From fe8abe9d5afc4843b7492ec25e0f091e796455c5 Mon Sep 17 00:00:00 2001
From: narzoul <narzoul@users.noreply.github.com>
Date: Mon, 2 May 2016 23:53:36 +0200
Subject: [PATCH] Avoid side effects when method implementations are delegated
 to higher versions

Some DirectDraw methods are implemented by delegating to the same method
in a higher interface version. In this case, the hooking logic could be
executed twice, leading to unwanted side effects. This is now avoided.
---
 DDrawCompat/CompatDirectDraw.cpp        | 112 +++++++++++++-----------
 DDrawCompat/CompatDirectDrawSurface.cpp |   4 +-
 2 files changed, 62 insertions(+), 54 deletions(-)

diff --git a/DDrawCompat/CompatDirectDraw.cpp b/DDrawCompat/CompatDirectDraw.cpp
index 55d6415..21d1f45 100644
--- a/DDrawCompat/CompatDirectDraw.cpp
+++ b/DDrawCompat/CompatDirectDraw.cpp
@@ -17,14 +17,69 @@ namespace
 		return DDENUMRET_CANCEL;
 	}
 
-	DWORD getRefreshRate()
+	template <typename TDirectDraw>
+	HRESULT setDisplayMode(TDirectDraw* This, DWORD dwWidth, DWORD dwHeight, DWORD dwBPP,
+		DWORD dwRefreshRate, DWORD dwFlags)
 	{
-		return 0;
+		typename Types<TDirectDraw>::TSurfaceDesc desc = {};
+		desc.dwSize = sizeof(desc);
+		desc.dwFlags = DDSD_WIDTH | DDSD_HEIGHT | DDSD_PIXELFORMAT;
+		desc.dwWidth = dwWidth;
+		desc.dwHeight = dwHeight;
+		desc.ddpfPixelFormat.dwSize = sizeof(desc.ddpfPixelFormat);
+		desc.ddpfPixelFormat.dwFlags = DDPF_RGB;
+		desc.ddpfPixelFormat.dwRGBBitCount = dwBPP;
+
+		switch (dwBPP)
+		{
+		case 1: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED1; break;
+		case 2: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED2; break;
+		case 4: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED4; break;
+		case 8: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED8; break;
+		}
+
+		DDPIXELFORMAT pf = {};
+		if (dwBPP > 8)
+		{
+			if (FAILED(CompatDirectDraw<TDirectDraw>::s_origVtable.EnumDisplayModes(
+				This, 0, &desc, &pf, &enumDisplayModesCallback)) || 0 == pf.dwSize)
+			{
+				Compat::Log() << "Failed to find the requested display mode: " <<
+					dwWidth << "x" << dwHeight << "x" << dwBPP;
+				return DDERR_INVALIDMODE;
+			}
+		}
+		else
+		{
+			pf = desc.ddpfPixelFormat;
+		}
+
+		HRESULT result = CompatDirectDraw<TDirectDraw>::s_origVtable.SetDisplayMode(
+			This, dwWidth, dwHeight, 32, dwRefreshRate, dwFlags);
+		if (SUCCEEDED(result))
+		{
+			CompatPrimarySurface::displayMode.width = dwWidth;
+			CompatPrimarySurface::displayMode.height = dwHeight;
+			CompatPrimarySurface::displayMode.pixelFormat = pf;
+			CompatPrimarySurface::displayMode.refreshRate = dwRefreshRate;
+			CompatPrimarySurface::isDisplayModeChanged = true;
+		}
+		else
+		{
+			Compat::Log() << "Failed to set the display mode to " << dwWidth << "x" << dwHeight << "x32";
+		}
+
+		return result;
 	}
 
-	DWORD getRefreshRate(DWORD dwRefreshRate, DWORD /*dwFlags*/)
+	HRESULT setDisplayMode(IDirectDraw* This, DWORD dwWidth, DWORD dwHeight, DWORD dwBPP)
 	{
-		return dwRefreshRate;
+		IDirectDraw7* dd = nullptr;
+		CompatDirectDraw<IDirectDraw>::s_origVtable.QueryInterface(
+			This, IID_IDirectDraw7, reinterpret_cast<void**>(&dd));
+		HRESULT result = setDisplayMode(dd, dwWidth, dwHeight, dwBPP, 0, 0);
+		CompatDirectDraw<IDirectDraw7>::s_origVtable.Release(dd);
+		return result;
 	}
 }
 
