Re-run VAO initialization next frame, if something goes wrong

Shaders might not have been compiled when the VAOs are initialized,
so the vertex attributes can't be set correctly. If this happens or
anything else that's not correct, make sure to re-run the whole VAO
initialization process next frame.

Task-number: QTBUG-56603
Change-Id: Ice8daa1732fa80dcb84dc02528360cefab74b819
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

2 files changed, 17 insertions, 6 deletions

diff --git a/src/render/backend/renderer.cpp b/src/render/backend/renderer.cpp
index 4c8eeecc1..88bce753f 100644
--- a/src/render/backend/renderer.cpp
+++ b/src/render/backend/renderer.cpp
@@ -770,8 +770,8 @@ void Renderer::prepareCommandsSubmission(const QVector<RenderView *> &renderView
                         vao->bind();
                         // Update or set Attributes and Buffers for the given rGeometry and Command
                         // Note: this fills m_dirtyAttributes as well
-                        updateVAOWithAttributes(rGeometry, command, shader, requiresFullVAOUpdate);
-                        vao->setSpecified(true);
+                        if (updateVAOWithAttributes(rGeometry, command, shader, requiresFullVAOUpdate))
+                            vao->setSpecified(true);
                     }
                 }
 
@@ -1392,6 +1392,12 @@ bool Renderer::executeCommandsSubmission(const RenderView *rv)
 
             vao = m_nodesManager->vaoManager()->data(command->m_vao);
 
+            // something may have went wrong when initializing the VAO
+            if (!vao->isSpecified()) {
+                allCommandsIssued = false;
+                continue;
+            }
+
             {
                 Profiling::GLTimeRecorder recorder(Profiling::ShaderUpdate);
                 //// We activate the shader here
@@ -1447,26 +1453,27 @@ bool Renderer::executeCommandsSubmission(const RenderView *rv)
     return allCommandsIssued;
 }
 
-void Renderer::updateVAOWithAttributes(Geometry *geometry,
+bool Renderer::updateVAOWithAttributes(Geometry *geometry,
                                        RenderCommand *command,
                                        Shader *shader,
                                        bool forceUpdate)
 {
     m_dirtyAttributes.reserve(m_dirtyAttributes.size() + geometry->attributes().size());
     const auto attributeIds = geometry->attributes();
+
     for (QNodeId attributeId : attributeIds) {
         // TO DO: Improvement we could store handles and use the non locking policy on the attributeManager
         Attribute *attribute = m_nodesManager->attributeManager()->lookupResource(attributeId);
 
         if (attribute == nullptr)
-            continue;
+            return false;
 
         Buffer *buffer = m_nodesManager->bufferManager()->lookupResource(attribute->bufferId());
 
         // Buffer update was already performed at this point
         // Just make sure the attribute reference a valid buffer
         if (buffer == nullptr)
-            continue;
+            return false;
 
         // Index Attribute
         bool attributeWasDirty = false;
@@ -1485,6 +1492,8 @@ void Renderer::updateVAOWithAttributes(Geometry *geometry,
                         break;
                     }
                 }
+                if (attributeLocation < 0)
+                    return false;
                 m_graphicsContext->specifyAttribute(attribute, buffer, attributeLocation);
             }
         }
@@ -1500,6 +1509,8 @@ void Renderer::updateVAOWithAttributes(Geometry *geometry,
         // should remain dirty so that VAO for these commands are properly
         // updated
     }
+
+    return true;
 }
 
 bool Renderer::requiresVAOAttributeUpdate(Geometry *geometry,
diff --git a/src/render/backend/renderer_p.h b/src/render/backend/renderer_p.h
index cb78cbef3..9f6e8d857 100644
--- a/src/render/backend/renderer_p.h
+++ b/src/render/backend/renderer_p.h
@@ -212,7 +212,7 @@ public:
 
     void prepareCommandsSubmission(const QVector<RenderView *> &renderViews);
     bool executeCommandsSubmission(const RenderView *rv);
-    void updateVAOWithAttributes(Geometry *geometry,
+    bool updateVAOWithAttributes(Geometry *geometry,
                                  RenderCommand *command,
                                  Shader *shader,
                                  bool forceUpdate);