Add Assimp library in thirdparty

From https://github.com/assimp/assimp repo at d2b45377e4b09a1f43be95e45553afcc06b03f4b
2025-11-09 12:50:35 +00:00 · 2019-04-02 22:54:58 -07:00
parent a61ad365f5
commit 793b0de197
236 changed files with 72097 additions and 0 deletions
--- a/thirdparty/assimp/code/FBXDocument.cpp
+++ b/thirdparty/assimp/code/FBXDocument.cpp
@@ -0,0 +1,726 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the*
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXDocument.cpp
+ *  @brief Implementation of the FBX DOM classes
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXDocument.h"
+#include "FBXMeshGeometry.h"
+#include "FBXParser.h"
+#include "FBXUtil.h"
+#include "FBXImporter.h"
+#include "FBXImportSettings.h"
+#include "FBXDocumentUtil.h"
+#include "FBXProperties.h"
+
+#include <memory>
+#include <functional>
+#include <map>
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+LazyObject::LazyObject(uint64_t id, const Element& element, const Document& doc)
+: doc(doc)
+, element(element)
+, id(id)
+, flags() {
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject::~LazyObject()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+const Object* LazyObject::Get(bool dieOnError)
+{
+    if(IsBeingConstructed() || FailedToConstruct()) {
+        return nullptr;
+    }
+
+    if (object.get()) {
+        return object.get();
+    }
+
+    // if this is the root object, we return a dummy since there
+    // is no root object int he fbx file - it is just referenced
+    // with id 0.
+    if(id == 0L) {
+        object.reset(new Object(id, element, "Model::RootNode"));
+        return object.get();
+    }
+
+    const Token& key = element.KeyToken();
+    const TokenList& tokens = element.Tokens();
+
+    if(tokens.size() < 3) {
+        DOMError("expected at least 3 tokens: id, name and class tag",&element);
+    }
+
+    const char* err;
+    std::string name = ParseTokenAsString(*tokens[1],err);
+    if (err) {
+        DOMError(err,&element);
+    }
+
+    // small fix for binary reading: binary fbx files don't use
+    // prefixes such as Model:: in front of their names. The
+    // loading code expects this at many places, though!
+    // so convert the binary representation (a 0x0001) to the
+    // double colon notation.
+    if(tokens[1]->IsBinary()) {
+        for (size_t i = 0; i < name.length(); ++i) {
+            if (name[i] == 0x0 && name[i+1] == 0x1) {
+                name = name.substr(i+2) + "::" + name.substr(0,i);
+            }
+        }
+    }
+
+    const std::string classtag = ParseTokenAsString(*tokens[2],err);
+    if (err) {
+        DOMError(err,&element);
+    }
+
+    // prevent recursive calls
+    flags |= BEING_CONSTRUCTED;
+
+    try {
+        // this needs to be relatively fast since it happens a lot,
+        // so avoid constructing strings all the time.
+        const char* obtype = key.begin();
+        const size_t length = static_cast<size_t>(key.end()-key.begin());
+
+        // For debugging
+        //dumpObjectClassInfo( objtype, classtag );
+
+        if (!strncmp(obtype,"Geometry",length)) {
+            if (!strcmp(classtag.c_str(),"Mesh")) {
+                object.reset(new MeshGeometry(id,element,name,doc));
+            }
+            if (!strcmp(classtag.c_str(), "Shape")) {
+                object.reset(new ShapeGeometry(id, element, name, doc));
+            }
+            if (!strcmp(classtag.c_str(), "Line")) {
+                object.reset(new LineGeometry(id, element, name, doc));
+            }
+        }
+        else if (!strncmp(obtype,"NodeAttribute",length)) {
+            if (!strcmp(classtag.c_str(),"Camera")) {
+                object.reset(new Camera(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"CameraSwitcher")) {
+                object.reset(new CameraSwitcher(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"Light")) {
+                object.reset(new Light(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"Null")) {
