Remove backend entity hierarchy rebuilding jobs

We no longer need to have a special job to rebuild the entity
hierarchy as parent nodes can now always be resolved on the
backend either at creation time or while reparenting.

The NodePostConstructorInit ensure that all backend nodes are
created from the top down so a node can always find it's
parent.

Change-Id: I9dcfb64b62e2e02b89b1ae59efb41f25dfc09eae
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 102 insertions, 116 deletions

diff --git a/tests/auto/render/entity/tst_entity.cpp b/tests/auto/render/entity/tst_entity.cpp
index 7e5150a77..463fbbb79 100644
--- a/tests/auto/render/entity/tst_entity.cpp
+++ b/tests/auto/render/entity/tst_entity.cpp
@@ -182,7 +182,6 @@ private slots:
         entity.cleanup();
 
         // THEN
-        QVERIFY(entity.parentEntityId().isNull());
         QVERIFY(entity.componentUuid<Transform>().isNull());
         QVERIFY(entity.componentUuid<CameraLens>().isNull());
         QVERIFY(entity.componentUuid<Material>().isNull());
@@ -201,29 +200,18 @@ private slots:
         QVERIFY(!containsAll);
     }
 
-    void checkRebuildingEntityHierarchy()
+    void checkEntityReparenting()
     {
         // GIVEN
         TestRenderer renderer;
         NodeManagers nodeManagers;
         Qt3DCore::QEntity frontendEntityA, frontendEntityB, frontendEntityC;
 
-        auto entityCreator = [&nodeManagers, &renderer](const Qt3DCore::QEntity &frontEndEntity) {
-            Entity *entity = nodeManagers.renderNodesManager()->getOrCreateResource(frontEndEntity.id());
-            entity->setNodeManagers(&nodeManagers);
-            entity->setRenderer(&renderer);
-            return entity;
-        };
-
-        auto backendA = entityCreator(frontendEntityA);
-        auto backendB = entityCreator(frontendEntityB);
-        auto backendC = entityCreator(frontendEntityC);
+        auto backendA = createEntity(renderer, nodeManagers, frontendEntityA);
+        auto backendB = createEntity(renderer, nodeManagers, frontendEntityB);
+        auto backendC = createEntity(renderer, nodeManagers, frontendEntityC);
 
         // THEN
-        QVERIFY(backendA->parentEntityId().isNull());
-        QVERIFY(backendB->parentEntityId().isNull());
-        QVERIFY(backendC->parentEntityId().isNull());
-
         QVERIFY(backendA->parent() == nullptr);
         QVERIFY(backendB->parent() == nullptr);
         QVERIFY(backendC->parent() == nullptr);
@@ -233,9 +221,6 @@ private slots:
         QVERIFY(backendC->childrenHandles().isEmpty());
 
         // WHEN
-        renderer.clearDirtyBits(0);
-        QVERIFY(renderer.dirtyBits() == 0);
-
         auto sendParentChange = [&nodeManagers](const Qt3DCore::QEntity &entity) {
             Entity *backendEntity = nodeManagers.renderNodesManager()->getOrCreateResource(entity.id());
             backendEntity->syncFromFrontEnd(&entity, false);
@@ -248,68 +233,111 @@ private slots:
         sendParentChange(frontendEntityC);
 
         // THEN
-        QVERIFY(renderer.dirtyBits() & AbstractRenderer::EntityHierarchyDirty);
+        QVERIFY(backendA->parent() == nullptr);
+        QVERIFY(backendB->parent() == backendA);
+        QVERIFY(backendC->parent() == backendB);
 
-        QVERIFY(backendA->parentEntityId().isNull());
-        QVERIFY(backendB->parentEntityId() == frontendEntityA.id());
-        QVERIFY(backendC->parentEntityId() == frontendEntityB.id());
+        QCOMPARE(backendA->childrenHandles().count(), 1);
+        QCOMPARE(backendB->childrenHandles().count(), 1);
+        QVERIFY(backendC->childrenHandles().isEmpty());
 
