Pass changes WIP: standardized usage of new pass initialization functions

Gems/Atom/RPI/Code/Source/RPI.Public/Pass/FullscreenTrianglePass.cpp

@@ -64,6 +64,8 @@ namespace AZ
 
         void FullscreenTrianglePass::LoadShader()
         {
+            AZ_Assert(GetPassState() != PassState::Rendering, "FullscreenTrianglePass - Reloading shader during Rendering phase!");
+
             // Load FullscreenTrianglePassData
             const FullscreenTrianglePassData* passData = PassUtils::GetPassData<FullscreenTrianglePassData>(m_passDescriptor);
             if (passData == nullptr)
@@ -121,14 +123,16 @@ namespace AZ
             // Store stencil reference value for the draw call
             m_stencilRef = passData->m_stencilRef;
 
-            m_flags.m_initialized = false;
+            QueueForInitialization();
 
             ShaderReloadNotificationBus::Handler::BusDisconnect();
             ShaderReloadNotificationBus::Handler::BusConnect(shaderAsset.GetId());
         }
 
-        void FullscreenTrianglePass::Init()
+        void FullscreenTrianglePass::InitializeInternal()
         {
+            RenderPass::InitializeInternal();
+
             // This draw item purposefully does not reference any geometry buffers.
             // Instead it's expected that the extended class uses a vertex shader 
             // that generates a full-screen triangle completely from vertex ids.
@@ -155,17 +159,10 @@ namespace AZ
             m_item.m_arguments = RHI::DrawArguments(draw);
             m_item.m_pipelineState = m_shader->AcquirePipelineState(pipelineStateDescriptor);
             m_item.m_stencilRef = m_stencilRef;
-
-            m_flags.m_initialized = true;
         }
 
         void FullscreenTrianglePass::FrameBeginInternal(FramePrepareParams params)
         {
-            if (!m_flags.m_initialized)
-            {
-                Init();
-            }
-
             const PassAttachment* outputAttachment = nullptr;
             
             if (GetOutputCount() > 0)
@@ -225,11 +222,6 @@ namespace AZ
 
             commandList->Submit(m_item);
         }
-
-        void FullscreenTrianglePass::Invalidate()
-        {
-            m_flags.m_initialized = false;
-        }
         
     }   // namespace RPI
 }   // namespace AZ