+                object.reset(new Null(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"LimbNode")) {
+                object.reset(new LimbNode(id,element,doc,name));
+            }
+        }
+        else if (!strncmp(obtype,"Deformer",length)) {
+            if (!strcmp(classtag.c_str(),"Cluster")) {
+                object.reset(new Cluster(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"Skin")) {
+                object.reset(new Skin(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(), "BlendShape")) {
+                object.reset(new BlendShape(id, element, doc, name));
+            }
+            else if (!strcmp(classtag.c_str(), "BlendShapeChannel")) {
+                object.reset(new BlendShapeChannel(id, element, doc, name));
+            }
+        }
+        else if ( !strncmp( obtype, "Model", length ) ) {
+            // FK and IK effectors are not supported
+            if ( strcmp( classtag.c_str(), "IKEffector" ) && strcmp( classtag.c_str(), "FKEffector" ) ) {
+                object.reset( new Model( id, element, doc, name ) );
+            }
+        }
+        else if (!strncmp(obtype,"Material",length)) {
+            object.reset(new Material(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"Texture",length)) {
+            object.reset(new Texture(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"LayeredTexture",length)) {
+            object.reset(new LayeredTexture(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"Video",length)) {
+            object.reset(new Video(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"AnimationStack",length)) {
+            object.reset(new AnimationStack(id,element,name,doc));
+        }
+        else if (!strncmp(obtype,"AnimationLayer",length)) {
+            object.reset(new AnimationLayer(id,element,name,doc));
+        }
+        // note: order matters for these two
+        else if (!strncmp(obtype,"AnimationCurve",length)) {
+            object.reset(new AnimationCurve(id,element,name,doc));
+        }
+        else if (!strncmp(obtype,"AnimationCurveNode",length)) {
+            object.reset(new AnimationCurveNode(id,element,name,doc));
+        }
+    }
+    catch(std::exception& ex) {
+        flags &= ~BEING_CONSTRUCTED;
+        flags |= FAILED_TO_CONSTRUCT;
+
+        if(dieOnError || doc.Settings().strictMode) {
+            throw;
+        }
+
+        // note: the error message is already formatted, so raw logging is ok
+        if(!DefaultLogger::isNullLogger()) {
+            ASSIMP_LOG_ERROR(ex.what());
+        }
+        return NULL;
+    }
+
+    if (!object.get()) {
+        //DOMError("failed to convert element to DOM object, class: " + classtag + ", name: " + name,&element);
+    }
+
+    flags &= ~BEING_CONSTRUCTED;
+    return object.get();
+}
+
+// ------------------------------------------------------------------------------------------------
+Object::Object(uint64_t id, const Element& element, const std::string& name)
+: element(element)
+, name(name)
+, id(id)
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Object::~Object()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+FileGlobalSettings::FileGlobalSettings(const Document& doc, std::shared_ptr<const PropertyTable> props)
+: props(props)
+, doc(doc)
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+FileGlobalSettings::~FileGlobalSettings()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Document::Document(const Parser& parser, const ImportSettings& settings)
+: settings(settings)
+, parser(parser)
+{
+    // Cannot use array default initialization syntax because vc8 fails on it
+    for (auto &timeStamp : creationTimeStamp) {
+        timeStamp = 0;
+    }
+
+    ReadHeader();
+    ReadPropertyTemplates();
+
+    ReadGlobalSettings();
+
+    // This order is important, connections need parsed objects to check
+    // whether connections are ok or not. Objects may not be evaluated yet,
+    // though, since this may require valid connections.
+    ReadObjects();
+    ReadConnections();
+}
+
+// ------------------------------------------------------------------------------------------------
+Document::~Document()
+{
+    for(ObjectMap::value_type& v : objects) {
+        delete v.second;
+    }
+
+    for(ConnectionMap::value_type& v : src_connections) {
+        delete v.second;
+    }
+    // |dest_connections| contain the same Connection objects as the |src_connections|
+}
+
+// ------------------------------------------------------------------------------------------------
+static const unsigned int LowerSupportedVersion = 7100;
+static const unsigned int UpperSupportedVersion = 7400;
+
+void Document::ReadHeader() {
+    // Read ID objects from "Objects" section
+    const Scope& sc = parser.GetRootScope();
+    const Element* const ehead = sc["FBXHeaderExtension"];
+    if(!ehead || !ehead->Compound()) {
+        DOMError("no FBXHeaderExtension dictionary found");
+    }
+
+    const Scope& shead = *ehead->Compound();
+    fbxVersion = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(shead,"FBXVersion",ehead),0));
+
+    // While we may have some success with newer files, we don't support
+    // the older 6.n fbx format
+    if(fbxVersion < LowerSupportedVersion ) {
+        DOMError("unsupported, old format version, supported are only FBX 2011, FBX 2012 and FBX 2013");
+    }
+    if(fbxVersion > UpperSupportedVersion ) {
+        if(Settings().strictMode) {
+            DOMError("unsupported, newer format version, supported are only FBX 2011, FBX 2012 and FBX 2013"
+                " (turn off strict mode to try anyhow) ");
+        }
+        else {
+            DOMWarning("unsupported, newer format version, supported are only FBX 2011, FBX 2012 and FBX 2013,"
+                " trying to read it nevertheless");
+        }
+    }
+
+    const Element* const ecreator = shead["Creator"];
+    if(ecreator) {
+        creator = ParseTokenAsString(GetRequiredToken(*ecreator,0));
+    }
+
+    const Element* const etimestamp = shead["CreationTimeStamp"];
+    if(etimestamp && etimestamp->Compound()) {
+        const Scope& stimestamp = *etimestamp->Compound();
+        creationTimeStamp[0] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Year"),0));
+        creationTimeStamp[1] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Month"),0));
+        creationTimeStamp[2] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Day"),0));
+        creationTimeStamp[3] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Hour"),0));
+        creationTimeStamp[4] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Minute"),0));
+        creationTimeStamp[5] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Second"),0));
+        creationTimeStamp[6] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Millisecond"),0));
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadGlobalSettings()
+{
+    const Scope& sc = parser.GetRootScope();
+    const Element* const ehead = sc["GlobalSettings"];
+    if ( nullptr == ehead || !ehead->Compound() ) {
+        DOMWarning( "no GlobalSettings dictionary found" );
+        globals.reset(new FileGlobalSettings(*this, std::make_shared<const PropertyTable>()));
+        return;
+    }
+
+    std::shared_ptr<const PropertyTable> props = GetPropertyTable( *this, "", *ehead, *ehead->Compound(), true );
+
+    //double v = PropertyGet<float>( *props.get(), std::string("UnitScaleFactor"), 1.0 );
+
+    if(!props) {
+        DOMError("GlobalSettings dictionary contains no property table");
+    }
+
+    globals.reset(new FileGlobalSettings(*this, props));
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadObjects()
+{
+    // read ID objects from "Objects" section
+    const Scope& sc = parser.GetRootScope();
+    const Element* const eobjects = sc["Objects"];
+    if(!eobjects || !eobjects->Compound()) {
+        DOMError("no Objects dictionary found");
+    }
+
+    // add a dummy entry to represent the Model::RootNode object (id 0),
+    // which is only indirectly defined in the input file
+    objects[0] = new LazyObject(0L, *eobjects, *this);
+
+    const Scope& sobjects = *eobjects->Compound();
+    for(const ElementMap::value_type& el : sobjects.Elements()) {
+
+        // extract ID
+        const TokenList& tok = el.second->Tokens();
+
+        if (tok.empty()) {
+            DOMError("expected ID after object key",el.second);
+        }
+
+        const char* err;
+        const uint64_t id = ParseTokenAsID(*tok[0], err);
+        if(err) {
+            DOMError(err,el.second);
+        }
+
+        // id=0 is normally implicit
+        if(id == 0L) {
+            DOMError("encountered object with implicitly defined id 0",el.second);
+        }
+
+        if(objects.find(id) != objects.end()) {
+            DOMWarning("encountered duplicate object id, ignoring first occurrence",el.second);
+        }
+
+        objects[id] = new LazyObject(id, *el.second, *this);
+
+        // grab all animation stacks upfront since there is no listing of them
