Function GetMeshHash

code/PostProcessing/FindInstancesProcess.h:63–74

------------------------------------------------------------------------------- @brief Get a pseudo(!)-hash representing a mesh. * * The hash is built from number of vertices, faces, primitive types, * .... but *not* from the real mesh data. The funcction is not a perfect hash. * @param in Input mesh * @return Hash. */

 *  @return Hash.
 */
inline uint64_t GetMeshHash(aiMesh* in) {
    ai_assert(nullptr != in);

    // ... get an unique value representing the vertex format of the mesh
    const unsigned int fhash = GetMeshVFormatUnique(in);

    // and bake it with number of vertices/faces/bones/matidx/ptypes
    return ((uint64_t)fhash << 32u) | ((
        (in->mNumBones << 16u) ^  (in->mNumVertices)       ^
        (in->mNumFaces<<4u)    ^  (in->mMaterialIndex<<15) ^
        (in->mPrimitiveTypes<<28)) & 0xffffffff );
}

// -------------------------------------------------------------------------------
/** @brief Perform a component-wise comparison of two arrays