Applied proper fix from jaMME for lines disappearing at certain angles (

#214)

See entdark/jaMME@4dcef10

(cherry picked from commit 41af0cd)

Co-authored-by: Ensiform <ensiform@gmail.com>

codemp/client/FxPrimitives.cpp

@@ -750,6 +750,30 @@ CLine::CLine(void)
 	mRefEnt.reType = RT_LINE;
 }
 
+//----------------------------
+bool CLine::Cull( void )
+{
+	vec3_t	dir;
+
+	VectorSubtract( mOrigin1, theFxHelper.refdef->vieworg, dir );
+
+	//Check if it's in front of the viewer
+	if ( (DotProduct( theFxHelper.refdef->viewaxis[0], dir )) >= 0 )
+	{
+		return false;	//don't cull
+	}
+
+	VectorSubtract( mOrigin2, theFxHelper.refdef->vieworg, dir );
+
+	//Check if it's in front of the viewer
+	if ( (DotProduct( theFxHelper.refdef->viewaxis[0], dir )) >= 0 )
+	{
+		return false;
+	}
+
+	return true; //all points behind viewer
+}
+
 //----------------------------
 void CLine::Draw(void)
 {

codemp/client/FxPrimitives.h

@@ -401,6 +401,7 @@ class CLine : public CParticle
 	virtual void Die() {}
 
 	virtual bool Update();
+	virtual bool Cull();
 
 	inline void SetOrigin2( vec3_t org2 )	{ VectorCopy( org2, mOrigin2 ); }
 };