- started with a ScriptUtil class which will allow moving function implementations for ACS and FraggleScript to zscript.txt

So far 3 functions for testing implemented.

src/scriptutil.cpp

@@ -0,0 +1,104 @@
+//-----------------------------------------------------------------------------
+//
+// Copyright 2018 Christoph Oelckers
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see http://www.gnu.org/licenses/
+//
+//-----------------------------------------------------------------------------
+//
+//
+// DESCRIPTION: generalized interface for implementing ACS/FS functions
+// in ZScript.
+//
+//-----------------------------------------------------------------------------
+
+#include "i_system.h"
+#include "tarray.h"
+#include "dobject.h"
+#include "vm.h"
+#include "scriptutil.h"
+#include "p_acs.h"
+
+
+static TArray<VMValue> parameters;
+static TMap<FName, VMFunction*> functions;
+
+
+void ScriptUtil::BuildParameters(va_list ap)
+{
+	for(int type = va_arg(ap, int); type != End; type = va_arg(ap, int))
+	{
+		switch (type)
+		{
+			case Int:
+				parameters.Push(VMValue(va_arg(ap, int)));
+				break;
+				
+			case Pointer:
+			case Class:		// this is just a pointer.
+			case String:	// must be passed by reference to a persistent location!
+				parameters.Push(VMValue(va_arg(ap, void*)));
+				break;
+				
+			case Float:
+				parameters.Push(VMValue(va_arg(ap, double)));
+				break;
+				
+			case ACSClass:
+				parameters.Push(VMValue(PClass::FindActor(FBehavior::StaticLookupString(va_arg(ap, int)))));
+				break;
+		}
+	}
+}
+
+void ScriptUtil::RunFunction(FName functionname, unsigned paramstart, VMReturn &returns)
+{
+	VMFunction *func = nullptr;
+	auto check = functions.CheckKey(functionname);
+	if (!check)
+	{
+		PClass::FindFunction(&func, NAME_ScriptUtil, functionname);
+		if (func == nullptr) 
+		{
+			I_Error("Call to undefined function ScriptUtil.%s", functionname.GetChars());
+		}
+		functions.Insert(functionname, func);
+	}
+	else func = *check;
+
+	VMCall(func, &parameters[paramstart], parameters.Size() - paramstart, &returns, 1);
+}
+
+int ScriptUtil::Exec(FName functionname, ...)
+{
+	unsigned paramstart = parameters.Size();
+	va_list ap;
+	va_start(ap, functionname);
+	try
+	{
+		BuildParameters(ap);
+		int ret = 0;
+		VMReturn returns(&ret);
+		RunFunction(functionname, paramstart, returns);
+		va_end(ap);
+		parameters.Clamp(paramstart);
+		return ret;
+	}
+	catch(...)
+	{
+		va_end(ap);
+		parameters.Clamp(paramstart);
+		throw;
+	}
+}