+        if(!strcmp(el.first.c_str(),"AnimationStack")) {
+            animationStacks.push_back(id);
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadPropertyTemplates()
+{
+    const Scope& sc = parser.GetRootScope();
+    // read property templates from "Definitions" section
+    const Element* const edefs = sc["Definitions"];
+    if(!edefs || !edefs->Compound()) {
+        DOMWarning("no Definitions dictionary found");
+        return;
+    }
+
+    const Scope& sdefs = *edefs->Compound();
+    const ElementCollection otypes = sdefs.GetCollection("ObjectType");
+    for(ElementMap::const_iterator it = otypes.first; it != otypes.second; ++it) {
+        const Element& el = *(*it).second;
+        const Scope* sc = el.Compound();
+        if(!sc) {
+            DOMWarning("expected nested scope in ObjectType, ignoring",&el);
+            continue;
+        }
+
+        const TokenList& tok = el.Tokens();
+        if(tok.empty()) {
+            DOMWarning("expected name for ObjectType element, ignoring",&el);
+            continue;
+        }
+
+        const std::string& oname = ParseTokenAsString(*tok[0]);
+
+        const ElementCollection templs = sc->GetCollection("PropertyTemplate");
+        for(ElementMap::const_iterator it = templs.first; it != templs.second; ++it) {
+            const Element& el = *(*it).second;
+            const Scope* sc = el.Compound();
+            if(!sc) {
+                DOMWarning("expected nested scope in PropertyTemplate, ignoring",&el);
+                continue;
+            }
+
+            const TokenList& tok = el.Tokens();
+            if(tok.empty()) {
+                DOMWarning("expected name for PropertyTemplate element, ignoring",&el);
+                continue;
+            }
+
+            const std::string& pname = ParseTokenAsString(*tok[0]);
+
+            const Element* Properties70 = (*sc)["Properties70"];
+            if(Properties70) {
+                std::shared_ptr<const PropertyTable> props = std::make_shared<const PropertyTable>(
+                    *Properties70,std::shared_ptr<const PropertyTable>(static_cast<const PropertyTable*>(NULL))
+                );
+
+                templates[oname+"."+pname] = props;
+            }
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadConnections()
+{
+    const Scope& sc = parser.GetRootScope();
+    // read property templates from "Definitions" section
+    const Element* const econns = sc["Connections"];
+    if(!econns || !econns->Compound()) {
+        DOMError("no Connections dictionary found");
+    }
+
+    uint64_t insertionOrder = 0l;
+    const Scope& sconns = *econns->Compound();
+    const ElementCollection conns = sconns.GetCollection("C");
+    for(ElementMap::const_iterator it = conns.first; it != conns.second; ++it) {
+        const Element& el = *(*it).second;
+        const std::string& type = ParseTokenAsString(GetRequiredToken(el,0));
+
+        // PP = property-property connection, ignored for now
+        // (tokens: "PP", ID1, "Property1", ID2, "Property2")
+        if ( type == "PP" ) {
+            continue;
+        }
+
+        const uint64_t src = ParseTokenAsID(GetRequiredToken(el,1));
+        const uint64_t dest = ParseTokenAsID(GetRequiredToken(el,2));
+
+        // OO = object-object connection
+        // OP = object-property connection, in which case the destination property follows the object ID
+        const std::string& prop = (type == "OP" ? ParseTokenAsString(GetRequiredToken(el,3)) : "");
+
+        if(objects.find(src) == objects.end()) {
+            DOMWarning("source object for connection does not exist",&el);
+            continue;
+        }
+
+        // dest may be 0 (root node) but we added a dummy object before
+        if(objects.find(dest) == objects.end()) {
+            DOMWarning("destination object for connection does not exist",&el);
+            continue;
+        }
+
+        // add new connection
+        const Connection* const c = new Connection(insertionOrder++,src,dest,prop,*this);
+        src_connections.insert(ConnectionMap::value_type(src,c));
+        dest_connections.insert(ConnectionMap::value_type(dest,c));
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<const AnimationStack*>& Document::AnimationStacks() const
+{
+    if (!animationStacksResolved.empty() || animationStacks.empty()) {
+        return animationStacksResolved;
+    }
+
+    animationStacksResolved.reserve(animationStacks.size());
+    for(uint64_t id : animationStacks) {
+        LazyObject* const lazy = GetObject(id);
+        const AnimationStack* stack;
+        if(!lazy || !(stack = lazy->Get<AnimationStack>())) {
+            DOMWarning("failed to read AnimationStack object");
+            continue;
+        }
+        animationStacksResolved.push_back(stack);
+    }
+
+    return animationStacksResolved;
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject* Document::GetObject(uint64_t id) const
+{
+    ObjectMap::const_iterator it = objects.find(id);