+          // WHEN - reparent C to A
+        frontendEntityC.setParent(&frontendEntityA);
+        sendParentChange(frontendEntityC);
+
+        // THEN
+        QVERIFY(backendA->parent() == nullptr);
+        QVERIFY(backendB->parent() == backendA);
+        QVERIFY(backendC->parent() == backendA);
+
+        QCOMPARE(backendA->childrenHandles().size(), 2);
+        QVERIFY(backendB->childrenHandles().isEmpty());
+        QVERIFY(backendC->childrenHandles().isEmpty());
+
+        // WHEN - reparent B to null.
+        frontendEntityB.setParent(static_cast<Qt3DCore::QNode *>(nullptr));
+        sendParentChange(frontendEntityB);
+
+        // THEN
         QVERIFY(backendA->parent() == nullptr);
         QVERIFY(backendB->parent() == nullptr);
-        QVERIFY(backendC->parent() == nullptr);
+        QVERIFY(backendC->parent() == backendA);
 
-        QVERIFY(backendA->childrenHandles().isEmpty());
+        QCOMPARE(backendA->childrenHandles().count(), 1);
+        QVERIFY(!backendA->childrenHandles().contains(backendB->handle()));
         QVERIFY(backendB->childrenHandles().isEmpty());
         QVERIFY(backendC->childrenHandles().isEmpty());
+      }
+
+    void checkEntityCleanup()
+    {
+        // GIVEN
+        TestRenderer renderer;
+        NodeManagers nodeManagers;
+        Qt3DCore::QEntity frontendEntityA, frontendEntityB, frontendEntityC;
+
+        auto backendA = createEntity(renderer, nodeManagers, frontendEntityA);
+        auto backendB = createEntity(renderer, nodeManagers, frontendEntityB);
+        auto backendC = createEntity(renderer, nodeManagers, frontendEntityC);
 
         // WHEN
-        auto rebuildHierarchy = [](Entity *backend) {
-            backend->clearEntityHierarchy();
-            backend->rebuildEntityHierarchy();
+        auto sendParentChange = [&nodeManagers](const Qt3DCore::QEntity &entity) {
+            Entity *backendEntity = nodeManagers.renderNodesManager()->getOrCreateResource(entity.id());
+            backendEntity->syncFromFrontEnd(&entity, false);
         };
-        rebuildHierarchy(backendA);
-        rebuildHierarchy(backendB);
-        rebuildHierarchy(backendC);
+
+        // reparent B and C to A.
+        frontendEntityB.setParent(&frontendEntityA);
+        sendParentChange(frontendEntityB);
+        frontendEntityC.setParent(&frontendEntityA);
+        sendParentChange(frontendEntityC);
 
         // THEN
         QVERIFY(backendA->parent() == nullptr);
         QVERIFY(backendB->parent() == backendA);
-        QVERIFY(backendC->parent() == backendB);
+        QVERIFY(backendC->parent() == backendA);
 
-        QVERIFY(!backendA->childrenHandles().isEmpty());
-        QVERIFY(!backendB->childrenHandles().isEmpty());
+        QCOMPARE(backendA->childrenHandles().count(), 2);
+        QVERIFY(backendB->childrenHandles().isEmpty());
         QVERIFY(backendC->childrenHandles().isEmpty());
 
-        // WHEN - reparent B to null.
-        frontendEntityB.setParent(static_cast<Qt3DCore::QNode *>(nullptr));
-        sendParentChange(frontendEntityB);
-        rebuildHierarchy(backendA);
-        rebuildHierarchy(backendB);
-        rebuildHierarchy(backendC);
+        // WHEN - cleaning up a child
+        backendC->cleanup();
+
+        // THEN - the child's parent should be null and it
+        // should be removed from its parent's list of children
+        QVERIFY(backendA->parent() == nullptr);
+        QVERIFY(backendB->parent() == backendA);
+        QVERIFY(backendC->parent() == nullptr);
+
+        QCOMPARE(backendA->childrenHandles().count(), 1);
+        QVERIFY(!backendA->childrenHandles().contains(backendC->handle()));
+        QVERIFY(backendB->childrenHandles().isEmpty());
+        QVERIFY(backendC->childrenHandles().isEmpty());
 
-        QVERIFY(backendA->parentEntityId().isNull());
-        QVERIFY(backendB->parentEntityId().isNull());
-        QVERIFY(backendC->parentEntityId() == frontendEntityB.id());
+        // WHEN (cleaning up parent)
+        backendA->cleanup();
 
