Allow multiple instances of a few render states

Allow more than one instance of BlendEquationArgumentsMask and
ClipPlaneMask render states.

Task-number: QTBUG-77735
Change-Id: I9d2bdc82843e2eaf0f8a781208e4ca10e3a777c7
Reviewed-by: Mike Krus <mike.krus@kdab.com>
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

5 files changed, 29 insertions, 14 deletions

diff --git a/src/render/renderers/opengl/jobs/renderviewjobutils.cpp b/src/render/renderers/opengl/jobs/renderviewjobutils.cpp
index 49e85e1d3..364a04ed3 100644
--- a/src/render/renderers/opengl/jobs/renderviewjobutils.cpp
+++ b/src/render/renderers/opengl/jobs/renderviewjobutils.cpp
@@ -196,7 +196,7 @@ void setRenderViewConfigFromFrameGraphLeafNode(RenderView *rv, const FrameGraphN
                 // Add states from new stateSet we might be missing
                 // but don' t override existing states (lower StateSetNode always has priority)
                 if (rStateSet->hasRenderStates())
-                    addUniqueStatesToRenderStateSet(stateSet, rStateSet->renderStates(), manager->renderStateManager());
+                    addStatesToRenderStateSet(stateSet, rStateSet->renderStates(), manager->renderStateManager());
                 break;
             }
 
@@ -420,13 +420,13 @@ void parametersFromMaterialEffectTechnique(ParameterInfoList *infoList,
 }
 
 // Only add states with types we don't already have
-void addUniqueStatesToRenderStateSet(RenderStateSet *stateSet,
-                                     const QVector<Qt3DCore::QNodeId> stateIds,
-                                     RenderStateManager *manager)
+void addStatesToRenderStateSet(RenderStateSet *stateSet,
+                               const QVector<Qt3DCore::QNodeId> stateIds,
+                               RenderStateManager *manager)
 {
     for (const Qt3DCore::QNodeId &stateId : stateIds) {
         RenderStateNode *node = manager->lookupResource(stateId);
-        if (node->isEnabled() && !stateSet->hasStateOfType(node->type())) {
+        if (node->isEnabled() && stateSet->canAddStateOfType(node->type())) {
             stateSet->addState(node->impl());
         }
     }
diff --git a/src/render/renderers/opengl/jobs/renderviewjobutils_p.h b/src/render/renderers/opengl/jobs/renderviewjobutils_p.h
index bd2e12534..b2fa59785 100644
--- a/src/render/renderers/opengl/jobs/renderviewjobutils_p.h
+++ b/src/render/renderers/opengl/jobs/renderviewjobutils_p.h
@@ -150,9 +150,9 @@ void parametersFromParametersProvider(ParameterInfoList *infoList,
 Q_AUTOTEST_EXPORT ParameterInfoList::const_iterator findParamInfo(ParameterInfoList *infoList,
                                                                   const int nameId);
 
-Q_AUTOTEST_EXPORT void addUniqueStatesToRenderStateSet(RenderStateSet *stateSet,
-                                                       const QVector<Qt3DCore::QNodeId> stateIds,
-                                                       RenderStateManager *manager);
+Q_AUTOTEST_EXPORT void addStatesToRenderStateSet(RenderStateSet *stateSet,
+                                                 const QVector<Qt3DCore::QNodeId> stateIds,
+                                                 RenderStateManager *manager);
 
 typedef QHash<int, QVariant> UniformBlockValueBuilderHash;
 
diff --git a/src/render/renderers/opengl/renderer/renderview.cpp b/src/render/renderers/opengl/renderer/renderview.cpp
index 62758bb53..09099ee02 100644
--- a/src/render/renderers/opengl/renderer/renderview.cpp
+++ b/src/render/renderers/opengl/renderer/renderview.cpp
@@ -603,7 +603,7 @@ QVector<RenderCommand *> RenderView::buildDrawRenderCommands(const QVector<Entit
                 RenderPass *pass = passData.pass;
                 if (pass->hasRenderStates()) {
                     command->m_stateSet = new RenderStateSet();
-                    addUniqueStatesToRenderStateSet(command->m_stateSet, pass->renderStates(), m_manager->renderStateManager());
+                    addStatesToRenderStateSet(command->m_stateSet, pass->renderStates(), m_manager->renderStateManager());
                     if (m_stateSet != nullptr)
                         command->m_stateSet->merge(m_stateSet);
                     command->m_changeCost = m_renderer->defaultRenderState()->changeCost(command->m_stateSet);
@@ -723,7 +723,7 @@ QVector<RenderCommand *> RenderView::buildComputeRenderCommands(const QVector<En
 
                 if (pass->hasRenderStates()) {
                     command->m_stateSet = new RenderStateSet();
-                    addUniqueStatesToRenderStateSet(command->m_stateSet, pass->renderStates(), m_manager->renderStateManager());
+                    addStatesToRenderStateSet(command->m_stateSet, pass->renderStates(), m_manager->renderStateManager());
 
                     // Merge per pass stateset with global stateset
                     // so that the local stateset only overrides
diff --git a/src/render/renderers/opengl/renderstates/renderstateset.cpp b/src/render/renderers/opengl/renderstates/renderstateset.cpp
index b14695c77..d667d9c76 100644
--- a/src/render/renderers/opengl/renderstates/renderstateset.cpp
+++ b/src/render/renderers/opengl/renderstates/renderstateset.cpp
@@ -112,17 +112,28 @@ void RenderStateSet::merge(RenderStateSet *other)
 
     // We only add states which are new (different type)
     for (const StateVariant &otherState : otherStates) {
-        const bool hasFoundStateOfSameType = hasStateOfType(otherState.type);
-        if (!hasFoundStateOfSameType)
+        const bool canAdd = canAddStateOfType(otherState.type);
+        if (canAdd)
             m_states.push_back(otherState);
     }
 }
 
+bool RenderStateSet::canAddStateOfType(StateMask type) const
+{
+    return !hasStateOfType(type) || allowMultipleStatesOfType(type);
+}
+
 bool RenderStateSet::hasStateOfType(StateMask type) const
 {
     return (type & stateMask());
 }
 
+bool RenderStateSet::allowMultipleStatesOfType(StateMask type) const
+{
+    return (type == BlendEquationArgumentsMask) ||
+           (type == ClipPlaneMask);
+}
+
 bool RenderStateSet::contains(const StateVariant &ds) const
 {
     // trivial reject using the state mask bits
diff --git a/src/render/renderers/opengl/renderstates/renderstateset_p.h b/src/render/renderers/opengl/renderstates/renderstateset_p.h
index 29be4d2f1..c2f3a0219 100644
--- a/src/render/renderers/opengl/renderstates/renderstateset_p.h
+++ b/src/render/renderers/opengl/renderstates/renderstateset_p.h
@@ -93,8 +93,7 @@ public:
 
     QVector<StateVariant> states() const { return m_states; }
 
-    bool hasStateOfType(StateMask type) const;
-
+    bool canAddStateOfType(StateMask type) const;
 
     /**
      * @brief contains - check if this set contains a matching piece of state
@@ -102,6 +101,11 @@ public:
      * @return
      */
     bool contains(const StateVariant &ds) const;
+
+private:
+    bool hasStateOfType(StateMask type) const;
+    bool allowMultipleStatesOfType(StateMask type) const;
+
 private:
     StateMaskSet m_stateMask;
     QVector<StateVariant> m_states;