Ignore RenderCommand for current frame, if shader not loaded yet

Renderer::m_shaderGathererJob might not have finished yet, so the shader
wasn't marked as dirty yet, so it wasn't loaded in
Renderer::updateGLResources(). Next frame everything will be alright.

Task-number: QTBUG-55093
Change-Id: Ia60ed1dff4cb0495efbd7f70f87d227007ef560d
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

3 files changed, 11 insertions, 5 deletions

diff --git a/src/render/backend/renderer.cpp b/src/render/backend/renderer.cpp
index cf7e53256..811379336 100644
--- a/src/render/backend/renderer.cpp
+++ b/src/render/backend/renderer.cpp
@@ -1401,7 +1401,10 @@ bool Renderer::executeCommandsSubmission(const RenderView *rv)
             {
                 Profiling::GLTimeRecorder recorder(Profiling::ShaderUpdate);
                 //// We activate the shader here
-                m_graphicsContext->activateShader(command->m_shaderDna);
+                if (!m_graphicsContext->activateShader(command->m_shaderDna)) {
+                    allCommandsIssued = false;
+                    continue;
+                }
             }
 
             {
diff --git a/src/render/graphicshelpers/graphicscontext.cpp b/src/render/graphicshelpers/graphicscontext.cpp
index 21a45dd9b..919ae5bd6 100644
--- a/src/render/graphicshelpers/graphicscontext.cpp
+++ b/src/render/graphicshelpers/graphicscontext.cpp
@@ -509,9 +509,12 @@ void GraphicsContext::loadShader(Shader *shader)
 }
 
 // Called only from RenderThread
-void GraphicsContext::activateShader(ProgramDNA shaderDNA)
+bool GraphicsContext::activateShader(ProgramDNA shaderDNA)
 {
     if (shaderDNA != m_activeShaderDNA) {
+        // Ensure material uniforms are re-applied
+        m_material = nullptr;
+
         m_activeShader = m_shaderCache.getShaderProgramForDNA(shaderDNA);
         if (Q_LIKELY(m_activeShader != nullptr)) {
             m_activeShader->bind();
@@ -520,10 +523,10 @@ void GraphicsContext::activateShader(ProgramDNA shaderDNA)
             m_glHelper->useProgram(0);
             qWarning() << "No shader program found for DNA";
             m_activeShaderDNA = 0;
+            return false;
         }
-        // Ensure material uniforms are re-applied
-        m_material = nullptr;
     }
+    return true;
 }
 
 void GraphicsContext::removeShaderProgramReference(Shader *shaderNode)
diff --git a/src/render/graphicshelpers/graphicscontext_p.h b/src/render/graphicshelpers/graphicscontext_p.h
index 9f7a0f972..8067bb8b8 100644
--- a/src/render/graphicshelpers/graphicscontext_p.h
+++ b/src/render/graphicshelpers/graphicscontext_p.h
@@ -130,7 +130,7 @@ public:
 
     QOpenGLShaderProgram *createShaderProgram(Shader *shaderNode);
     void loadShader(Shader* shader);
-    void activateShader(ProgramDNA shaderDNA);
+    bool activateShader(ProgramDNA shaderDNA);
     void removeShaderProgramReference(Shader *shaderNode);
 
     GLuint activeFBO() const { return m_activeFBO; }