Skip RenderView which don't need to be submitted

This is when a particular set of filters/layers ... result
in a renderview that has no render commands to submit.
Trying to submit such renderview is just a waste of time.

RenderViews that have no commands but do buffer download,
back buffer clearing, setting fences .... are still submitted
even if there are no commands to render.

Change-Id: I4f66334b9b2170249c7c7aae1024ebccc8427750
Reviewed-by: Mike Krus <mike.krus@kdab.com>

3 files changed, 28 insertions, 0 deletions

diff --git a/src/plugins/renderers/opengl/renderer/renderer.cpp b/src/plugins/renderers/opengl/renderer/renderer.cpp
index 79eca16fa..e385a264e 100644
--- a/src/plugins/renderers/opengl/renderer/renderer.cpp
+++ b/src/plugins/renderers/opengl/renderer/renderer.cpp
@@ -1579,6 +1579,9 @@ Renderer::ViewSubmissionResultData Renderer::submitRenderViews(const QVector<Ren
         // If the RenderView has a RenderStateSet defined
         const RenderView *renderView = renderViews.at(i);
 
+        if (renderView->shouldSkipSubmission())
+            continue;
+
         // Check if using the same surface as the previous RenderView.
         // If not, we have to free up the context from the previous surface
         // and make the context current on the new surface
diff --git a/src/plugins/renderers/opengl/renderer/renderview.cpp b/src/plugins/renderers/opengl/renderer/renderview.cpp
index f18f1a06a..47f4beffd 100644
--- a/src/plugins/renderers/opengl/renderer/renderview.cpp
+++ b/src/plugins/renderers/opengl/renderer/renderview.cpp
@@ -1213,6 +1213,29 @@ void RenderView::setHasBlitFramebufferInfo(bool hasBlitFramebufferInfo)
     m_hasBlitFramebufferInfo = hasBlitFramebufferInfo;
 }
 
+bool RenderView::shouldSkipSubmission() const
+{
+    if (!m_commands.empty())
+        return false;
+
+    if (m_hasBlitFramebufferInfo)
+        return false;
+
+    if (m_isDownloadBuffersEnable)
+        return false;
+
+    if (m_showDebugOverlay)
+        return false;
+
+    if (!m_waitFences.empty() || !m_insertFenceIds.empty())
+        return false;
+
+    if (m_clearBuffer != QClearBuffers::None)
+        return false;
+
+    return true;
+}
+
 BlitFramebufferInfo RenderView::blitFrameBufferInfo() const
 {
     return m_blitFrameBufferInfo;
diff --git a/src/plugins/renderers/opengl/renderer/renderview_p.h b/src/plugins/renderers/opengl/renderer/renderview_p.h
index a835c17f0..c9e69d507 100644
--- a/src/plugins/renderers/opengl/renderer/renderview_p.h
+++ b/src/plugins/renderers/opengl/renderer/renderview_p.h
@@ -290,6 +290,8 @@ public:
     bool hasBlitFramebufferInfo() const;
     void setHasBlitFramebufferInfo(bool hasBlitFramebufferInfo);
 
+    bool shouldSkipSubmission() const;
+
 private:
     void setShaderAndUniforms(RenderCommand *command,
                               ParameterInfoList &parameters,