Refacotr buildRenderStateSet to a free function

Also added some todo's to improve efficiency.

Change-Id: Ib982042fee4bd3e3928381456df806babf26734d
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

4 files changed, 88 insertions, 76 deletions

diff --git a/src/render/backend/jobs/renderviewjobutils.cpp b/src/render/backend/jobs/renderviewjobutils.cpp
index 35f4ccc70..1a4f3bf06 100644
--- a/src/render/backend/jobs/renderviewjobutils.cpp
+++ b/src/render/backend/jobs/renderviewjobutils.cpp
@@ -41,7 +41,18 @@
 
 #include "renderviewjobutils_p.h"
 
+#include <Qt3DRenderer/qalphacoverage.h>
+#include <Qt3DRenderer/qalphatest.h>
+#include <Qt3DRenderer/qblendequation.h>
+#include <Qt3DRenderer/qblendstate.h>
+#include <Qt3DRenderer/qcullface.h>
+#include <Qt3DRenderer/qdepthmask.h>
+#include <Qt3DRenderer/qdepthtest.h>
+#include <Qt3DRenderer/qdithering.h>
+#include <Qt3DRenderer/qfrontface.h>
 #include <Qt3DRenderer/qopenglfilter.h>
+#include <Qt3DRenderer/qscissortest.h>
+#include <Qt3DRenderer/qstenciltest.h>
 #include <Qt3DRenderer/sphere.h>
 
 #include <Qt3DRenderer/private/cameraselectornode_p.h>
@@ -50,12 +61,15 @@
 #include <Qt3DRenderer/private/managers_p.h>
 #include <Qt3DRenderer/private/rendereffect_p.h>
 #include <Qt3DRenderer/private/renderpassfilternode_p.h>
+#include <Qt3DRenderer/private/renderstate_p.h>
 #include <Qt3DRenderer/private/rendertargetselectornode_p.h>
 #include <Qt3DRenderer/private/renderview_p.h>
 #include <Qt3DRenderer/private/sortmethod_p.h>
 #include <Qt3DRenderer/private/techniquefilternode_p.h>
 #include <Qt3DRenderer/private/viewportnode_p.h>
 
+// TODO: Rename this include to something more descriptive
+#include <Qt3DRenderer/private/blendstate_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -336,6 +350,69 @@ QHash<QString, QVariant> parametersFromMaterialEffectTechnique(ParameterManager
     return params;
 }
 
+RenderStateSet *buildRenderStateSet(RenderRenderPass *pass, QFrameAllocator *allocator)
+{
+    if (!pass || pass->renderStates().isEmpty())
+        return Q_NULLPTR;
+
+    RenderStateSet *stateSet = allocator->allocate<RenderStateSet>();
+
+    // TODO: Don't use QObject subclasses as backend storage and replace this if
+    // cascade with a switch
+    Q_FOREACH (QRenderState *renderState, pass->renderStates()) {
+        if (qobject_cast<QAlphaTest *>(renderState) != Q_NULLPTR) {
+            QAlphaTest *alphaTest = qobject_cast<QAlphaTest *>(renderState);
+            stateSet->addState(AlphaFunc::getOrCreate(alphaTest->func(), alphaTest->clamp()));
+        }
+        else if (qobject_cast<QBlendEquation *>(renderState) != Q_NULLPTR) {
+            QBlendEquation *blendEquation = qobject_cast<QBlendEquation *>(renderState);
+            stateSet->addState(BlendEquation::getOrCreate(blendEquation->mode()));
+        }
+        else if (qobject_cast<QBlendState *>(renderState) != Q_NULLPTR) {
+            QBlendState *blendState = qobject_cast<QBlendState *>(renderState);
+            // TO DO : Handle Alpha here as weel
+            stateSet->addState(BlendState::getOrCreate(blendState->srcRGB(), blendState->dstRGB()));
+        }
+        else if (qobject_cast<QCullFace *>(renderState) != Q_NULLPTR) {
+            QCullFace *cullFace = qobject_cast<QCullFace *>(renderState);
+            stateSet->addState(CullFace::getOrCreate(cullFace->mode()));
+        }
+        else if (qobject_cast<QDepthMask *>(renderState) != Q_NULLPTR) {
+            QDepthMask *depthMask = qobject_cast<QDepthMask *>(renderState);
+            stateSet->addState(DepthMask::getOrCreate(depthMask->mask()));
+        }
+        else if (qobject_cast<QDepthTest *>(renderState) != Q_NULLPTR) {
+            QDepthTest *depthTest = qobject_cast<QDepthTest *>(renderState);
+            stateSet->addState(DepthTest::getOrCreate(depthTest->func()));
+        }
+        else if (qobject_cast<QDithering *>(renderState) != Q_NULLPTR) {
+            stateSet->addState(Dithering::getOrCreate());
+        }
+        else if (qobject_cast<QFrontFace *>(renderState) != Q_NULLPTR) {
+            QFrontFace *frontFace = qobject_cast<QFrontFace *>(renderState);
+            stateSet->addState(FrontFace::getOrCreate(frontFace->direction()));
+        }
+        else if (qobject_cast<QScissorTest *>(renderState) != Q_NULLPTR) {
+            QScissorTest *scissorTest = qobject_cast<QScissorTest *>(renderState);
+            stateSet->addState(ScissorTest::getOrCreate(scissorTest->left(),
+                                                        scissorTest->bottom(),
+                                                        scissorTest->width(),
+                                                        scissorTest->height()));
+        }
+        else if (qobject_cast<QStencilTest *>(renderState) != Q_NULLPTR) {
+            QStencilTest *stencilTest = qobject_cast<QStencilTest *>(renderState);
+            stateSet->addState(StencilTest::getOrCreate(stencilTest->mask(),
+                                                        stencilTest->func(),
+                                                        stencilTest->faceMode()));
+        }
+        else if (qobject_cast<QAlphaCoverage *>(renderState) != Q_NULLPTR) {
+            stateSet->addState(AlphaCoverage::getOrCreate());
+        }
+    }
+
+    return stateSet;
+}
+
 } // namespace Render
 } // namespace Qt3D
 
diff --git a/src/render/backend/jobs/renderviewjobutils_p.h b/src/render/backend/jobs/renderviewjobutils_p.h
index 762d47fb3..2889b6fde 100644
--- a/src/render/backend/jobs/renderviewjobutils_p.h
+++ b/src/render/backend/jobs/renderviewjobutils_p.h
@@ -50,6 +50,9 @@
 QT_BEGIN_NAMESPACE
 
 namespace Qt3D {
+
+class QFrameAllocator;
+
 namespace Render {
 
 class FrameGraphNode;
@@ -58,6 +61,7 @@ class RenderEffect;
 class RenderEntity;
 class RenderMaterial;
 class RenderRenderPass;
+class RenderStateSet;
 class RenderTechnique;
 class RenderView;
 class Renderer;
@@ -80,6 +84,9 @@ Q_AUTOTEST_EXPORT QHash<QString, QVariant> parametersFromMaterialEffectTechnique
                                                                                  RenderEffect *effect,
                                                                                  RenderTechnique *technique);
 
+Q_AUTOTEST_EXPORT RenderStateSet *buildRenderStateSet(RenderRenderPass *pass,
+                                                      QFrameAllocator *allocator);
+
 } // namespace Render
 } // namespace Qt3D
 
diff --git a/src/render/backend/renderview.cpp b/src/render/backend/renderview.cpp
index 0c444fabc..990ffc8e9 100644
--- a/src/render/backend/renderview.cpp
+++ b/src/render/backend/renderview.cpp
@@ -62,25 +62,14 @@
 #include <Qt3DRenderer/private/renderlight_p.h>
 #include <Qt3DRenderer/private/renderpassfilternode_p.h>
 #include <Qt3DRenderer/private/renderrenderpass_p.h>
+#include <Qt3DRenderer/private/renderstate_p.h>
 #include <Qt3DRenderer/private/techniquefilternode_p.h>
 #include <Qt3DRenderer/private/viewportnode_p.h>
 
 #include <Qt3DRenderer/qparametermapping.h>
-#include <Qt3DRenderer/qalphatest.h>
-#include <Qt3DRenderer/qblendequation.h>
-#include <Qt3DRenderer/qblendstate.h>
-#include <Qt3DRenderer/qcullface.h>
-#include <Qt3DRenderer/qdepthmask.h>
-#include <Qt3DRenderer/qdepthtest.h>
-#include <Qt3DRenderer/qdithering.h>
-#include <Qt3DRenderer/qfrontface.h>
-#include <Qt3DRenderer/qscissortest.h>
-#include <Qt3DRenderer/qstenciltest.h>
-#include <Qt3DRenderer/qalphacoverage.h>
 
 // TODO: Move out once this is all refactored
 #include <Qt3DRenderer/private/renderviewjobutils_p.h>
-#include <Qt3DRenderer/private/blendstate_p.h>
 
 #include <Qt3DCore/qentity.h>
 
@@ -360,7 +349,9 @@ void RenderView::buildRenderCommands(RenderEntity *node)
                     command->m_depth = m_data->m_eyePos.distanceToPoint(node->worldBoundingVolume()->center());
                     command->m_meshData = mesh->meshData();
                     command->m_instancesCount = 0;
-                    command->m_stateSet = buildRenderStateSet(pass);
+
+                    // TODO: Build the state set for a render pass only once per-pass. Not once per rendercommand and pass.
+                    command->m_stateSet = buildRenderStateSet(pass, m_allocator);
                     if (command->m_stateSet != Q_NULLPTR)
                         command->m_changeCost = m_renderer->defaultRenderState()->changeCost(command->m_stateSet);
                     setShaderAndUniforms(command, pass, parameters, *(node->worldTransform()));
@@ -381,68 +372,6 @@ const AttachmentPack &RenderView::attachmentPack() const
     return m_attachmentPack;
 }
 
