Merge pull request #22033 from hrydgard/sdl-headless-vulkan

Headless SDL: Add support for Vulkan rendering

CMakeLists.txt

@@ -1049,6 +1049,7 @@ else()
 		SDL/SDLJoystick.h
 		SDL/SDLJoystick.cpp
 		SDL/SDLMain.cpp
+		SDL/SDLUtil.cpp
 		SDL/SDLGLGraphicsContext.cpp
 	)
 	if(SDL_TTF_LIB_TARGET)
@@ -1329,13 +1330,22 @@ if(HEADLESS)
 		headless/Headless.cpp
 		headless/Compare.cpp
 		headless/Compare.h
-		headless/SDLHeadlessGLGraphicsContext.cpp
-		headless/SDLHeadlessGLGraphicsContext.h
 	)
+	if(SDL_LIB_TARGET)
+		list(APPEND HeadlessSource
+			headless/SDLHeadlessGLGraphicsContext.cpp
+			headless/SDLHeadlessGLGraphicsContext.h
+			# TODO: Break these out into a library instead of cross linking like this.
+			SDL/SDLUtil.cpp
+			SDL/SDLUtil.h
+		)
+	endif()
 	if(APPLE)
 		list(APPEND HeadlessSource
 			Common/Render/Text/draw_text_cocoa.mm
 			Common/Render/Text/draw_text_cocoa.h
+			SDL/SDLCocoaMetalLayer.h
+			SDL/SDLCocoaMetalLayer.mm
 		)
 		set_source_files_properties(Common/Render/Text/draw_text_cocoa.mm
 			PROPERTIES COMPILE_FLAGS -fobjc-arc)

Common/GPU/Vulkan/VulkanContext.cpp

@@ -91,6 +91,23 @@ const char *VulkanImageLayoutToString(VkImageLayout imageLayout) {
 	}
 }
 
+const char *WindowSystemToString(WindowSystem winsys) {
+	switch (winsys) {
+	case WINDOWSYSTEM_UNINITIALIZED: return "UNINITIALIZED";
+	case WINDOWSYSTEM_WIN32: return "WIN32";
+	case WINDOWSYSTEM_ANDROID: return "ANDROID";
+	case WINDOWSYSTEM_METAL_EXT: return "METAL_EXT";
+	case WINDOWSYSTEM_XLIB: return "XLIB";
+	case WINDOWSYSTEM_XCB: return "XCB";
+	case WINDOWSYSTEM_WAYLAND: return "WAYLAND";
+	case WINDOWSYSTEM_DISPLAY: return "DISPLAY";
+	case WINDOWSYSTEM_SDL: return "SDL";
+	case WINDOWSYSTEM_NONE: return "NONE";
+	default:
+		return "UNKNOWN";
+	}
+}
+
 VulkanContext::VulkanContext() {
 	// Do nothing here.
 }
@@ -970,9 +987,9 @@ VkResult VulkanContext::ReinitSurface() {
 		surface_ = VK_NULL_HANDLE;
 	}
 
-	INFO_LOG(Log::G3D, "Creating Vulkan surface for window (data1=%p data2=%p)", winsysData1_, winsysData2_);
+	INFO_LOG(Log::G3D, "Creating Vulkan surface for window (winsys=%s data1=%p data2=%p)", WindowSystemToString(winsys_), winsysData1_, winsysData2_);
 
-	VkResult retval = VK_SUCCESS;
+		VkResult retval = VK_SUCCESS;
 
 	switch (winsys_) {
 #ifdef _WIN32
@@ -1233,7 +1250,7 @@ VkResult VulkanContext::ReinitSurface() {
 #endif
 
 	default:
-		_assert_msg_(false, "Vulkan support for chosen window system not implemented");
+		_assert_msg_(false, "Vulkan support for chosen window system (%s) not implemented", WindowSystemToString(winsys_));
 		return VK_ERROR_INITIALIZATION_FAILED;
 	}
 

SDL/SDLMain.cpp

@@ -67,6 +67,7 @@ SDLJoystick *joystick = NULL;
 #include "Core/Config.h"
 #include "Core/ConfigValues.h"
 #include "SDLGLGraphicsContext.h"
+#include "SDLUtil.h"
 
