From a6d982ed04da7ff13ae3fa4a02989baf0836ee3d Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Mon, 6 Apr 2020 21:57:47 +0200
Subject: [PATCH] - resolve the single Doom specific dependency in the VM by
 using a callback.

---
 source/common/scripting/jit/jit_move.cpp | 2 +-
 source/common/scripting/vm/vm.h          | 2 ++
 source/common/scripting/vm/vmexec.cpp    | 3 +++
 source/common/scripting/vm/vmexec.h      | 3 +--
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/source/common/scripting/jit/jit_move.cpp b/source/common/scripting/jit/jit_move.cpp
index d6b870646..584de35a1 100644
--- a/source/common/scripting/jit/jit_move.cpp
+++ b/source/common/scripting/jit/jit_move.cpp
@@ -52,7 +52,7 @@ static int CastS2Co(FString *b) { return V_GetColor(nullptr, *b); }
 static void CastCo2S(FString *a, int b) { PalEntry c(b); a->Format("%02x %02x %02x", c.r, c.g, c.b); }
 static int CastS2So(FString *b) { return FSoundID(*b); }
 static void CastSo2S(FString* a, int b) { *a = soundEngine->GetSoundName(b); }
-static void CastSID2S(FString* a, unsigned int b) { *a = "";/* (b >= sprites.Size()) ? "TNT1" : sprites[b].name;*/ }
+static void CastSID2S(FString* a, unsigned int b) { VM_CastSpriteIDToString(a, b); }
 static void CastTID2S(FString *a, int b) { auto tex = TexMan.GetTexture(*(FTextureID*)&b); *a = (tex == nullptr) ? "(null)" : tex->GetName().GetChars(); }
 
 void JitCompiler::EmitCAST()
diff --git a/source/common/scripting/vm/vm.h b/source/common/scripting/vm/vm.h
index cb5c2dab5..0eeec06b4 100644
--- a/source/common/scripting/vm/vm.h
+++ b/source/common/scripting/vm/vm.h
@@ -56,6 +56,8 @@ extern FMemArena ClassDataAllocator;
 
 void JitRelease();
 
+extern void (*VM_CastSpriteIDToString)(FString* a, unsigned int b);
+
 
 typedef unsigned char		VM_UBYTE;
 typedef signed char			VM_SBYTE;
diff --git a/source/common/scripting/vm/vmexec.cpp b/source/common/scripting/vm/vmexec.cpp
index 088988bd7..6921d3dac 100644
--- a/source/common/scripting/vm/vmexec.cpp
+++ b/source/common/scripting/vm/vmexec.cpp
@@ -46,6 +46,9 @@
 extern cycle_t VMCycles[10];
 extern int VMCalls[10];
 
+// THe sprite ID to string cast is game specific so let's do it with a callback to remove the dependency and allow easier reuse.
+void (*VM_CastSpriteIDToString)(FString* a, unsigned int b) = [](FString* a, unsigned int b) { a->Format("%d", b); };
+
 // intentionally implemented in a different source file to prevent inlining.
 #if 0
 void ThrowVMException(VMException *x);
diff --git a/source/common/scripting/vm/vmexec.h b/source/common/scripting/vm/vmexec.h
index 0e28bee2a..72e0d0199 100644
--- a/source/common/scripting/vm/vmexec.h
+++ b/source/common/scripting/vm/vmexec.h
@@ -1711,7 +1711,6 @@ static int ExecScriptFunc(VMFrameStack *stack, VMReturn *ret, int numret)
 	return 0;
 }
 
-
 static double DoFLOP(int flop, double v)
 {
 	switch(flop)
@@ -1843,7 +1842,7 @@ static void DoCast(const VMRegisters &reg, const VMFrame *f, int a, int b, int c
 
 	case CAST_SID2S:
 		ASSERTS(a); ASSERTD(b);
-		reg.s[a] = "";// unsigned(reg.d[b]) >= sprites.Size() ? "TNT1" : sprites[reg.d[b]].name;
+		VM_CastSpriteIDToString(&reg.s[a], reg.d[b]);
 		break;
 
 	case CAST_TID2S: