AcrylicWindow.cpp

#include <dcomp.h>
#include <dwmapi.h>
#include <wrl\implements.h>

#pragma comment(lib, "dcomp")
#pragma comment(lib, "dwmapi")

using namespace Microsoft::WRL;
struct CompositionAttrData { int Attrib; void* pvData; DWORD cbData; };

class AcrylicCompositor
{
public:
	HWND hwnd;
	HTHUMBNAIL topLevelWindowThumbnail;

	ComPtr<IDCompositionDesktopDevice> device;
	ComPtr<IDCompositionTranslateTransform> translateTransform;
	ComPtr<IDCompositionVisual2> rootVisual;
	ComPtr<IDCompositionTarget> target;

	int x = GetSystemMetrics(SM_CXSCREEN);
	int y = GetSystemMetrics(SM_CYSCREEN);
	RECT sourceRect{ 0, 0, x, y };
	SIZE destinationSize{ x, y };

	typedef HRESULT(WINAPI* DwmpCreateSharedThumbnailVisual)(IN HWND hwndDestination, IN HWND hwndSource, IN DWORD dwThumbnailFlags, IN DWM_THUMBNAIL_PROPERTIES* pThumbnailProperties, IN VOID* pDCompDevice, OUT VOID** ppVisual, OUT PHTHUMBNAIL phThumbnailId);
	typedef HRESULT(WINAPI* DwmpCreateSharedMultiWindowVisual)(IN HWND hwndDestination, IN VOID* pDCompDevice, OUT VOID** ppVisual, OUT PHTHUMBNAIL phThumbnailId);
	typedef HRESULT(WINAPI* DwmpUpdateSharedMultiWindowVisual)(IN HTHUMBNAIL hThumbnailId, IN HWND* phwndsInclude, IN DWORD chwndsInclude, IN HWND* phwndsExclude, IN DWORD chwndsExclude, OUT RECT* prcSource, OUT SIZE* pDestinationSize, IN DWORD dwFlags);
	typedef BOOL(WINAPI* SetCompAttr)(HWND, CompositionAttrData*);
	
	HMODULE dwmapi = LoadLibrary(L"dwmapi.dll");
	DwmpCreateSharedThumbnailVisual DwmCreateSharedThumbnailVisual = (DwmpCreateSharedThumbnailVisual)GetProcAddress(dwmapi, MAKEINTRESOURCEA(147));
	DwmpCreateSharedMultiWindowVisual DwmCreateSharedMultiWindowVisual = (DwmpCreateSharedMultiWindowVisual)GetProcAddress(dwmapi, MAKEINTRESOURCEA(163));
	DwmpUpdateSharedMultiWindowVisual DwmUpdateSharedMultiWindowVisual = (DwmpUpdateSharedMultiWindowVisual)GetProcAddress(dwmapi, MAKEINTRESOURCEA(164));
	SetCompAttr DwmSetWindowCompositionAttribute = (SetCompAttr)GetProcAddress(LoadLibrary(L"user32.dll"), "SetWindowCompositionAttribute");

	void ApplyAcrylic(HWND hwnd, int radius = 70, float saturation = 1.5)
	{
		this->hwnd = hwnd;

		int enable = 1;
		CompositionAttrData CompositionAttribute{ 13, &enable, sizeof(int) };
		DwmSetWindowCompositionAttribute(hwnd, &CompositionAttribute);

		Initialize();
		CreateBackdrop();
		CreateEffects(radius, saturation);
		SyncCoordinates(hwnd);
	}

	void Initialize() {
		DCompositionCreateDevice3(NULL, __uuidof (device), &device);
		device->CreateTargetForHwnd(hwnd, FALSE, &target);
		device->CreateVisual(&rootVisual);
		target->SetRoot(rootVisual.Get());
		device->CreateTranslateTransform(&translateTransform);
		rootVisual->SetTransform(translateTransform.Get());
	}

	void CreateEffects(int radius, float saturation) {
		ComPtr<IDCompositionDevice3> device3;
		device->QueryInterface(__uuidof (IDCompositionDevice3), &device3);

		ComPtr<IDCompositionSaturationEffect> saturationEffect;
		device3->CreateSaturationEffect(&saturationEffect);
		saturationEffect->SetSaturation(saturation);

		ComPtr<IDCompositionGaussianBlurEffect> blurEffect;
		device3->CreateGaussianBlurEffect(&blurEffect);
		blurEffect->SetBorderMode(D2D1_BORDER_MODE_HARD);
		blurEffect->SetStandardDeviation(radius);
	
		blurEffect->SetInput(0, saturationEffect.Get(), 0);
		rootVisual->SetEffect(blurEffect.Get());
	}

	void CreateBackdrop()
	{
		HTHUMBNAIL desktopThumbnail = NULL;
		DWM_THUMBNAIL_PROPERTIES thumbnailProperties{};
		thumbnailProperties.dwFlags = DWM_TNP_VISIBLE | DWM_TNP_RECTDESTINATION;
		thumbnailProperties.fVisible = TRUE;
		thumbnailProperties.rcDestination = sourceRect;

		ComPtr<IDCompositionVisual2> desktopWindowVisual;
		HWND desktopWindow = FindWindow(L"Progman", nullptr);
		DwmCreateSharedThumbnailVisual(hwnd, desktopWindow, 2, &thumbnailProperties, device.Get(), &desktopWindowVisual, &desktopThumbnail);
		
		ComPtr<IDCompositionVisual2> topLevelWindowVisual;
		DwmCreateSharedMultiWindowVisual(hwnd, device.Get(), &topLevelWindowVisual, &topLevelWindowThumbnail);

		rootVisual->AddVisual(desktopWindowVisual.Get(), false, NULL);
		rootVisual->AddVisual(topLevelWindowVisual.Get(), true, desktopWindowVisual.Get());
	}

	void SyncCoordinates(HWND hwnd)
	{
		RECT hostWindowRect{};
		GetWindowRect(hwnd, &hostWindowRect);
		translateTransform->SetOffsetX(-hostWindowRect.left - (GetSystemMetrics(SM_CYFRAME) + GetSystemMetrics(SM_CXPADDEDBORDER)));
		translateTransform->SetOffsetY(-hostWindowRect.top - GetSystemMetrics(SM_CYCAPTION));
		
		DwmUpdateSharedMultiWindowVisual(topLevelWindowThumbnail, nullptr, 0, NULL, 0, &sourceRect, &destinationSize, 1);
		device->Commit();	
	}
};


AcrylicCompositor compositor;

#ifdef BUILD_DLL
extern "C" __declspec(dllexport) void ApplyAcrylic(HWND hwnd, int radius, float saturation) { compositor.ApplyAcrylic(hwnd, radius, saturation); }
extern "C" __declspec(dllexport) void SyncWindowPosition(HWND hwnd) { compositor.SyncCoordinates(hwnd); }
#else

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
bool acrylicEnabled;

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow)
{
	WNDCLASS wc = { };
	wc.lpfnWndProc = WindowProc;
	wc.hInstance = hInstance;
	wc.lpszClassName = L"Acrylic Window";
	RegisterClass(&wc);

	HWND hwnd = CreateWindowEx(WS_EX_NOREDIRECTIONBITMAP, wc.lpszClassName, wc.lpszClassName, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
	ShowWindow(hwnd, nCmdShow);

	compositor.ApplyAcrylic(hwnd);
	acrylicEnabled = true;

	MSG msg = { };
	while (GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch (uMsg)
	{
	case WM_WINDOWPOSCHANGED:
		if (acrylicEnabled) compositor.SyncCoordinates(hwnd);
		break;

	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	}

	return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

#endif