-// Build a RenderStateSet from the QRenderState stored in the RenderRenderPass
-RenderStateSet *RenderView::buildRenderStateSet(RenderRenderPass *pass)
-{
-    if (pass != Q_NULLPTR && pass->renderStates().count() > 0) {
-        RenderStateSet *stateSet = m_allocator->allocate<RenderStateSet>();
-
-        Q_FOREACH (QRenderState *renderState, pass->renderStates()) {
-            if (qobject_cast<QAlphaTest *>(renderState) != Q_NULLPTR) {
-                QAlphaTest *alphaTest = qobject_cast<QAlphaTest *>(renderState);
-                stateSet->addState(AlphaFunc::getOrCreate(alphaTest->func(), alphaTest->clamp()));
-            }
-            else if (qobject_cast<QBlendEquation *>(renderState) != Q_NULLPTR) {
-                QBlendEquation *blendEquation = qobject_cast<QBlendEquation *>(renderState);
-                stateSet->addState(BlendEquation::getOrCreate(blendEquation->mode()));
-            }
-            else if (qobject_cast<QBlendState *>(renderState) != Q_NULLPTR) {
-                QBlendState *blendState = qobject_cast<QBlendState *>(renderState);
-                // TO DO : Handle Alpha here as weel
-                stateSet->addState(BlendState::getOrCreate(blendState->srcRGB(), blendState->dstRGB()));
-            }
-            else if (qobject_cast<QCullFace *>(renderState) != Q_NULLPTR) {
-                QCullFace *cullFace = qobject_cast<QCullFace *>(renderState);
-                stateSet->addState(CullFace::getOrCreate(cullFace->mode()));
-            }
-            else if (qobject_cast<QDepthMask *>(renderState) != Q_NULLPTR) {
-                QDepthMask *depthMask = qobject_cast<QDepthMask *>(renderState);
-                stateSet->addState(DepthMask::getOrCreate(depthMask->mask()));
-            }
-            else if (qobject_cast<QDepthTest *>(renderState) != Q_NULLPTR) {
-                QDepthTest *depthTest = qobject_cast<QDepthTest *>(renderState);
-                stateSet->addState(DepthTest::getOrCreate(depthTest->func()));
-            }
-            else if (qobject_cast<QDithering *>(renderState) != Q_NULLPTR) {
-                stateSet->addState(Dithering::getOrCreate());
-            }
-            else if (qobject_cast<QFrontFace *>(renderState) != Q_NULLPTR) {
-                QFrontFace *frontFace = qobject_cast<QFrontFace *>(renderState);
-                stateSet->addState(FrontFace::getOrCreate(frontFace->direction()));
-            }
-            else if (qobject_cast<QScissorTest *>(renderState) != Q_NULLPTR) {
-                QScissorTest *scissorTest = qobject_cast<QScissorTest *>(renderState);
-                stateSet->addState(ScissorTest::getOrCreate(scissorTest->left(),
-                                                            scissorTest->bottom(),
-                                                            scissorTest->width(),
-                                                            scissorTest->height()));
-            }
-            else if (qobject_cast<QStencilTest *>(renderState) != Q_NULLPTR) {
-                QStencilTest *stencilTest = qobject_cast<QStencilTest *>(renderState);
-                stateSet->addState(StencilTest::getOrCreate(stencilTest->mask(),
-                                                            stencilTest->func(),
-                                                            stencilTest->faceMode()));
-            }
-            else if (qobject_cast<QAlphaCoverage *>(renderState) != Q_NULLPTR) {
-                stateSet->addState(AlphaCoverage::getOrCreate());
-            }
-        }
-
-        return stateSet;
-    }
-    return Q_NULLPTR;
-}
-
 void RenderView::setUniformValue(QUniformPack &uniformPack, const QString &name, const QVariant &value)
 {
     QTexture *tex = Q_NULLPTR;
diff --git a/src/render/backend/renderview_p.h b/src/render/backend/renderview_p.h
index a2ce96a5b..925a2f7c0 100644
--- a/src/render/backend/renderview_p.h
+++ b/src/render/backend/renderview_p.h
@@ -192,7 +192,6 @@ public:
 
 private:
     void setShaderAndUniforms(RenderCommand *command, RenderRenderPass *pass, QHash<QString, QVariant> &parameters, const QMatrix4x4 &worldTransform);
-    RenderStateSet *buildRenderStateSet(RenderRenderPass *pass);
 
     Renderer *m_renderer;
     QFrameAllocator *m_allocator;