use direct write to get system fonts

openVulkanoCpp/Host/Windows/SystemFontResolver.cpp

@@ -6,11 +6,35 @@
 
 #include "Host/SystemFontResolver.hpp"
 #include "Base/Utils.hpp"
+#include "Base/Logger.hpp"
 #include <Windows.h>
+#include <dwrite_3.h>
 #include <filesystem>
 
 #define QFR_DESCRIPTION 1
 
+#pragma comment(lib, "Dwrite.lib")
+
+namespace
+{
+	template<typename T>
+	struct DirectWriteAutoReleasable final
+	{
+		DirectWriteAutoReleasable() : ptr(nullptr) {}
+		~DirectWriteAutoReleasable()
+		{
+			if (ptr)
+			{
+				ptr->Release();
+			}
+		}
+
+		T* operator->() { return ptr; }
+
+		T* ptr;
+	};
+}
+
 namespace OpenVulkano
 {
 	const std::string& SystemFontResolver::GetSystemFontPath(const std::string& fontName)
@@ -24,35 +48,92 @@ namespace OpenVulkano
 
 	std::map<std::string, std::string> SystemFontResolver::ReadSystemFonts()
 	{
+		DirectWriteAutoReleasable<IDWriteFactory7> dwrite;
+		HRESULT hr = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED, __uuidof(IDWriteFactory7), (IUnknown**) &dwrite);
+		if (!SUCCEEDED(hr))
+		{
+			Logger::DATA->error("Could not read system fonts. DWriteCreateFactory has failed. Error code {}", hr);
+			return {};
+		}
+		
+		DirectWriteAutoReleasable<IDWriteFontSet> matchingFonts;
+		hr = dwrite->GetSystemFontSet(&matchingFonts.ptr);
+		if (!SUCCEEDED(hr))
+		{
+			Logger::DATA->error("Could not read system fonts. GetSystemFontSet has failed. Error code {}", hr);
+			return {};
+		}
+		
 		std::map<std::string, std::string> fontFileMapping;
+		const UINT32 familyCount = matchingFonts->GetFontCount();
 		// thank you Microsoft for function that is not even documented, but exists and it's the only function that
 		// can return real font name from font filename (e.g. font filename is times.ttf that corresponds to Times New Roman)
 		int(WINAPI* GetFontResourceInfoW)(wchar_t*, unsigned long*, void*, unsigned long);
 		*(FARPROC*) &GetFontResourceInfoW = GetProcAddress(GetModuleHandleA("gdi32"), "GetFontResourceInfoW");
 
-		std::wstring winDir;
-		winDir.resize(MAX_PATH);
-		UINT len = GetWindowsDirectoryW(winDir.data(), MAX_PATH);
-		winDir.resize(len);
-		std::filesystem::path fontsDir = std::filesystem::path(winDir) / "Fonts";
-		for (const auto& fontFilename : std::filesystem::directory_iterator(fontsDir))
+		for (UINT32 i = 0; i < familyCount; ++i)
 		{
-			unsigned long size = 0;
-			std::wstring ws = fontFilename.path().wstring();
-			if (!GetFontResourceInfoW(ws.data(), &size, NULL, QFR_DESCRIPTION))
+			DirectWriteAutoReleasable<IDWriteFontFaceReference> faceRef;
+			hr = matchingFonts->GetFontFaceReference(i, &faceRef.ptr);
+			if (!SUCCEEDED(hr))
 			{
 				continue;
 			}
+
+			DirectWriteAutoReleasable<IDWriteFontFile> file;
+			hr = faceRef->GetFontFile(&file.ptr);
+			if (!SUCCEEDED(hr))
+			{
+				continue;
+			}
+
+			DirectWriteAutoReleasable<IDWriteFontFileLoader> loader;
+			hr = file->GetLoader(&loader.ptr);
+			if (!SUCCEEDED(hr))
+			{
+				continue;
+			}
+
+			DirectWriteAutoReleasable<IDWriteLocalFontFileLoader> localLoader;
+			hr = loader->QueryInterface(&localLoader.ptr);
+			if (!SUCCEEDED(hr))
+			{
+				continue;
+			}
+
+			const void* fileKey;
+			UINT32 fileKeySize;
+			hr = file->GetReferenceKey(&fileKey, &fileKeySize);
+			if (!SUCCEEDED(hr))
+			{
+				continue;
+			}
+
+			// Get font path
+			WCHAR filePath[MAX_PATH];
+			hr = localLoader->GetFilePathFromKey(fileKey, fileKeySize, filePath, MAX_PATH);
+			if (!SUCCEEDED(hr))
+			{
+				continue;
+			}
+
+			// Get font name
+			unsigned long size = 0;
+			if (!GetFontResourceInfoW(filePath, &size, NULL, QFR_DESCRIPTION))
+			{
+				continue;
+			}
+
 			std::wstring fontName;
 			fontName.resize(size);
-			if (GetFontResourceInfoW(ws.data(), &size, fontName.data(), QFR_DESCRIPTION))
+			if (GetFontResourceInfoW(filePath, &size, fontName.data(), QFR_DESCRIPTION))
 			{
 				// remove null-terminated characters since size is always bigger than needed
 				std::string fontNameCropped(fontName.begin(), fontName.end());
-				size_t realSize = strlen(fontNameCropped.data());
+				const size_t realSize = strlen(fontNameCropped.data());
 				fontNameCropped.resize(realSize);
 				Utils::ToLower(fontNameCropped);
-				fontFileMapping[std::move(fontNameCropped)] = fontFilename.path().string();
+				fontFileMapping[std::move(fontNameCropped)] = std::string(filePath, filePath + wcslen(filePath));
 			}
 		}
 		return fontFileMapping;