShading)) {
        switch ((aiShadingMode)iShading) {
        case aiShadingMode_Blinn:
        case aiShadingMode_CookTorrance:
        case aiShadingMode_Phong:

            if (AI_SUCCESS != aiGetMaterialFloat(pMaterial, AI_MATKEY_SHININESS, &fTemp)) {
                ReportWarning("A specular shading model is specified but there is no "
                              "AI_MATKEY_SHININESS key");
            }
            if (AI_SUCCESS == aiGetMaterialFloat(pMaterial, AI_MATKEY_SHININESS_STRENGTH, &fTemp) && !fTemp) {
                ReportWarning("A specular shading model is specified but the value of the "
                              "AI_MATKEY_SHININESS_STRENGTH key is 0.0");
            }
            break;
        default:
            break;
        }
    }

    if (AI_SUCCESS == aiGetMaterialFloat(pMaterial, AI_MATKEY_OPACITY, &fTemp) && (!fTemp || fTemp > 1.01)) {
        ReportWarning("Invalid opacity value (must be 0 < opacity < 1.0)");
    }

    // Check whether there are invalid texture keys
    // TODO: that's a relict of the past, where texture type and index were baked
    // into the material string ... we could do that in one single pass.
    SearchForInvalidTextures(pMaterial, aiTextureType_DIFFUSE);
    SearchForInvalidTextures(pMaterial, aiTextureType_SPECULAR);
    SearchForInvalidTextures(pMaterial, aiTextureType_AMBIENT);
    SearchForInvalidTextures(pMaterial, aiTextureType_EMISSIVE);
    SearchForInvalidTextures(pMaterial, aiTextureType_OPACITY);
    SearchForInvalidTextures(pMaterial, aiTextureType_SHININESS);
    SearchForInvalidTextures(pMaterial, aiTextureType_HEIGHT);
    SearchForInvalidTextures(pMaterial, aiTextureType_NORMALS);
    SearchForInvalidTextures(pMaterial, aiTextureType_DISPLACEMENT);
    SearchForInvalidTextures(pMaterial, aiTextureType_LIGHTMAP);
    SearchForInvalidTextures(pMaterial, aiTextureType_REFLECTION);
    SearchForInvalidTextures(pMaterial, aiTextureType_BASE_COLOR);
    SearchForInvalidTextures(pMaterial, aiTextureType_NORMAL_CAMERA);
    SearchForInvalidTextures(pMaterial, aiTextureType_EMISSION_COLOR);
    SearchForInvalidTextures(pMaterial, aiTextureType_METALNESS);
    SearchForInvalidTextures(pMaterial, aiTextureType_DIFFUSE_ROUGHNESS);
    SearchForInvalidTextures(pMaterial, aiTextureType_AMBIENT_OCCLUSION);
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiTexture *pTexture) {
    // the data section may NEVER be nullptr
    if (nullptr == pTexture->pcData) {
        ReportError("aiTexture::pcData is nullptr");
    }
    if (pTexture->mHeight) {
        if (!pTexture->mWidth) {
            ReportError("aiTexture::mWidth is zero (aiTexture::mHeight is %i, uncompressed texture)",
                    pTexture->mHeight);
        }
    } else {
        if (!pTexture->mWidth) {
            ReportError("aiTexture::mWidth is zero (compressed texture)");
        }
        if ('\0' != pTexture->achFormatHint[HINTMAXTEXTURELEN - 1]) {
            ReportWarning("aiTexture::achFormatHint must be zero-terminated");
        } else if ('.' == pTexture->achFormatHint[0]) {
            ReportWarning("aiTexture::achFormatHint should contain a file extension "
                          "without a leading dot (format hint: %s).",
                    pTexture->achFormatHint);
        }
    }

    const char *sz = pTexture->achFormatHint;
    if ((sz[0] >= 'A' && sz[0] <= 'Z') ||
            (sz[1] >= 'A' && sz[1] <= 'Z') ||
            (sz[2] >= 'A' && sz[2] <= 'Z') ||
            (sz[3] >= 'A' && sz[3] <= 'Z')) {
        ReportError("aiTexture::achFormatHint contains non-lowercase letters");
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiAnimation *pAnimation,
        const aiNodeAnim *pNodeAnim) {
    Validate(&pNodeAnim->mNodeName);

