From b121284fc023b6a211cfaa23d822d088cab40aaa Mon Sep 17 00:00:00 2001
From: MajorCooke <paul.growney22@gmail.com>
Date: Fri, 24 Jun 2016 13:19:49 -0500
Subject: [PATCH] Added GAF_SWITCH to GetAngle, inverting the function to get
 the caller's angle on the pointer instead.

---
 src/thingdef/thingdef_codeptr.cpp  | 13 ++++++++++---
 wadsrc/static/actors/actor.txt     |  2 +-
 wadsrc/static/actors/constants.txt |  6 ++++++
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 441ba4899..1b1c7b2cf 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -329,13 +329,19 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, GetDistance)
 // NON-ACTION function to get the angle in degrees (normalized to -180..180)
 //
 //==========================================================================
+enum GAFlags
+{
+	GAF_RELATIVE =			1,
+	GAF_SWITCH =			1 << 1,
+};
+
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, GetAngle)
 {
 	if (numret > 0)
 	{
 		assert(ret != NULL);
 		PARAM_SELF_PROLOGUE(AActor);
-		PARAM_BOOL(relative);
+		PARAM_INT(flags);
 		PARAM_INT_OPT(ptr) { ptr = AAPTR_TARGET; }
 
 		AActor *target = COPY_AAPTR(self, ptr);
@@ -346,9 +352,10 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, GetAngle)
 		}
 		else
 		{
-			DVector3 diff = self->Vec3To(target);
+			DVector3 diff = (flags & GAF_SWITCH) ? target->Vec3To(self) : self->Vec3To(target);
 			DAngle angto = diff.Angle();
-			if (relative) angto = deltaangle(self->Angles.Yaw, angto);
+			DAngle yaw = (flags & GAF_SWITCH) ? target->Angles.Yaw : self->Angles.Yaw;
+			if (flags & GAF_RELATIVE) angto = deltaangle(yaw, angto);
 			ret->SetFloat(angto.Degrees);
 		}
 		return 1;
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 901d7a553..cb6ff4d93 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -41,7 +41,7 @@ ACTOR Actor native //: Thinker
 	native bool IsPointerEqual(int ptr_select1, int ptr_select2);
 	native int	CountInv(class<Inventory> itemtype, int ptr_select = AAPTR_DEFAULT);
 	native float GetDistance(bool checkz, int ptr = AAPTR_DEFAULT);
-	native float GetAngle(bool relative, int ptr = AAPTR_DEFAULT);
+	native float GetAngle(int flags, int ptr = AAPTR_DEFAULT);
 	native float GetZAt(float px = 0, float py = 0, float angle = 0, int flags = 0, int pick_pointer = AAPTR_DEFAULT);
 	native int GetSpawnHealth();
 	native int GetGibHealth();
diff --git a/wadsrc/static/actors/constants.txt b/wadsrc/static/actors/constants.txt
index 7b75b481d..46e810a7f 100644
--- a/wadsrc/static/actors/constants.txt
+++ b/wadsrc/static/actors/constants.txt
@@ -652,3 +652,9 @@ enum
 	BT_USER3		= 1<<23,
 	BT_USER4		= 1<<24,
 };
+// Flags for GetAngle
+enum
+{
+	GAF_RELATIVE =			1,
+	GAF_SWITCH =			1 << 1,
+};
\ No newline at end of file