Fix mesh preview flashback

Before this commit, outdated textured preview will override the updated untextured preview. From user's perspective, sometimes, the mesh preview flashback for a short time span, although it will finally been updated to the latest.

src/document.cpp

@@ -59,7 +59,9 @@ Document::Document() :
     m_posePreviewsGenerator(nullptr),
     m_currentRigSucceed(false),
     m_materialPreviewsGenerator(nullptr),
-    m_motionsGenerator(nullptr)
+    m_motionsGenerator(nullptr),
+    m_meshGenerationId(0),
+    m_nextMeshGenerationId(1)
 {
     connect(&Preferences::instance(), &Preferences::partColorChanged, this, &Document::applyPreferencePartColorChange);
     connect(&Preferences::instance(), &Preferences::flatShadingChanged, this, &Document::applyPreferenceFlatShadingChange);
@@ -1754,6 +1756,7 @@ void Document::generateMesh()
     toSnapshot(snapshot);
     resetDirtyFlags();
     m_meshGenerator = new MeshGenerator(snapshot);
+    m_meshGenerator->setId(m_nextMeshGenerationId++);
     m_meshGenerator->setDefaultPartColor(Preferences::instance().partColor());
     m_meshGenerator->setGeneratedCacheContext(&m_generatedCacheContext);
     if (!m_smoothNormal) {

src/document.h

@@ -689,6 +689,8 @@ private: // need initialize
     bool m_currentRigSucceed;
     MaterialPreviewsGenerator *m_materialPreviewsGenerator;
     MotionsGenerator *m_motionsGenerator;
+    quint64 m_meshGenerationId;
+    quint64 m_nextMeshGenerationId;
 private:
     static unsigned long m_maxSnapshot;
     std::deque<HistoryItem> m_undoItems;

src/documentwindow.cpp

@@ -118,7 +118,8 @@ DocumentWindow::DocumentWindow() :
     m_documentSaved(true),
     m_exportPreviewWidget(nullptr),
     m_preferencesWidget(nullptr),
-    m_isLastMeshGenerationSucceed(true)
+    m_isLastMeshGenerationSucceed(true),
+    m_currentUpdatedMeshId(0)
 {
     if (!g_logBrowser) {
         g_logBrowser = new LogBrowser;
@@ -920,11 +921,21 @@ DocumentWindow::DocumentWindow() :
     connect(m_document, &Document::resultTextureChanged, [=]() {
         if (m_document->isMeshGenerating())
             return;
-        m_modelRenderWidget->updateMesh(m_document->takeResultTextureMesh());
+        auto resultTextureMesh = m_document->takeResultTextureMesh();
+        if (nullptr != resultTextureMesh) {
+            if (resultTextureMesh->meshId() < m_currentUpdatedMeshId) {
+                delete resultTextureMesh;
+                return;
+            }
+        }
+        m_modelRenderWidget->updateMesh(resultTextureMesh);
     });
     
     connect(m_document, &Document::resultMeshChanged, [=]() {
-        m_modelRenderWidget->updateMesh(m_document->takeResultMesh());
+        auto resultMesh = m_document->takeResultMesh();
+        if (nullptr != resultMesh)
+            m_currentUpdatedMeshId = resultMesh->meshId();
+        m_modelRenderWidget->updateMesh(resultMesh);
     });
     
     connect(m_document, &Document::posesChanged, m_document, &Document::generateMotions);

src/documentwindow.h

@@ -80,6 +80,7 @@ private:
     PreferencesWidget *m_preferencesWidget;
     std::vector<QWidget *> m_dialogs;
     bool m_isLastMeshGenerationSucceed;
+    quint64 m_currentUpdatedMeshId;
 private:
     QString m_currentFilename;
     

src/meshgenerator.cpp

@@ -31,6 +31,16 @@ MeshGenerator::~MeshGenerator()
     delete m_nodesCutFaces;
 }
 
+void MeshGenerator::setId(quint64 id)
+{
+    m_id = id;
+}
+
+quint64 MeshGenerator::id()
+{
+    return m_id;
+}
+
 bool MeshGenerator::isSucceed()
 {
     return m_isSucceed;
@@ -1056,6 +1066,7 @@ void MeshGenerator::generate()
     countTimeConsumed.start();
     
     m_outcome = new Outcome;
+    m_outcome->meshId = m_id;
     //m_cutFaceTransforms = new std::map<QUuid, nodemesh::Builder::CutFaceTransform>;
     //m_nodesCutFaces = new std::map<QUuid, std::map<QString, QVector2D>>;
     

src/meshgenerator.h

@@ -66,6 +66,8 @@ public:
     void setGeneratedCacheContext(GeneratedCacheContext *cacheContext);
     void setSmoothShadingThresholdAngleDegrees(float degrees);
     void setDefaultPartColor(const QColor &color);
+    void setId(quint64 id);
+    quint64 id();
 signals:
     void finished();
 public slots:
@@ -91,6 +93,7 @@ private:
     float m_smoothShadingThresholdAngleDegrees = 60;
     std::map<QUuid, nodemesh::Builder::CutFaceTransform> *m_cutFaceTransforms = nullptr;
     std::map<QUuid, std::map<QString, QVector2D>> *m_nodesCutFaces = nullptr;
+    quint64 m_id = 0;
     
     void collectParts();
     bool checkIsComponentDirty(const QString &componentIdString);

src/meshloader.cpp

@@ -54,6 +54,7 @@ MeshLoader::MeshLoader(const MeshLoader &mesh) :
     this->m_faces = mesh.m_faces;
     this->m_triangulatedVertices = mesh.m_triangulatedVertices;
     this->m_triangulatedFaces = mesh.m_triangulatedFaces;
+    this->m_meshId = mesh.meshId();
 }
 
 MeshLoader::MeshLoader(ShaderVertex *triangleVertices, int vertexNum) :
@@ -106,6 +107,7 @@ MeshLoader::MeshLoader(Outcome &outcome) :
     m_edgeVertexCount(0),
     m_textureImage(nullptr)
 {
+    m_meshId = outcome.meshId;
     m_vertices = outcome.vertices;
     m_faces = outcome.triangleAndQuads;
     
@@ -349,3 +351,13 @@ void MeshLoader::updateTool(ShaderVertex *toolVertices, int vertexNum)
     m_toolVertices = toolVertices;
     m_toolVertexCount = vertexNum;
 }
+
+quint64 MeshLoader::meshId() const
+{
+    return m_meshId;
+}
+
+void MeshLoader::setMeshId(quint64 id)
+{
+    m_meshId = id;
+}

src/meshloader.h

@@ -54,6 +54,8 @@ public:
     void exportAsObj(const QString &filename);
     void exportAsObj(QTextStream *textStream);
     void updateTool(ShaderVertex *toolVertices, int vertexNum);
+    quint64 meshId() const;
+    void setMeshId(quint64 id);
 private:
     ShaderVertex *m_triangleVertices = nullptr;
     int m_triangleVertexCount = 0;
@@ -71,6 +73,7 @@ private:
     bool m_hasMetalnessInImage = false;
     bool m_hasRoughnessInImage = false;
     bool m_hasAmbientOcclusionInImage = false;
+    quint64 m_meshId = 0;
 };
 
 #endif

src/outcome.h

@@ -35,6 +35,7 @@ public:
     std::vector<std::vector<size_t>> triangles;
     std::vector<QVector3D> triangleNormals;
     std::vector<QColor> triangleColors;
+    quint64 meshId = 0;
     
     const std::vector<std::pair<QUuid, QUuid>> *triangleSourceNodes() const
     {