    if (!pNodeAnim->mNumPositionKeys && !pNodeAnim->mScalingKeys && !pNodeAnim->mNumRotationKeys) {
        ReportError("Empty node animation channel");
    }
    // otherwise check whether one of the keys exceeds the total duration of the animation
    if (pNodeAnim->mNumPositionKeys) {
        if (!pNodeAnim->mPositionKeys) {
            ReportError("aiNodeAnim::mPositionKeys is nullptr (aiNodeAnim::mNumPositionKeys is %i)",
                    pNodeAnim->mNumPositionKeys);
        }
        double dLast = -10e10;
        for (unsigned int i = 0; i < pNodeAnim->mNumPositionKeys; ++i) {
            // ScenePreprocessor will compute the duration if still the default value
            // (Aramis) Add small epsilon, comparison tended to fail if max_time == duration,
            //  seems to be due the compilers register usage/width.
            if (pAnimation->mDuration > 0. && pNodeAnim->mPositionKeys[i].mTime > pAnimation->mDuration + 0.001) {
                ReportError("aiNodeAnim::mPositionKeys[%i].mTime (%.5f) is larger "
                            "than aiAnimation::mDuration (which is %.5f)",
                        i,
                        (float)pNodeAnim->mPositionKeys[i].mTime,
                        (float)pAnimation->mDuration);
            }
            if (i && pNodeAnim->mPositionKeys[i].mTime <= dLast) {
                ReportWarning("aiNodeAnim::mPositionKeys[%i].mTime (%.5f) is smaller "
                              "than aiAnimation::mPositionKeys[%i] (which is %.5f)",
                        i,
                        (float)pNodeAnim->mPositionKeys[i].mTime,
                        i - 1, (float)dLast);
            }
            dLast = pNodeAnim->mPositionKeys[i].mTime;
        }
    }
    // rotation keys
    if (pNodeAnim->mNumRotationKeys) {
        if (!pNodeAnim->mRotationKeys) {
            ReportError("aiNodeAnim::mRotationKeys is nullptr (aiNodeAnim::mNumRotationKeys is %i)",
                    pNodeAnim->mNumRotationKeys);
        }
        double dLast = -10e10;
        for (unsigned int i = 0; i < pNodeAnim->mNumRotationKeys; ++i) {
            if (pAnimation->mDuration > 0. && pNodeAnim->mRotationKeys[i].mTime > pAnimation->mDuration + 0.001) {
                ReportError("aiNodeAnim::mRotationKeys[%i].mTime (%.5f) is larger "
                            "than aiAnimation::mDuration (which is %.5f)",
                        i,
                        (float)pNodeAnim->mRotationKeys[i].mTime,
                        (float)pAnimation->mDuration);
            }
            if (i && pNodeAnim->mRotationKeys[i].mTime <= dLast) {
                ReportWarning("aiNodeAnim::mRotationKeys[%i].mTime (%.5f) is smaller "
                              "than aiAnimation::mRotationKeys[%i] (which is %.5f)",
                        i,
                        (float)pNodeAnim->mRotationKeys[i].mTime,
                        i - 1, (float)dLast);
            }
            dLast = pNodeAnim->mRotationKeys[i].mTime;
        }
    }
    // scaling keys
    if (pNodeAnim->mNumScalingKeys) {
        if (!pNodeAnim->mScalingKeys) {
            ReportError("aiNodeAnim::mScalingKeys is nullptr (aiNodeAnim::mNumScalingKeys is %i)",
                    pNodeAnim->mNumScalingKeys);
        }
        double dLast = -10e10;
        for (unsigned int i = 0; i < pNodeAnim->mNumScalingKeys; ++i) {
            if (pAnimation->mDuration > 0. && pNodeAnim->mScalingKeys[i].mTime > pAnimation->mDuration + 0.001) {
                ReportError("aiNodeAnim::mScalingKeys[%i].mTime (%.5f) is larger "
                            "than aiAnimation::mDuration (which is %.5f)",
                        i,
                        (float)pNodeAnim->mScalingKeys[i].mTime,
                        (float)pAnimation->mDuration);
            }
            if (i && pNodeAnim->mScalingKeys[i].mTime <= dLast) {
                ReportWarning("aiNodeAnim::mScalingKeys[%i].mTime (%.5f) is smaller "
                              "than aiAnimation::mScalingKeys[%i] (which is %.5f)",
                        i,
                        (float)pNodeAnim->mScalingKeys[i].mTime,
                        i - 1, (float)dLast);
            }
            dLast = pNodeAnim->mScalingKeys[i].mTime;
        }
    }

    if (!pNodeAnim->mNumScalingKeys && !pNodeAnim->mNumRotationKeys &&
            !pNodeAnim->mNumPositionKeys) {
        ReportError("A node animation channel must have at least one subtrack");
    }
}

void ValidateDSProcess::Validate(const aiAnimation *pAnimation,
        const aiMeshMorphAnim *pMeshMorphAnim) {
    Validate(&pMeshMorphAnim->mName);

    if (!pMeshMorphAnim->mNumKeys) {
        ReportError("Empty mesh morph animation channel");
    }