 #include <SDL3/SDL_vulkan.h>
 
@@ -1726,58 +1727,6 @@ void UpdateSDLCursor() {
 #endif
 }
 
-bool DetermineVulkanWindowSystem(SDL_Window *window, WindowSystem *windowSystem, void **data1, void **data2, std::string *errorMessage) {
-	_dbg_assert_(window);
-	SDL_PropertiesID windowProps = SDL_GetWindowProperties(window);
-	void *x11Display = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_X11_DISPLAY_POINTER, nullptr);
-	if (x11Display != nullptr) {
-		intptr_t x11Window = (intptr_t)SDL_GetNumberProperty(windowProps, SDL_PROP_WINDOW_X11_WINDOW_NUMBER, 0);
-#if defined(VK_USE_PLATFORM_XLIB_KHR)
-		*windowSystem = WINDOWSYSTEM_XLIB;
-		*data1 = x11Display;
-		*data2 = (void *)x11Window;
-#elif defined(VK_USE_PLATFORM_XCB_KHR)
-		*windowSystem = WINDOWSYSTEM_XCB;
-		*data1 = (void *)XGetXCBConnection((Display *)x11Display);
-		*data2 = (void *)x11Window;
-#endif
-		return true;
-	}
-#if defined(VK_USE_PLATFORM_WAYLAND_KHR)
-	void *waylandDisplay = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_WAYLAND_DISPLAY_POINTER, nullptr);
-	void *waylandSurface = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_WAYLAND_SURFACE_POINTER, nullptr);
-	if (waylandDisplay != nullptr && waylandSurface != nullptr) {
-		*windowSystem = WINDOWSYSTEM_WAYLAND;
-		*data1 = waylandDisplay;
-		*data2 = waylandSurface;
-		return true;
-	}
-#elif defined(VK_USE_PLATFORM_METAL_EXT)
-#if PPSSPP_PLATFORM(MAC)
-	void *cocoaWindow = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_COCOA_WINDOW_POINTER, nullptr);
-	if (cocoaWindow != nullptr) {
-		*windowSystem = WINDOWSYSTEM_METAL_EXT;
-		*data1 = makeWindowMetalCompatible(cocoaWindow);
-		*data2 = nullptr;
-		return true;
-	}
-#else
-	// This path is currently not used as we do not use SDL on iOS, but it is here for completeness.
-	void *uikitWindow = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_UIKIT_WINDOW_POINTER, nullptr);
-	if (uikitWindow != nullptr) {
-		*windowSystem = WINDOWSYSTEM_METAL_EXT;
-		*data1 = makeWindowMetalCompatible(uikitWindow);
-		*data2 = nullptr;
-		return true;
-	}
-#endif
-#endif  // VK_USE_PLATFORM_METAL_EXT
-	if (errorMessage) {
-		*errorMessage = "Unable to determine Vulkan window system from SDL3 window properties";
-	}
-	return false;
-}
-
 #ifdef _WIN32
 #undef main
 #endif
@@ -2007,19 +1956,16 @@ int main(int argc, char *argv[]) {
 	}
 
 	SDL_Window *window = nullptr;
+	WindowDesc windowDesc;
 	auto initializeBackend = [&](GPUBackend backend, GraphicsContext **graphicsContext, std::string *errorMessage) -> bool {
-		// Surface init params.
-		WindowSystem windowSystem = WINDOWSYSTEM_NONE;
-		void *data1 = nullptr;
-		void *data2 = nullptr;
-
 		GraphicsContext *ctx = nullptr;
 		if (backend == GPUBackend::OPENGL) {
 			SDL_GLContext glContext = nullptr;
 			window = CreateSDLGLWindowAndContext(x, y, w, h, mode, cmdLineOptions.force_gl_version, &glContext, errorMessage);
 
-			data1 = (void *)window;
-			data2 = (void *)glContext;
+			windowDesc.winsys = WINDOWSYSTEM_SDL;
+			windowDesc.data1 = (void *)window;
+			windowDesc.data2 = (void *)glContext;
 
 			ctx = new SDLGLGraphicsContext();
 		} else {
@@ -2038,7 +1984,7 @@ int main(int argc, char *argv[]) {
 			}
 
 			// Overwrite the surface init params with what we need for Vulkan..
-			if (!DetermineVulkanWindowSystem(window, &windowSystem, &data1, &data2, errorMessage)) {
+			if (!DetermineVulkanWindowSystem(window, &windowDesc, errorMessage)) {
 				return false;
 			}
 			// NOTE : This should match the lines below in the Vulkan case.
@@ -2061,7 +2007,7 @@ int main(int argc, char *argv[]) {
 			});
 		}
 
-		if (!ctx->InitSurface(windowSystem, data1, data2, errorMessage)) {
+		if (!ctx->InitSurface(windowDesc.winsys, windowDesc.data1, windowDesc.data2, errorMessage)) {
 			fprintf(stderr, "Surface creation failed: %s\n", errorMessage->c_str());
 			return false;
 		}