+        // THEN  (it's children's parent should be set to null)
         QVERIFY(backendA->parent() == nullptr);
         QVERIFY(backendB->parent() == nullptr);
-        QVERIFY(backendC->parent() == backendB);
+        QVERIFY(backendC->parent() == nullptr);
 
         QVERIFY(backendA->childrenHandles().isEmpty());
-        QVERIFY(!backendB->childrenHandles().isEmpty());
+        QVERIFY(backendB->childrenHandles().isEmpty());
         QVERIFY(backendC->childrenHandles().isEmpty());
 
-        // WHEN - cleanup
-        backendA->cleanup();
+        // WHEN
         backendB->cleanup();
-        backendC->cleanup();
 
-        // THEN
-        QVERIFY(backendA->parentEntityId().isNull());
-        QVERIFY(backendB->parentEntityId().isNull());
-        QVERIFY(backendC->parentEntityId().isNull());
+        // THEN nothing should change
+        QVERIFY(backendA->childrenHandles().isEmpty());
+        QVERIFY(backendB->childrenHandles().isEmpty());
+        QVERIFY(backendC->childrenHandles().isEmpty());
 
-        QVERIFY(renderer.dirtyBits() != 0);
+        QVERIFY(backendA->parent() == nullptr);
+        QVERIFY(backendB->parent() == nullptr);
+        QVERIFY(backendC->parent() == nullptr);
     }
 
     void shouldHandleSingleComponentEvents_data()
@@ -441,19 +469,9 @@ private slots:
         NodeManagers nodeManagers;
         Qt3DCore::QEntity frontendEntityA, frontendEntityB, frontendEntityC;
 
-        auto entityCreator = [&nodeManagers, &renderer](const Qt3DCore::QEntity &frontEndEntity) {
-            HEntity renderNodeHandle = nodeManagers.renderNodesManager()->getOrAcquireHandle(frontEndEntity.id());
-            Entity *entity = nodeManagers.renderNodesManager()->data(renderNodeHandle);
-            entity->setNodeManagers(&nodeManagers);
-            entity->setHandle(renderNodeHandle);
-            entity->setRenderer(&renderer);
-            entity->syncFromFrontEnd(&frontEndEntity, true);
-            return entity;
-        };
-
-        auto backendA = entityCreator(frontendEntityA);
-        auto backendB = entityCreator(frontendEntityB);
-        auto backendC = entityCreator(frontendEntityC);
+        auto backendA = createEntity(renderer, nodeManagers, frontendEntityA);
+        auto backendB = createEntity(renderer, nodeManagers, frontendEntityB);
+        auto backendC = createEntity(renderer, nodeManagers, frontendEntityC);
 
         auto sendParentChange = [&nodeManagers](const Qt3DCore::QEntity &entity) {
             Entity *backendEntity = nodeManagers.renderNodesManager()->getOrCreateResource(entity.id());
@@ -466,14 +484,6 @@ private slots:
         frontendEntityC.setParent(&frontendEntityB);
         sendParentChange(frontendEntityC);
 
-        auto rebuildHierarchy = [](Entity *backend) {
-            backend->clearEntityHierarchy();
-            backend->rebuildEntityHierarchy();
-        };
-        rebuildHierarchy(backendA);
-        rebuildHierarchy(backendB);
-        rebuildHierarchy(backendC);
-
         // WHEN
         int visitCount = 0;
         auto counter = [&visitCount](const Entity *) { ++visitCount; };
@@ -494,19 +504,9 @@ private slots:
         frontendEntityB.setEnabled(false);
         frontendEntityC.setEnabled(false);
 