    // otherwise check whether one of the keys exceeds the total duration of the animation
    if (pMeshMorphAnim->mNumKeys) {
        if (!pMeshMorphAnim->mKeys) {
            ReportError("aiMeshMorphAnim::mKeys is nullptr (aiMeshMorphAnim::mNumKeys is %i)",
                    pMeshMorphAnim->mNumKeys);
        }
        double dLast = -10e10;
        for (unsigned int i = 0; i < pMeshMorphAnim->mNumKeys; ++i) {
            // ScenePreprocessor will compute the duration if still the default value
            // (Aramis) Add small epsilon, comparison tended to fail if max_time == duration,
            //  seems to be due the compilers register usage/width.
            if (pAnimation->mDuration > 0. && pMeshMorphAnim->mKeys[i].mTime > pAnimation->mDuration + 0.001) {
                ReportError("aiMeshMorphAnim::mKeys[%i].mTime (%.5f) is larger "
                            "than aiAnimation::mDuration (which is %.5f)",
                        i,
                        (float)pMeshMorphAnim->mKeys[i].mTime,
                        (float)pAnimation->mDuration);
            }
            if (i && pMeshMorphAnim->mKeys[i].mTime <= dLast) {
                ReportWarning("aiMeshMorphAnim::mKeys[%i].mTime (%.5f) is smaller "
                              "than aiMeshMorphAnim::mKeys[%i] (which is %.5f)",
                        i,
                        (float)pMeshMorphAnim->mKeys[i].mTime,
                        i - 1, (float)dLast);
            }
            dLast = pMeshMorphAnim->mKeys[i].mTime;
        }
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiNode *pNode) {
    if (!pNode) {
        ReportError("A node of the scene-graph is nullptr");
    }
    // Validate node name string first so that it's safe to use in below expressions
    this->Validate(&pNode->mName);
    const char *nodeName = (&pNode->mName)->C_Str();
    if (pNode != mScene->mRootNode && !pNode->mParent) {
        ReportError("Non-root node %s lacks a valid parent (aiNode::mParent is nullptr) ", nodeName);
    }

    // validate all meshes
    if (pNode->mNumMeshes) {
        if (!pNode->mMeshes) {
            ReportError("aiNode::mMeshes is nullptr for node %s (aiNode::mNumMeshes is %i)",
                    nodeName, pNode->mNumMeshes);
        }
        std::vector<bool> abHadMesh;
        abHadMesh.resize(mScene->mNumMeshes, false);
        for (unsigned int i = 0; i < pNode->mNumMeshes; ++i) {
            if (pNode->mMeshes[i] >= mScene->mNumMeshes) {
                ReportError("aiNode::mMeshes[%i] is out of range for node %s (maximum is %i)",
                        pNode->mMeshes[i], nodeName, mScene->mNumMeshes - 1);
            }
            if (abHadMesh[pNode->mMeshes[i]]) {
                ReportError("aiNode::mMeshes[%i] is already referenced by this node %s (value: %i)",
                        i, nodeName, pNode->mMeshes[i]);
            }
            abHadMesh[pNode->mMeshes[i]] = true;
        }
    }
    if (pNode->mNumChildren) {
        if (!pNode->mChildren) {
            ReportError("aiNode::mChildren is nullptr for node %s (aiNode::mNumChildren is %i)",
                    nodeName, pNode->mNumChildren);
        }
        for (unsigned int i = 0; i < pNode->mNumChildren; ++i) {
            Validate(pNode->mChildren[i]);
        }
    }
}

// ------------------------------------------------------------------------------------------------
void ValidateDSProcess::Validate(const aiString *pString) {
    if (pString->length > MAXLEN) {
        ReportError("aiString::length is too large (%u, maximum is %lu)",
                pString->length, MAXLEN);
    }
    const char *sz = pString->data;
    while (true) {
        if ('\0' == *sz) {
            if (pString->length != (unsigned int)(sz - pString->data)) {
                ReportError("aiString::data is invalid: the terminal zero is at a wrong offset");
            }
            break;
        } else if (sz >= &pString->data[MAXLEN]) {
            ReportError("aiString::data is invalid. There is no terminal character");
        }
        ++sz;
    }
}