SDL/SDLUtil.cpp

@@ -0,0 +1,66 @@
+#include <SDL3/SDL.h>
+
+#include "ppsspp_config.h"
+
+#if PPSSPP_PLATFORM(MAC) || PPSSPP_PLATFORM(IOS)
+#include "SDL/SDLCocoaMetalLayer.h"
+#endif
+
+#include "Common/GPU/MiscTypes.h"
+#include "Common/GPU/Vulkan/VulkanLoader.h"
+#include "Common/GPU/Vulkan/VulkanContext.h"
+#include "Common/GPU/GraphicsContext.h"
+
+#include "SDL/SDLUtil.h"
+
+bool DetermineVulkanWindowSystem(SDL_Window *window, WindowDesc *desc, std::string *errorMessage) {
+	_dbg_assert_(window);
+	SDL_PropertiesID windowProps = SDL_GetWindowProperties(window);
+	void *x11Display = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_X11_DISPLAY_POINTER, nullptr);
+	if (x11Display != nullptr) {
+		intptr_t x11Window = (intptr_t)SDL_GetNumberProperty(windowProps, SDL_PROP_WINDOW_X11_WINDOW_NUMBER, 0);
+#if defined(VK_USE_PLATFORM_XLIB_KHR)
+		desc->winsys = WINDOWSYSTEM_XLIB;
+		desc->data1 = x11Display;
+		desc->data2 = (void *)x11Window;
+#elif defined(VK_USE_PLATFORM_XCB_KHR)
+		desc->winsys = WINDOWSYSTEM_XCB;
+		desc->data1 = (void *)XGetXCBConnection((Display *)x11Display);
+		desc->data2 = (void *)x11Window;
+#endif
+		return true;
+	}
+#if defined(VK_USE_PLATFORM_WAYLAND_KHR)
+	void *waylandDisplay = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_WAYLAND_DISPLAY_POINTER, nullptr);
+	void *waylandSurface = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_WAYLAND_SURFACE_POINTER, nullptr);
+	if (waylandDisplay != nullptr && waylandSurface != nullptr) {
+		desc->winsys = WINDOWSYSTEM_WAYLAND;
+		desc->data1 = waylandDisplay;
+		desc->data2 = waylandSurface;
+		return true;
+	}
+#elif defined(VK_USE_PLATFORM_METAL_EXT)
+#if PPSSPP_PLATFORM(MAC)
+	void *cocoaWindow = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_COCOA_WINDOW_POINTER, nullptr);
+	if (cocoaWindow != nullptr) {
+		desc->winsys = WINDOWSYSTEM_METAL_EXT;
+		desc->data1 = makeWindowMetalCompatible(cocoaWindow);
+		desc->data2 = nullptr;
+		return true;
+	}
+#else
+	// This path is currently not used as we do not use SDL on iOS, but it is here for completeness.
+	void *uikitWindow = SDL_GetPointerProperty(windowProps, SDL_PROP_WINDOW_UIKIT_WINDOW_POINTER, nullptr);
+	if (uikitWindow != nullptr) {
+		desc->winsys = WINDOWSYSTEM_METAL_EXT;
+		desc->data1 = makeWindowMetalCompatible(uikitWindow);
+		desc->data2 = nullptr;
+		return true;
+	}
+#endif
+#endif  // VK_USE_PLATFORM_METAL_EXT
+	if (errorMessage) {
+		*errorMessage = "Unable to determine Vulkan window system from SDL3 window properties";
+	}
+	return false;
+}

SDL/SDLUtil.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include <SDL3/SDL.h>
+#include "Common/GPU/MiscTypes.h"
+#include <string>
+
+struct WindowDesc;
+
+bool DetermineVulkanWindowSystem(SDL_Window *window, WindowDesc *desc, std::string *errorMessage);

