feat(ww3d2): add global g_renderBackend pointer and lifecycle wiring

Author: bobtista

Core/Libraries/Source/WWVegas/WW3D2/CMakeLists.txt

@@ -158,6 +158,8 @@ set(WW3D2_SRC
     proto.h
     proxy.h
     rddesc.h
+    RenderBackend.cpp
+    RenderBackend.h
     #render2d.cpp
     #render2d.h
     render2dsentence.cpp

Core/Libraries/Source/WWVegas/WW3D2/RenderBackend.cpp

@@ -0,0 +1,48 @@
+/*
+**	Command & Conquer Generals Zero Hour(tm)
+**	Copyright 2025 Electronic Arts Inc.
+**
+**	This program is free software: you can redistribute it and/or modify
+**	it under the terms of the GNU General Public License as published by
+**	the Free Software Foundation, either version 3 of the License, or
+**	(at your option) any later version.
+**
+**	This program is distributed in the hope that it will be useful,
+**	but WITHOUT ANY WARRANTY; without even the implied warranty of
+**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**	GNU General Public License for more details.
+**
+**	You should have received a copy of the GNU General Public License
+**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// TheSuperHackers @refactor bobtista 10/04/2026 Render backend global
+// owner. Holds the single g_renderBackend pointer and constructs/destroys
+// the concrete backend instance. See RENDER_BACKEND.md.
+
+#include "RenderBackend.h"
+#include "DX8Backend.h"
+
+IRenderBackend * g_renderBackend = nullptr;
+
+void Init_Render_Backend()
+{
+    if (g_renderBackend != nullptr)
+    {
+        return;
+    }
+
+    // Phase 1: the DX8 backend is the only option. Phase 2 will introduce
+    // a compile-time flag to pick between DX8, bgfx, and Diligent.
+    g_renderBackend = new DX8Backend();
+}
+
+void Shutdown_Render_Backend()
+{
+    if (g_renderBackend == nullptr)
+    {
+        return;
+    }
+    delete g_renderBackend;
+    g_renderBackend = nullptr;
+}

Core/Libraries/Source/WWVegas/WW3D2/RenderBackend.h

@@ -0,0 +1,42 @@
+/*
+**	Command & Conquer Generals Zero Hour(tm)
+**	Copyright 2025 Electronic Arts Inc.
+**
+**	This program is free software: you can redistribute it and/or modify
+**	it under the terms of the GNU General Public License as published by
+**	the Free Software Foundation, either version 3 of the License, or
+**	(at your option) any later version.
+**
+**	This program is distributed in the hope that it will be useful,
+**	but WITHOUT ANY WARRANTY; without even the implied warranty of
+**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**	GNU General Public License for more details.
+**
+**	You should have received a copy of the GNU General Public License
+**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// TheSuperHackers @refactor bobtista 10/04/2026 Backend-agnostic access point
+// for the global IRenderBackend instance. Engine-side code should include
+// this header (not IRenderBackend.h or DX8Backend.h directly) to use the
+// render backend. See RENDER_BACKEND.md.
+
+#pragma once
+
+#include "IRenderBackend.h"
+
+// The active rendering backend. Set by Init_Render_Backend() during
+// WW3D device initialization and cleared by Shutdown_Render_Backend()
+// during device teardown. Never null between those two calls.
+extern IRenderBackend * g_renderBackend;
+
+// Create the render backend. Called by DX8Wrapper::Do_Onetime_Device_Dependent_Inits
+// after the D3D device has been successfully created.
+//
+// Phase 1 always creates a DX8Backend. Phase 2 will add a compile-time
+// option to select between DX8Backend, BgfxBackend, and DiligentBackend.
+void Init_Render_Backend();
+
+// Destroy the render backend. Called by DX8Wrapper::Do_Onetime_Device_Dependent_Shutdowns
+// before the D3D device is released.
+void Shutdown_Render_Backend();

Core/Libraries/Source/WWVegas/WW3D2/dx8wrapper.cpp

@@ -56,6 +56,7 @@
 #include "dx8vertexbuffer.h"
 #include "dx8indexbuffer.h"
 #include "dx8renderer.h"
+#include "RenderBackend.h"
 #include "ww3d.h"
 #include "camera.h"
 #include "wwstring.h"
@@ -387,6 +388,11 @@ void DX8Wrapper::Do_Onetime_Device_Dependent_Inits()
 	TextureLoader::Init();
 
 	Set_Default_Global_Render_States();
+
+	// TheSuperHackers @refactor bobtista 10/04/2026 Construct the global
+	// IRenderBackend instance now that the D3D device is ready. See
+	// Core/Libraries/Source/WWVegas/WW3D2/RENDER_BACKEND.md.
+	Init_Render_Backend();
 }
 
 inline DWORD F2DW(float f) { return *((unsigned*)&f); }
@@ -447,6 +453,11 @@ void DX8Wrapper::Invalidate_Cached_Render_States()
 
 void DX8Wrapper::Do_Onetime_Device_Dependent_Shutdowns()
 {
+	// TheSuperHackers @refactor bobtista 10/04/2026 Tear down the render
+	// backend before the D3D device is released so any backend-owned
+	// resources get released first. See RENDER_BACKEND.md.
+	Shutdown_Render_Backend();
+
 	/*
 	** Shutdown ww3d systems
 	*/