float fOrient = GetFacing( GetFirstPC() -90.0 );

##</code><code>##

float fOrient = GetFacing( GetFirstPC() ) - 90.0;

##</code><code>##

my %game = qw{E 0.0 N 90.0 W 180.0 S 270.0};

for (qw{N E S W}) {
    my $real = (360 + 90 - $game{$_}) % 360;
    printf "game: %s = %5.1f; real: %5.1f\n" => $_, $game{$_}, $real;
} 

##</code><code>##

game: N =  90.0; real:   0.0
game: E =   0.0; real:  90.0
game: S = 270.0; real: 180.0
game: W = 180.0; real: 270.0

##</code><code>##

float fOrient = IntToFloat(
    (360 + 90 - FloatToInt(GetFacing(GetFirstPC()))) % 360
);