headless/Headless.cpp

@@ -228,7 +228,15 @@ void System_SendDebugScreenshot(const uint8_t *data, int width, int height) {
 static GraphicsContext *CreateGraphicsContext(GPUCore gpuCore, std::string **deviceSetting) {
 #ifdef SDL
 	*deviceSetting = nullptr;
-	return new SDLHeadlessGLGraphicsContext();
+	switch (gpuCore) {
+	case GPUCORE_GLES:
+		return new SDLHeadlessGLGraphicsContext();
+	case GPUCORE_VULKAN:
+		*deviceSetting = &g_Config.sVulkanDevice;
+		return new VulkanGraphicsContext();
+	default:
+		return nullptr;
+	}
 #elif PPSSPP_PLATFORM(WINDOWS) && !PPSSPP_PLATFORM(UWP)
 	switch (gpuCore) {
 #if PPSSPP_API(ANY_GL)
@@ -244,8 +252,7 @@ static GraphicsContext *CreateGraphicsContext(GPUCore gpuCore, std::string **dev
 		return new VulkanGraphicsContext();
 	case GPUCORE_SOFTWARE:
 	default:
-		_assert_(false);
-		break;
+		return nullptr;
 	}
 #elif PPSSPP_ARCH(LOONGARCH64)
 	// The loongarch64 cross-compilation toolchain has no SDL3 packages available (see the
@@ -260,8 +267,8 @@ static GraphicsContext *CreateGraphicsContext(GPUCore gpuCore, std::string **dev
 	return nullptr;
 #else
 #error The Headless build is not supported on this platform. Please use SDL (Mac/Linux) or Windows (non-UWP).
-#endif
 	return nullptr;
+#endif
 }
 
 struct AutoTestOptions {
@@ -675,6 +682,7 @@ int main(int argc, const char* argv[]) {
 	// Time to set up graphics
 	GraphicsContext *graphicsContext = nullptr;
 	std::string *deviceSetting = nullptr;
+	void *window = nullptr;
 	WindowDesc windowDesc;
 	if (g_Config.bSoftwareRendering) {
 		// For software rendering, we just create a dummy graphics context (to share as much code as possible).
@@ -686,7 +694,7 @@ int main(int argc, const char* argv[]) {
 		return 1;
 #else
 		// TODO: Will we need a larger window for higher resolutions? Well, not if we use buffered rendering.
-		windowDesc = CreateHiddenWindow(480, 272, cmdLineOptions.gpuBackend.value());
+		window = CreateHiddenWindow(480, 272, cmdLineOptions.gpuBackend.value(), &windowDesc);
 		if (!windowDesc.Valid()) {
 			fprintf(stderr, "Failed to create a window for graphics context");
 			return 1;
@@ -811,8 +819,8 @@ int main(int argc, const char* argv[]) {
 #if PPSSPP_PLATFORM(ANDROID) || PPSSPP_ARCH(LOONGARCH64)
 	// ... see above
 #else
-	if (windowDesc.Valid()) {
-		DestroyHiddenWindow(windowDesc);
+	if (window) {
+		DestroyHiddenWindow(window,	windowDesc);
 	}
 #endif
 

headless/Headless.vcxproj

@@ -338,6 +338,14 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
     </ClCompile>
+    <ClCompile Include="..\SDL\SDLUtil.cpp">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+    </ClCompile>
     <ClCompile Include="..\Windows\CaptureDevice.cpp" />
     <ClCompile Include="..\Windows\GPU\D3D11Context.cpp" />
     <ClCompile Include="..\Windows\GPU\WindowsGLContext.cpp">
@@ -399,8 +407,23 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\Common\GPU\Vulkan\VulkanGraphicsContext.h" />
+    <ClInclude Include="..\SDL\SDLUtil.h">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+    </ClInclude>
     <ClInclude Include="Compare.h" />
-    <ClInclude Include="SDLHeadlessGLGraphicsContext.h" />
+    <ClInclude Include="SDLHeadlessGLGraphicsContext.h">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+    </ClInclude>
     <ClInclude Include="WindowsHeadlessHost.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />

headless/Headless.vcxproj.filters

@@ -25,6 +25,9 @@
     <ClCompile Include="..\Common\GPU\Vulkan\VulkanGraphicsContext.cpp">
       <Filter>Windows</Filter>
     </ClCompile>
+    <ClCompile Include="..\SDL\SDLUtil.cpp">
+      <Filter>Other Platforms</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\test.py" />
@@ -41,6 +44,9 @@
     <ClInclude Include="..\Common\GPU\Vulkan\VulkanGraphicsContext.h">
       <Filter>Windows</Filter>
     </ClInclude>
+    <ClInclude Include="..\SDL\SDLUtil.h">
+      <Filter>Other Platforms</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Windows">

headless/SDLHeadlessGLGraphicsContext.cpp

@@ -34,10 +34,11 @@
 #include "Core/Config.h"
 #include "Core/System.h"
 #include "GPU/GPUState.h"
+#include "SDL/SDLUtil.h"
 
 const bool WINDOW_VISIBLE = false;
 
