- some improvements to compatibility scripts:

* use names, not strings, to allow use of switch/case.
* avoid creating the checksum a second time per level.
* do an early-out check for maps that do not have scripted compatibility.

src/compatibility.cpp

@@ -466,7 +466,7 @@ void ParseCompatibility()
 //
 //==========================================================================
 
-void CheckCompatibility(MapData *map)
+FName CheckCompatibility(MapData *map)
 {
 	FMD5Holder md5;
 	FCompatValues *flags;
@@ -489,13 +489,16 @@ void CheckCompatibility(MapData *map)
 
 	flags = BCompatMap.CheckKey(md5);
 
-	if (developer >= DMSG_NOTIFY)
-	{
-		Printf("MD5 = ");
+	FString hash;
+
 	for (size_t j = 0; j < sizeof(md5.Bytes); ++j)
 	{
-			Printf("%02X", md5.Bytes[j]);
+		hash.AppendFormat("%02X", md5.Bytes[j]);
 	}
+
+	if (developer >= DMSG_NOTIFY)
+	{
+		Printf("MD5 = %s", hash.GetChars());
 		if (flags != NULL)
 		{
 			Printf(", cflags = %08x, cflags2 = %08x, bflags = %08x\n",
@@ -523,6 +526,7 @@ void CheckCompatibility(MapData *map)
 	{
 		ib_compatflags |= BCOMPATF_FLOATBOB;
 	}
+	return FName(hash, true);	// if this returns NAME_None it means there is no scripted compatibility handler.
 }
 
 //==========================================================================
@@ -531,7 +535,9 @@ void CheckCompatibility(MapData *map)
 //
 //==========================================================================
 
-void SetCompatibilityParams()
+void SetCompatibilityParams(FName checksum)
+{
+	if (checksum != NAME_None)
 	{
 		PClass *const cls = PClass::FindClass("LevelCompatibility");
 		if (cls != nullptr)
@@ -539,7 +545,9 @@ void SetCompatibilityParams()
 			PFunction *const func = dyn_cast<PFunction>(cls->FindSymbol("Apply", true));
 			if (func != nullptr)
 			{
-			VMCall(func->Variants[0].Implementation, nullptr, 0, nullptr, 0);
+				VMValue param = { (int)checksum };
+				VMCall(func->Variants[0].Implementation, &param, 1, nullptr, 0);
+			}
 		}
 	}
 

src/compatibility.h

@@ -36,7 +36,7 @@ struct FMD5HashTraits
 extern TMap<FMD5Holder, FCompatValues, FMD5HashTraits> BCompatMap;
 
 void ParseCompatibility();
-void CheckCompatibility(MapData *map);
-void SetCompatibilityParams();
+FName CheckCompatibility(MapData *map);
+void SetCompatibilityParams(FName);
 
 #endif

src/p_setup.cpp

@@ -3756,7 +3756,7 @@ void P_SetupLevel (const char *lumpname, int position)
 		{
 			level.maptype = MAPTYPE_UDMF;
 		}
-		CheckCompatibility(map);
+		FName checksum = CheckCompatibility(map);
 		if (ib_compatflags & BCOMPATF_REBUILDNODES)
 		{
 			ForceNodeBuild = true;
@@ -3834,7 +3834,7 @@ void P_SetupLevel (const char *lumpname, int position)
 			times[0].Unclock();
 		}
 
-		SetCompatibilityParams();
+		SetCompatibilityParams(checksum);
 
 		times[6].Clock();
 		P_LoopSidedefs (true);

wadsrc/static/zscript/level_compatibility.txt

@@ -1,12 +1,12 @@
 
 class LevelCompatibility play
 {
-	private static void Apply()
+	private static void Apply(Name checksum)
 	{
-		string checksum = level.GetChecksum();
-
-		if (   checksum ~== "AB24AE6E2CB13CBDD04600A4D37F9189"   // doom2.wad map02
-			|| checksum ~== "1EC0AF1E3985650F0C9000319C599D0C")  // doom2bfg.wad map02
+		switch (checksum)
+		{
+			case 'AB24AE6E2CB13CBDD04600A4D37F9189':   // doom2.wad map02
+			case '1EC0AF1E3985650F0C9000319C599D0C':  // doom2bfg.wad map02
 			{
 				// Missing textures
 				TextureID stone4 = TexMan.CheckForTexture("STONE4", TexMan.Type_Wall);
@@ -14,11 +14,15 @@ class LevelCompatibility play
 				SetWallTextureID(328, Line.front, Side.bottom, stone4);
 				SetWallTextureID(338, Line.front, Side.bottom, stone4);
 				SetWallTextureID(339, Line.front, Side.bottom, stone4);
+				break;
 			}
-		else if (checksum ~== "66C46385EB1A23D60839D1532522076B")  // doom2.wad map08
+			
+			case '66C46385EB1A23D60839D1532522076B':  // doom2.wad map08
 			{
 				// Missing texture
 				SetWallTexture(101, Line.back, Side.top, "BRICK7");
+				break;
+			}
 		}
 	}