Adding frequently used function to compiles.

SQF/dayz_code/compile/fn_fieldOfView.sqf

@@ -0,0 +1,39 @@
+// This function checks to see if a potential zombie spawn position is in the field of view of near players.
+
+private ["_isOk","_zPos","_fov","_safeDistance","_farDistance","_xasl","_eye","_ed","_deg"];
+
+_isOk = true;
+_zPos = +(_this select 0);
+if (count _zPos < 3) exitWith {
+	diag_log format["%1::fn_fieldOfView illegal pos %2", __FILE__, _zPos];
+	false
+};
+_zPos = ATLtoASL _zPos;
+_fov = _this select 1; // players half field of view
+_safeDistance = _this select 2; // minimum distance. closer is wrong
+_farDistance = _this select 3; // distance further we won't check
+_zPos set [2, (_zPos select 2) + 1.7];
+{
+	_xasl = getPosASL _x;
+	if (_xasl distance _zPos < _farDistance) then {
+		if (_xasl distance _zPos < _safeDistance) then {
+			_isOk = false;
+		} else {
+			_eye = eyePos _x; // ASL
+			_ed = eyeDirection _x;
+			_ed = (_ed select 0) atan2 (_ed select 1);
+			_deg = [_xasl, _zPos] call BIS_fnc_dirTo;
+			_deg = (_deg - _ed + 720) % 360;
+			if (_deg > 180) then { _deg = _deg - 360; };
+			if ((abs(_deg) < _fov) && {( // in right angle sector?
+					(!(terrainIntersectASL [_zPos, _eye]) // no terrain between?
+					&& {(!(lineIntersects [_zPos, _eye]))}) // and no object between?
+				)}) then {
+				_isOk = false;
+			};
+		};
+	};
+	if (!_isOk) exitWith {false};
+} forEach playableUnits;
+
+_isOk