Fix partial rebuilds and geometry changes.

When we do partial rebuilds, we need to update the render order
for the entire subtree unconditionally. The previous logic
was to reuse existing render orders beneath batch roots, which
caused overlapping orders to be used.

When geometry of an alpha batch changes, we need to rebuild
everything under the current root. Otherwise, we might end
up with previously batched content which incorrectly
overlaps the changed geometry.

Change-Id: I7b6de5ce34a02434294ac5ae29ae1b87eb3c4464
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

1 files changed, 29 insertions, 20 deletions

diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
index 7291af9c46..2ffbdb26bb 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
@@ -195,7 +195,7 @@ void qsg_dumpShadowRoots(BatchRootInfo *i, int indent)
     if (!i) {
         qDebug() << ind.constData() << "- no info";
     } else {
-        qDebug() << ind.constData() << "- parent:" << i->parentRoot;
+        qDebug() << ind.constData() << "- parent:" << i->parentRoot << "orders" << i->firstOrder << "->" << i->lastOrder << ", avail:" << i->availableOrders;
         for (QSet<Node *>::const_iterator it = i->subRoots.constBegin();
              it != i->subRoots.constEnd(); ++it) {
             qDebug() << ind.constData() << "-" << *it;
@@ -217,7 +217,10 @@ void qsg_dumpShadowRoots(Node *n)
         qDebug() << ind.constData() << "[X]" << n->sgNode << hex << uint(n->sgNode->flags());
         qsg_dumpShadowRoots(n->rootInfo(), indent);
     } else {
-        qDebug() << ind.constData() << "[ ]" << n->sgNode << hex << uint(n->sgNode->flags());
+        QDebug d = qDebug();
+        d << ind.constData() << "[ ]" << n->sgNode << hex << uint(n->sgNode->flags());
+        if (n->type() == QSGNode::GeometryNodeType)
+            d << "order" << dec << n->element()->order;
     }
 
     SHADOWNODE_TRAVERSE(n)
@@ -623,7 +626,8 @@ Renderer::Renderer(QSGContext *ctx)
     , m_opaqueRenderList(64)
     , m_alphaRenderList(64)
     , m_nextRenderOrder(0)
-    , m_explicitOrdering(false)
+    , m_partialRebuild(false)
+    , m_partialRebuildRoot(0)
     , m_opaqueBatches(16)
     , m_alphaBatches(16)
     , m_batchPool(16)
@@ -1026,7 +1030,12 @@ void Renderer::nodeChanged(QSGNode *node, QSGNode::DirtyState state)
                 if (!e->batch->geometryWasChanged(gn)) {
                     m_rebuild |= Renderer::FullRebuild;
                 } else if (!b->isOpaque) {
-                    m_rebuild |= Renderer::BuildBatches;
+                    if (e->root) {
+                        m_taggedRoots << e->root;
+                        m_rebuild |= BuildRenderListsForTaggedRoots;
+                    } else {
+                        m_rebuild |= FullRebuild;
+                    }
                 } else {
                     b->needsUpload = true;
                 }
@@ -1034,8 +1043,7 @@ void Renderer::nodeChanged(QSGNode *node, QSGNode::DirtyState state)
         }
     }
 
-    if (state & QSGNode::DirtyMaterial) {
-        Q_ASSERT(node->type() == QSGNode::GeometryNodeType);
+    if (state & QSGNode::DirtyMaterial && node->type() == QSGNode::GeometryNodeType) {
         Element *e = shadowNode->element();
         if (e) {
             if (e->batch) {
@@ -1108,30 +1116,27 @@ void Renderer::buildRenderLists(QSGNode *node)
             m_alphaRenderList << e;
 
         e->order = ++m_nextRenderOrder;
-
         // Used while rebuilding partial roots.
-        if (m_explicitOrdering)
+        if (m_partialRebuild)
             e->orphaned = false;
 
     } else if (node->type() == QSGNode::ClipNodeType || shadowNode->isBatchRoot) {
         Q_ASSERT(m_nodes.contains(node));
         BatchRootInfo *info = batchRootInfo(m_nodes.value(node));
-        Q_ASSERT(!m_explicitOrdering || info->firstOrder >= 0);
-        Q_ASSERT(!m_explicitOrdering || info->lastOrder >= 0);
-
-        if (m_explicitOrdering)
+        if (node == m_partialRebuildRoot) {
             m_nextRenderOrder = info->firstOrder;
-        int currentOrder = m_nextRenderOrder;
-        QSGNODE_TRAVERSE(node)
-                buildRenderLists(child);
-        int padding = (m_nextRenderOrder - currentOrder) >> 2;
-        if (m_explicitOrdering) {
+            QSGNODE_TRAVERSE(node)
+                    buildRenderLists(child);
             m_nextRenderOrder = info->lastOrder + 1;
         } else {
+            int currentOrder = m_nextRenderOrder;
+            QSGNODE_TRAVERSE(node)
+                buildRenderLists(child);
+            int padding = (m_nextRenderOrder - currentOrder) >> 2;
             info->firstOrder = currentOrder;
             info->availableOrders = padding;
             info->lastOrder = m_nextRenderOrder + padding;
-            m_nextRenderOrder += padding;
+            m_nextRenderOrder = info->lastOrder;
         }
         return;
     } else if (node->type() == QSGNode::RenderNodeType) {
@@ -1226,7 +1231,7 @@ void Renderer::buildRenderListsForTaggedRoots()
     m_opaqueRenderList.reset();
     m_alphaRenderList.reset();
     int maxRenderOrder = m_nextRenderOrder;
-    m_explicitOrdering = true;
+    m_partialRebuild = true;
     // Traverse each root, assigning it
     for (QSet<Node *>::const_iterator it = m_taggedRoots.constBegin();
          it != m_taggedRoots.constEnd(); ++it) {
@@ -1235,11 +1240,13 @@ void Renderer::buildRenderListsForTaggedRoots()
         if ((!i->parentRoot || !m_taggedRoots.contains(i->parentRoot))
              && !nodeUpdater()->isNodeBlocked(root->sgNode, rootNode())) {
             m_nextRenderOrder = i->firstOrder;
+            m_partialRebuildRoot = root->sgNode;
             buildRenderLists(root->sgNode);
         }
     }
+    m_partialRebuild = false;
+    m_partialRebuildRoot = 0;
     m_taggedRoots.clear();
-    m_explicitOrdering = false;
     m_nextRenderOrder = qMax(m_nextRenderOrder, maxRenderOrder);
 
     // Add orphaned elements back into the list and then sort it..
@@ -1787,6 +1794,7 @@ void Renderer::renderMergedBatch(const Batch *batch)
     if (Q_UNLIKELY(debug_render)) {
         QDebug debug = qDebug();
         debug << " -"
+              << batch
               << (batch->uploadedThisFrame ? "[  upload]" : "[retained]")
               << (e->node->clipList() ? "[  clip]" : "[noclip]")
               << (batch->isOpaque ? "[opaque]" : "[ alpha]")
@@ -1864,6 +1872,7 @@ void Renderer::renderUnmergedBatch(const Batch *batch)
 
     if (Q_UNLIKELY(debug_render)) {
         qDebug() << " -"
+                 << batch
                  << (batch->uploadedThisFrame ? "[  upload]" : "[retained]")
                  << (e->node->clipList() ? "[  clip]" : "[noclip]")
                  << (batch->isOpaque ? "[opaque]" : "[ alpha]")