Provide ImGui implementation for SDL

Add header

Add newline at end of file

Fix for format

Author: James Johnson

Imgui/CMakeLists.txt

@@ -6,6 +6,7 @@ set(SOURCE
     src/ImGuiDiligentRenderer.cpp
     src/ImGuiImplDiligent.cpp
     src/ImGuiUtils.cpp
+    src/ImGuiImplSDL.cpp
 )
 
 set(IMGUIZMO_QUAT_SOURCE
@@ -17,6 +18,7 @@ set(INTERFACE
     interface/ImGuiDiligentRenderer.hpp
     interface/ImGuiImplDiligent.hpp
     interface/ImGuiUtils.hpp
+    interface/ImGuiImplSDL.hpp
 )
 
 if(PLATFORM_WIN32)

Imgui/interface/ImGuiImplSDL.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "ImGuiImplDiligent.hpp"
+
+extern "C" struct SDL_Window;
+extern "C" union SDL_Event;
+
+namespace Diligent
+{
+class ImGuiImplSDL final : public ImGuiImplDiligent
+{
+public:
+    static std::unique_ptr<ImGuiImplSDL>
+    Create(const ImGuiDiligentCreateInfo& CI, SDL_Window* pWindow);
+
+    ImGuiImplSDL(const ImGuiDiligentCreateInfo& CI, SDL_Window* pWindow);
+    ~ImGuiImplSDL();
+
+    // clang-format off
+    ImGuiImplSDL             (const ImGuiImplSDL&)  = delete;
+    ImGuiImplSDL             (      ImGuiImplSDL&&) = delete;
+    ImGuiImplSDL& operator = (const ImGuiImplSDL&)  = delete;
+    ImGuiImplSDL& operator = (      ImGuiImplSDL&&) = delete;
+    // clang-format on
+
+    virtual void NewFrame(Uint32            RenderSurfaceWidth,
+                          Uint32            RenderSurfaceHeight,
+                          SURFACE_TRANSFORM SurfacePreTransform) override final;
+    virtual void Render(IDeviceContext* pCtx) override final;
+    bool         HandleSDLEvent(const SDL_Event* ev);
+};
+} // namespace Diligent

Imgui/src/ImGuiImplSDL.cpp

@@ -0,0 +1,97 @@
+/*
+ *  Copyright 2025 Diligent Graphics LLC
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  In no event and under no legal theory, whether in tort (including negligence),
+ *  contract, or otherwise, unless required by applicable law (such as deliberate
+ *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
+ *  liable for any damages, including any direct, indirect, special, incidental,
+ *  or consequential damages of any character arising as a result of this License or
+ *  out of the use or inability to use the software (including but not limited to damages
+ *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and
+ *  all other commercial damages or losses), even if such Contributor has been advised
+ *  of the possibility of such damages.
+ */
+
+#include "ImGuiImplSDL.hpp"
+
+#include "Errors.hpp"
+#include "RenderDevice.h"
+#include "backends/imgui_impl_sdl.h"
+
+#include <memory>
+
+namespace Diligent
+{
+
+std::unique_ptr<ImGuiImplSDL>
+ImGuiImplSDL::Create(const ImGuiDiligentCreateInfo& CI, SDL_Window* pWindow)
+{
+    return std::make_unique<ImGuiImplSDL>(CI, pWindow);
+}
+
+ImGuiImplSDL::ImGuiImplSDL(const ImGuiDiligentCreateInfo& CI,
+                           SDL_Window*                    pWindow) :
+    ImGuiImplDiligent(CI)
+{
+    switch (CI.pDevice->GetDeviceInfo().Type)
+    {
+        case RENDER_DEVICE_TYPE_UNDEFINED:
+            LOG_ERROR_AND_THROW("Undefined device type");
+            break;
+        case RENDER_DEVICE_TYPE_D3D11:
+        case RENDER_DEVICE_TYPE_D3D12:
+            ImGui_ImplSDL2_InitForD3D(pWindow);
+            break;
+        case RENDER_DEVICE_TYPE_GL:
+        case RENDER_DEVICE_TYPE_GLES:
+            ImGui_ImplSDL2_InitForOpenGL(pWindow, nullptr);
+            break;
+        case RENDER_DEVICE_TYPE_VULKAN:
+            ImGui_ImplSDL2_InitForVulkan(pWindow);
+            break;
+        case RENDER_DEVICE_TYPE_METAL:
+            ImGui_ImplSDL2_InitForMetal(pWindow);
+            break;
+        case RENDER_DEVICE_TYPE_WEBGPU:
+            LOG_ERROR_AND_THROW("WebGPU not supported");
+            break;
+        case RENDER_DEVICE_TYPE_COUNT:
+            LOG_ERROR_AND_THROW("Unsupported device type");
+            break;
+    }
+}
+
+ImGuiImplSDL::~ImGuiImplSDL() { ImGui_ImplSDL2_Shutdown(); }
+
+void ImGuiImplSDL::NewFrame(Uint32            RenderSurfaceWidth,
+                            Uint32            RenderSurfaceHeight,
+                            SURFACE_TRANSFORM SurfacePreTransform)
+{
+    ImGui_ImplSDL2_NewFrame();
+    ImGuiImplDiligent::NewFrame(RenderSurfaceWidth, RenderSurfaceHeight,
+                                SurfacePreTransform);
+}
+
+void ImGuiImplSDL::Render(IDeviceContext* pCtx)
+{
+    ImGuiImplDiligent::Render(pCtx);
+}
+
+bool ImGuiImplSDL::HandleSDLEvent(const SDL_Event* ev)
+{
+    return ImGui_ImplSDL2_ProcessEvent(ev);
+}
+
+} // namespace Diligent