-WindowDesc CreateHiddenWindow(int w, int h, GPUBackend backend) {
+void *CreateHiddenWindow(int w, int h, GPUBackend backend, WindowDesc *desc) {
 	Uint32 flags = SDL_WINDOW_BORDERLESS;
 	if (backend == GPUBackend::OPENGL) {
 		flags |= SDL_WINDOW_OPENGL;
@@ -47,20 +48,33 @@ WindowDesc CreateHiddenWindow(int w, int h, GPUBackend backend) {
 	if (!WINDOW_VISIBLE) {
 		flags |= SDL_WINDOW_HIDDEN;
 	}
-	WindowDesc desc;
-	desc.data2 = SDL_CreateWindow("PPSSPPHeadless", w, h, flags);
-	desc.winsys = WindowSystem::WINDOWSYSTEM_SDL;
-	if (!desc.data2) {
+
+	SDL_Window *window = SDL_CreateWindow("PPSSPPHeadless", w, h, flags);
+	if (!window) {
 		const char *err = SDL_GetError();
-		printf("Failed to create offscreen window: %s\n", err ? err : "(unknown error)");
-		return {};
+		fprintf(stderr, "Failed to create offscreen window: %s\n", err ? err : "(unknown error)");
+		return nullptr;
 	}
-	return desc;
+
+	if (backend == GPUBackend::VULKAN) {
+		// Overwrite the surface init params with what we need for Vulkan..
+		std::string errorMessage;
+		if (!DetermineVulkanWindowSystem(window, desc, &errorMessage)) {
+			fprintf(stderr, "Failed to determine Vulkan window system: %s\n", errorMessage.c_str());
+			SDL_DestroyWindow(window);
+			return nullptr;
+		}
+	} else {
+		desc->winsys = WindowSystem::WINDOWSYSTEM_SDL;
+		// For OpenGL, we just need the SDL_Window pointer.
+		desc->data2 = window;
+	}
+	return window;
 }
 
-void DestroyHiddenWindow(WindowDesc window) {
-	if (window.data2) {
-		SDL_DestroyWindow(static_cast<SDL_Window *>(window.data2));
+void DestroyHiddenWindow(void *window, WindowDesc desc) {
+	if (window) {
+		SDL_DestroyWindow(static_cast<SDL_Window *>(window));
 		SDL_Quit();
 	}
 }

headless/SDLHeadlessGLGraphicsContext.h

@@ -67,7 +67,7 @@ private:
 	SDL_GLContext glContext_;
 };
 
-WindowDesc CreateHiddenWindow(int w, int h, GPUBackend backend);
-void DestroyHiddenWindow(WindowDesc window);
+void *CreateHiddenWindow(int w, int h, GPUBackend backend, WindowDesc *desc);
+void DestroyHiddenWindow(void *window, WindowDesc desc);
 
 #endif

headless/WindowsHeadlessHost.cpp

@@ -23,7 +23,7 @@
 
 const bool WINDOW_VISIBLE = false;
 
-WindowDesc CreateHiddenWindow(int w, int h, GPUBackend backend) {
+void *CreateHiddenWindow(int w, int h, GPUBackend backend, WindowDesc *desc) {
 	static WNDCLASSEX wndClass = {
 		sizeof(WNDCLASSEX),
 		CS_HREDRAW | CS_VREDRAW | CS_OWNDC,
@@ -47,15 +47,15 @@ WindowDesc CreateHiddenWindow(int w, int h, GPUBackend backend) {
 		ShowWindow(wnd, TRUE);
 		SetFocus(wnd);
 	}
-	WindowDesc desc;
-	desc.data1 = GetModuleHandle(NULL);
-	desc.data2 = wnd;
-	desc.winsys = WindowSystem::WINDOWSYSTEM_WIN32;
-	return desc;
+	desc->data1 = GetModuleHandle(NULL);  // easy way to get the HINSTANCE.
+	desc->data2 = wnd;
+	desc->winsys = WindowSystem::WINDOWSYSTEM_WIN32;
+	return static_cast<void *>(wnd);
 }
 
-void DestroyHiddenWindow(WindowDesc window) {
-	if (window.data2) {
-		DestroyWindow(static_cast<HWND>(window.data2));
+void DestroyHiddenWindow(void *window, WindowDesc desc) {
+	if (window) {
+		DestroyWindow(static_cast<HWND>(window));
+		UnregisterClass(L"PPSSPPHeadless", static_cast<HINSTANCE>(desc.data1));
 	}
 }

headless/WindowsHeadlessHost.h

@@ -22,5 +22,5 @@
 struct WindowDesc;
 
 // Same API as for SDL
-WindowDesc CreateHiddenWindow(int w, int h, GPUBackend backend);
-void DestroyHiddenWindow(WindowDesc window);
+void *CreateHiddenWindow(int w, int h, GPUBackend backend, WindowDesc *desc);
+void DestroyHiddenWindow(void *window, WindowDesc desc);