Retain root constant buffers in program bindings when applied, so tha…

…t the buffers are not deleted during commands execution

Modules/Graphics/RHI/Base/Include/Methane/Graphics/Base/Program.h

@@ -85,6 +85,7 @@ class Program
     using ShadersByType = std::array<Ptr<Rhi::IShader>, magic_enum::enum_count<Rhi::ShaderType>() - 1>;
     static ShadersByType CreateShadersByType(const Ptrs<Rhi::IShader>& shaders);
 
+    Ptrs<Rhi::IBuffer> GetRootConstantBufferPtrs(Data::Index frame_index) const;
     Data::Size GetBindingsCountAndIncrement() noexcept { return m_bindings_count++; }
 
     template<typename ShaderFuncType>

Modules/Graphics/RHI/Base/Include/Methane/Graphics/Base/ProgramBindings.h

@@ -99,6 +99,7 @@ class ProgramBindings
     void VerifyAllArgumentsAreBoundToResources() const;
     const ArgumentBindings& GetArgumentBindings() const { return m_binding_by_argument; }
     const Refs<Rhi::IResource>& GetResourceRefsByAccess(Rhi::ProgramArgumentAccessType access_type) const;
+    void RetainRootConstantBuffers() const;
 
     void ClearTransitionResourceStates();
     void RemoveTransitionResourceStates(const Rhi::IProgramArgumentBinding& argument_binding, const Rhi::IResource& resource);
@@ -128,6 +129,7 @@ class ProgramBindings
     ResourceStatesByAccess               m_transition_resource_states_by_access;
     ResourceRefsByAccess                 m_resource_refs_by_access;
     mutable Ptr<Rhi::IResourceBarriers>  m_resource_state_transition_barriers_ptr;
+    mutable Ptrs<Rhi::IBuffer>           m_applied_root_constant_buffer_ptr;
     Data::Index                          m_bindings_index = 0u; // index of this program bindings object between all program bindings of the program
 };
 

Modules/Graphics/RHI/Base/Include/Methane/Graphics/Base/RootConstantBuffer.h

@@ -92,6 +92,7 @@ class RootConstantBuffer
 
     Data::Bytes&  GetData();
     Rhi::IBuffer& GetBuffer();
+    const Ptr<Rhi::IBuffer>& GetBufferPtr() const { return m_buffer_ptr; }
 
     void SetBufferName(std::string_view buffer_name);
     std::string_view GetBufferName() { return m_buffer_name; }

Modules/Graphics/RHI/Base/Sources/Methane/Graphics/Base/Program.cpp

@@ -49,6 +49,29 @@ Program::ShadersByType Program::CreateShadersByType(const Ptrs<Rhi::IShader>& sh
     return shaders_by_type;
 }
 
+Ptrs<Rhi::IBuffer> Program::GetRootConstantBufferPtrs(Data::Index frame_index) const
+{
+    META_FUNCTION_TASK();
+    Ptrs<Rhi::IBuffer> root_constant_buffer_ptrs;
+    root_constant_buffer_ptrs.reserve(3);
+
+    if (const Ptr<Rhi::IBuffer>& buffer_ptr = m_root_constant_buffer.GetBufferPtr())
+    {
+        root_constant_buffer_ptrs.push_back(buffer_ptr);
+    }
+    if (frame_index < m_root_frame_constant_buffers.size())
+    {
+        if (const Ptr<Rhi::IBuffer>& buffer_ptr = m_root_frame_constant_buffers.at(frame_index)->GetBufferPtr())
+            root_constant_buffer_ptrs.push_back(buffer_ptr);
+    }
+    if (const Ptr<Rhi::IBuffer>& buffer_ptr = m_root_mutable_buffer.GetBufferPtr())
+    {
+        root_constant_buffer_ptrs.push_back(buffer_ptr);
+    }
+
+    return root_constant_buffer_ptrs;
+}
+
 static Rhi::ShaderTypes CreateShaderTypes(const Ptrs<Rhi::IShader>& shaders)
 {
     META_FUNCTION_TASK();

Modules/Graphics/RHI/Base/Sources/Methane/Graphics/Base/ProgramBindings.cpp

@@ -445,4 +445,14 @@ const Refs<Rhi::IResource>& ProgramBindings::GetResourceRefsByAccess(Rhi::Progra
     return m_resource_refs_by_access[magic_enum::enum_index(access_type).value()];
 }
 
+void ProgramBindings::RetainRootConstantBuffers() const
+{
+    META_FUNCTION_TASK();
+    // NOTE: We have to retain root constant buffers applied to command list and used during execution,
+    // because these buffers could be recreated in order to be resized;
+    // and will be automatically updated in all retained program binding objects.
+    auto& program = static_cast<Program&>(GetProgram());
+    m_applied_root_constant_buffer_ptr = program.GetRootConstantBufferPtrs(m_frame_index);
+}
+
 } // namespace Methane::Graphics::Base

Modules/Graphics/RHI/DirectX/Sources/Methane/Graphics/DirectX/ProgramBindings.cpp

@@ -124,12 +124,15 @@ Ptr<Rhi::IProgramBindings> ProgramBindings::CreateCopy(const BindingValueByArgum
 
 void ProgramBindings::Apply(Base::CommandList& command_list, ApplyBehaviorMask apply_behavior) const
 {
+    META_FUNCTION_TASK();
     Apply(dynamic_cast<ICommandList&>(command_list), command_list.GetProgramBindingsPtr(), apply_behavior);
 }
 
 void ProgramBindings::Apply(ICommandList& command_list, const Base::ProgramBindings* applied_program_bindings_ptr, ApplyBehaviorMask apply_behavior) const
 {
     META_FUNCTION_TASK();
+    RetainRootConstantBuffers();
+
     Rhi::ProgramArgumentAccessMask apply_access_mask;
     apply_access_mask.SetBitOn(Rhi::ProgramArgumentAccessType::Mutable);
 

Modules/Graphics/RHI/Metal/Sources/Methane/Graphics/Metal/ProgramBindings.mm

@@ -482,8 +482,9 @@ static void WriteArgumentBindingResourceIds(const ProgramArgumentBinding& arg_bi
 void ProgramBindings::Apply(Base::CommandList& command_list, ApplyBehaviorMask apply_behavior) const
 {
     META_FUNCTION_TASK();
-    const Rhi::CommandListType command_list_type = command_list.GetType();
-    switch (command_list_type)
+    RetainRootConstantBuffers();
+    switch (const Rhi::CommandListType command_list_type = command_list.GetType();
+            command_list_type)
     {
         case Rhi::CommandListType::Render:
             Apply<CommandType::Render>(static_cast<RenderCommandList&>(command_list), apply_behavior);

Modules/Graphics/RHI/Vulkan/Sources/Methane/Graphics/Vulkan/ProgramBindings.cpp

@@ -188,6 +188,7 @@ void ProgramBindings::Apply(ICommandList& command_list_vk, const Rhi::ICommandQu
 {
     META_FUNCTION_TASK();
     META_CHECK_NOT_EMPTY(m_descriptor_sets);
+    RetainRootConstantBuffers();
 
     Rhi::ProgramArgumentAccessMask apply_access;
     apply_access.SetBitOn(Rhi::ProgramArgumentAccessType::Mutable);