-        auto entityCreator = [&nodeManagers, &renderer](const Qt3DCore::QEntity &frontEndEntity) {
-            HEntity renderNodeHandle = nodeManagers.renderNodesManager()->getOrAcquireHandle(frontEndEntity.id());
-            Entity *entity = nodeManagers.renderNodesManager()->data(renderNodeHandle);
-            entity->setNodeManagers(&nodeManagers);
-            entity->setHandle(renderNodeHandle);
-            entity->setRenderer(&renderer);
-            entity->syncFromFrontEnd(&frontEndEntity, true);
-            return entity;
-        };
-
-        auto backendA = entityCreator(frontendEntityA);
-        auto backendB = entityCreator(frontendEntityB);
-        auto backendC = entityCreator(frontendEntityC);
+        auto backendA = createEntity(renderer, nodeManagers, frontendEntityA);
+        auto backendB = createEntity(renderer, nodeManagers, frontendEntityB);
+        auto backendC = createEntity(renderer, nodeManagers, frontendEntityC);
 
         auto sendParentChange = [&nodeManagers](const Qt3DCore::QEntity &entity) {
             Entity *backendEntity = nodeManagers.renderNodesManager()->getOrCreateResource(entity.id());
@@ -519,14 +519,6 @@ private slots:
         frontendEntityC.setParent(&frontendEntityB);
         sendParentChange(frontendEntityC);
 
-        auto rebuildHierarchy = [](Entity *backend) {
-            backend->clearEntityHierarchy();
-            backend->rebuildEntityHierarchy();
-        };
-        rebuildHierarchy(backendA);
-        rebuildHierarchy(backendB);
-        rebuildHierarchy(backendC);
-
        // WHEN
        CompleteVisitor v1(&nodeManagers);
        EnabledVisitor v2(&nodeManagers);
@@ -553,19 +545,9 @@ private slots:
         frontendEntityB.setEnabled(false);
         frontendEntityC.setEnabled(false);
 
-        auto entityCreator = [&nodeManagers, &renderer](const Qt3DCore::QEntity &frontEndEntity) {
-            HEntity renderNodeHandle = nodeManagers.renderNodesManager()->getOrAcquireHandle(frontEndEntity.id());
-            Entity *entity = nodeManagers.renderNodesManager()->data(renderNodeHandle);
-            entity->setNodeManagers(&nodeManagers);
-            entity->setHandle(renderNodeHandle);
-            entity->setRenderer(&renderer);
-            entity->syncFromFrontEnd(&frontEndEntity, true);
-            return entity;
-        };
-
-        auto backendA = entityCreator(frontendEntityA);
-        auto backendB = entityCreator(frontendEntityB);
-        auto backendC = entityCreator(frontendEntityC);
+        auto backendA = createEntity(renderer, nodeManagers, frontendEntityA);
+        auto backendB = createEntity(renderer, nodeManagers, frontendEntityB);
+        auto backendC = createEntity(renderer, nodeManagers, frontendEntityC);
 
         auto sendParentChange = [&nodeManagers](const Qt3DCore::QEntity &entity) {
             Entity *backendEntity = nodeManagers.renderNodesManager()->getOrCreateResource(entity.id());
@@ -578,14 +560,6 @@ private slots:
         frontendEntityC.setParent(&frontendEntityB);
         sendParentChange(frontendEntityC);
 
-        auto rebuildHierarchy = [](Entity *backend) {
-            backend->clearEntityHierarchy();
-            backend->rebuildEntityHierarchy();
-        };
-        rebuildHierarchy(backendA);
-        rebuildHierarchy(backendB);
-        rebuildHierarchy(backendC);
-
         // WHEN
         EntityAccumulator v1(&nodeManagers);
         EntityAccumulator v2([](Entity *e) { return e->isEnabled(); }, &nodeManagers);
@@ -596,6 +570,18 @@ private slots:
         QCOMPARE(r1.count(), 3);
         QCOMPARE(r2.count(), 0);
     }
+
+private:
+    Entity *createEntity(TestRenderer &renderer, NodeManagers &nodeManagers, const Qt3DCore::QEntity &frontEndEntity) {
+        HEntity renderNodeHandle = nodeManagers.renderNodesManager()->getOrAcquireHandle(frontEndEntity.id());
+        Entity *entity = nodeManagers.renderNodesManager()->data(renderNodeHandle);
+        entity->setNodeManagers(&nodeManagers);
+        entity->setHandle(renderNodeHandle);
+        entity->setRenderer(&renderer);
+        entity->syncFromFrontEnd(&frontEndEntity, true);
+        return entity;
+    }
+
 };
 
 QTEST_APPLESS_MAIN(tst_RenderEntity)