+    return it == objects.end() ? nullptr : (*it).second;
+}
+
+#define MAX_CLASSNAMES 6
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsSequenced(uint64_t id, const ConnectionMap& conns) const
+{
+    std::vector<const Connection*> temp;
+
+    const std::pair<ConnectionMap::const_iterator,ConnectionMap::const_iterator> range =
+        conns.equal_range(id);
+
+    temp.reserve(std::distance(range.first,range.second));
+    for (ConnectionMap::const_iterator it = range.first; it != range.second; ++it) {
+        temp.push_back((*it).second);
+    }
+
+    std::sort(temp.begin(), temp.end(), std::mem_fn(&Connection::Compare));
+
+    return temp; // NRVO should handle this
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsSequenced(uint64_t id, bool is_src,
+    const ConnectionMap& conns,
+    const char* const* classnames,
+    size_t count) const
+
+{
+    ai_assert(classnames);
+    ai_assert( count != 0 );
+    ai_assert( count <= MAX_CLASSNAMES);
+
+    size_t lengths[MAX_CLASSNAMES];
+
+    const size_t c = count;
+    for (size_t i = 0; i < c; ++i) {
+        lengths[ i ] = strlen(classnames[i]);
+    }
+
+    std::vector<const Connection*> temp;
+    const std::pair<ConnectionMap::const_iterator,ConnectionMap::const_iterator> range =
+        conns.equal_range(id);
+
+    temp.reserve(std::distance(range.first,range.second));
+    for (ConnectionMap::const_iterator it = range.first; it != range.second; ++it) {
+        const Token& key = (is_src
+            ? (*it).second->LazyDestinationObject()
+            : (*it).second->LazySourceObject()
+        ).GetElement().KeyToken();
+
+        const char* obtype = key.begin();
+
+        for (size_t i = 0; i < c; ++i) {
+            ai_assert(classnames[i]);
+            if(static_cast<size_t>(std::distance(key.begin(),key.end())) == lengths[i] && !strncmp(classnames[i],obtype,lengths[i])) {
+                obtype = nullptr;
+                break;
+            }
+        }
+
+        if(obtype) {
+            continue;
+        }
+
+        temp.push_back((*it).second);
+    }
+
+    std::sort(temp.begin(), temp.end(), std::mem_fn(&Connection::Compare));
+    return temp; // NRVO should handle this
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsBySourceSequenced(uint64_t source) const
+{
+    return GetConnectionsSequenced(source, ConnectionsBySource());
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsBySourceSequenced(uint64_t src, const char* classname) const
+{
+    const char* arr[] = {classname};
+    return GetConnectionsBySourceSequenced(src, arr,1);
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsBySourceSequenced(uint64_t source, 
+        const char* const* classnames, size_t count) const
+{
+    return GetConnectionsSequenced(source, true, ConnectionsBySource(),classnames, count);
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsByDestinationSequenced(uint64_t dest,
+        const char* classname) const
+{
+    const char* arr[] = {classname};
+    return GetConnectionsByDestinationSequenced(dest, arr,1);
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsByDestinationSequenced(uint64_t dest) const
+{
+    return GetConnectionsSequenced(dest, ConnectionsByDestination());
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsByDestinationSequenced(uint64_t dest,
+    const char* const* classnames, size_t count) const
+
+{
+    return GetConnectionsSequenced(dest, false, ConnectionsByDestination(),classnames, count);
+}
+
+// ------------------------------------------------------------------------------------------------
+Connection::Connection(uint64_t insertionOrder,  uint64_t src, uint64_t dest, const std::string& prop,
+        const Document& doc)
+
+: insertionOrder(insertionOrder)
+, prop(prop)
+, src(src)
+, dest(dest)
+, doc(doc)
+{
+    ai_assert(doc.Objects().find(src) != doc.Objects().end());
+    // dest may be 0 (root node)
+    ai_assert(!dest || doc.Objects().find(dest) != doc.Objects().end());
+}
+
+// ------------------------------------------------------------------------------------------------
+Connection::~Connection()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject& Connection::LazySourceObject() const
+{
+    LazyObject* const lazy = doc.GetObject(src);
+    ai_assert(lazy);
+    return *lazy;
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject& Connection::LazyDestinationObject() const
+{
+    LazyObject* const lazy = doc.GetObject(dest);
+    ai_assert(lazy);
+    return *lazy;
+}
+
+// ------------------------------------------------------------------------------------------------
+const Object* Connection::SourceObject() const
+{
+    LazyObject* const lazy = doc.GetObject(src);
+    ai_assert(lazy);
+    return lazy->Get();
+}
+
+// ------------------------------------------------------------------------------------------------
+const Object* Connection::DestinationObject() const
+{
+    LazyObject* const lazy = doc.GetObject(dest);
+    ai_assert(lazy);
+    return lazy->Get();
+}
+
+} // !FBX
+} // !Assimp
+
+#endif