@@ -116,54 +171,7 @@ HRESULT STDMETHODCALLTYPE CompatDirectDraw<TDirectDraw>::SetDisplayMode(
 	DWORD dwBPP,
 	Params... params)
 {
-	TSurfaceDesc desc = {};
-	desc.dwSize = sizeof(desc);
-	desc.dwFlags = DDSD_WIDTH | DDSD_HEIGHT | DDSD_PIXELFORMAT;
-	desc.dwWidth = dwWidth;
-	desc.dwHeight = dwHeight;
-	desc.ddpfPixelFormat.dwSize = sizeof(desc.ddpfPixelFormat);
-	desc.ddpfPixelFormat.dwFlags = DDPF_RGB;
-	desc.ddpfPixelFormat.dwRGBBitCount = dwBPP;
-
-	switch (dwBPP)
-	{
-	case 1: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED1; break;
-	case 2: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED2; break;
-	case 4: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED4; break;
-	case 8: desc.ddpfPixelFormat.dwFlags |= DDPF_PALETTEINDEXED8; break;
-	}
-
-	DDPIXELFORMAT pf = {};
-	if (dwBPP > 8)
-	{
-		if (FAILED(s_origVtable.EnumDisplayModes(This, 0, &desc, &pf, &enumDisplayModesCallback)) ||
-			0 == pf.dwSize)
-		{
-			Compat::Log() << "Failed to find the requested display mode: " <<
-				dwWidth << "x" << dwHeight << "x" << dwBPP;
-			return DDERR_INVALIDMODE;
-		}
-	}
-	else
-	{
-		pf = desc.ddpfPixelFormat;
-	}
-
-	HRESULT result = s_origVtable.SetDisplayMode(This, dwWidth, dwHeight, 32, params...);
-	if (SUCCEEDED(result))
-	{
-		CompatPrimarySurface::displayMode.width = dwWidth;
-		CompatPrimarySurface::displayMode.height = dwHeight;
-		CompatPrimarySurface::displayMode.pixelFormat = pf;
-		CompatPrimarySurface::displayMode.refreshRate = getRefreshRate(params...);
-		CompatPrimarySurface::isDisplayModeChanged = true;
-	}
-	else
-	{
-		Compat::Log() << "Failed to set the display mode to " << dwWidth << "x" << dwHeight << "x32";
-	}
-
-	return result;
+	return setDisplayMode(This, dwWidth, dwHeight, dwBPP, params...);
 }
 
 template CompatDirectDraw<IDirectDraw>;
diff --git a/DDrawCompat/CompatDirectDrawSurface.cpp b/DDrawCompat/CompatDirectDrawSurface.cpp
index 5e3ece2..3538eae 100644
--- a/DDrawCompat/CompatDirectDrawSurface.cpp
+++ b/DDrawCompat/CompatDirectDrawSurface.cpp
@@ -565,8 +565,8 @@ HRESULT STDMETHODCALLTYPE CompatDirectDrawSurface<TSurface>::Unlock(TSurface* Th
 template <typename TSurface>
 void CompatDirectDrawSurface<TSurface>::restorePrimaryCaps(TDdsCaps& caps)
 {
-	caps.dwCaps ^= DDSCAPS_OFFSCREENPLAIN;
-	caps.dwCaps |= DDSCAPS_PRIMARYSURFACE | DDSCAPS_VISIBLE;
+	caps.dwCaps &= ~(DDSCAPS_OFFSCREENPLAIN | DDSCAPS_SYSTEMMEMORY);
+	caps.dwCaps |= DDSCAPS_PRIMARYSURFACE | DDSCAPS_VISIBLE | DDSCAPS_VIDEOMEMORY | DDSCAPS_LOCALVIDMEM;
 }
 
 template <> const IID& CompatDirectDrawSurface<IDirectDrawSurface>::s_iid = IID_IDirectDrawSurface;