From 4a83a15d785fef3cbd9668989773526ea1109573 Mon Sep 17 00:00:00 2001
From: narzoul <narzoul@users.noreply.github.com>
Date: Sun, 14 Feb 2016 17:11:34 +0100
Subject: [PATCH] Invalidate GDI content when palette changes

---
 DDrawCompat/CompatGdi.cpp        | 25 +++++++++++++++++++++++++
 DDrawCompat/CompatGdiDcCache.cpp | 12 +++++++++++-
 DDrawCompat/CompatGdiDcCache.h   |  1 +
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/DDrawCompat/CompatGdi.cpp b/DDrawCompat/CompatGdi.cpp
index 8d2c040..52b2f04 100644
--- a/DDrawCompat/CompatGdi.cpp
+++ b/DDrawCompat/CompatGdi.cpp
@@ -17,6 +17,9 @@ namespace
 	HANDLE g_ddUnlockEndEvent = nullptr;
 	bool g_isDelayedUnlockPending = false;
 
+	bool g_isPaletteUsed = false;
+	PALETTEENTRY g_usedPaletteEntries[256] = {};
+
 	FARPROC getProcAddress(HMODULE module, const char* procName)
 	{
 		if (!module || !procName)
@@ -142,6 +145,14 @@ namespace CompatGdi
 			++g_ddLockThreadRenderingRefCount;
 		}
 
+		if (!g_isPaletteUsed && CompatPrimarySurface::palette)
+		{
+			g_isPaletteUsed = true;
+			ZeroMemory(g_usedPaletteEntries, sizeof(g_usedPaletteEntries));
+			CompatPrimarySurface::palette->lpVtbl->GetEntries(
+				CompatPrimarySurface::palette, 0, 0, 256, g_usedPaletteEntries);
+		}
+
 		++g_renderingRefCount;
 		return true;
 	}
@@ -235,5 +246,19 @@ namespace CompatGdi
 	{
 		GdiScopedThreadLock gdiLock;
 		CompatGdiDcCache::clear();
+
+		if (g_isPaletteUsed && CompatPrimarySurface::palette)
+		{
+			g_isPaletteUsed = false;
+
+			PALETTEENTRY usedPaletteEntries[256] = {};
+			CompatPrimarySurface::palette->lpVtbl->GetEntries(
+				CompatPrimarySurface::palette, 0, 0, 256, usedPaletteEntries);
+
+			if (0 != memcmp(usedPaletteEntries, g_usedPaletteEntries, sizeof(usedPaletteEntries)))
+			{
+				invalidate();
+			}
+		}
 	}
 }
diff --git a/DDrawCompat/CompatGdiDcCache.cpp b/DDrawCompat/CompatGdiDcCache.cpp
index 5a8479b..7f64934 100644
--- a/DDrawCompat/CompatGdiDcCache.cpp
+++ b/DDrawCompat/CompatGdiDcCache.cpp
@@ -14,6 +14,7 @@ namespace
 	
 	std::vector<CachedDc> g_cache;
 	DWORD g_cacheSize = 0;
+	DWORD g_cacheId = 0;
 	DWORD g_maxUsedCacheSize = 0;
 	DWORD g_ddLockThreadId = 0;
 
@@ -67,6 +68,7 @@ namespace
 
 		cachedDc.surface = surface;
 		cachedDc.dc = dc;
+		cachedDc.cacheId = g_cacheId;
 		return cachedDc;
 	}
 
@@ -150,6 +152,7 @@ namespace CompatGdiDcCache
 		}
 		g_cache.clear();
 		g_cacheSize = 0;
+		++g_cacheId;
 	}
 
 	CachedDc getDc()
@@ -189,7 +192,14 @@ namespace CompatGdiDcCache
 
 	void releaseDc(const CachedDc& cachedDc)
 	{
-		g_cache.push_back(cachedDc);
+		if (cachedDc.cacheId == g_cacheId)
+		{
+			g_cache.push_back(cachedDc);
+		}
+		else
+		{
+			releaseCachedDc(cachedDc);
+		}
 	}
 
 	void setDdLockThreadId(DWORD ddLockThreadId)
diff --git a/DDrawCompat/CompatGdiDcCache.h b/DDrawCompat/CompatGdiDcCache.h
index 28aec75..b0517a3 100644
--- a/DDrawCompat/CompatGdiDcCache.h
+++ b/DDrawCompat/CompatGdiDcCache.h
@@ -12,6 +12,7 @@ namespace CompatGdiDcCache
 	{
 		IDirectDrawSurface7* surface;
 		HDC dc;
+		DWORD cacheId;
 	};
 
 	void clear();