GDScript: Bit/flag functions

##########################
### Bit/flag functions ###
##########################

# You need to create a variable like this (in this example, there are four flags):
#   var flags = 0b0000
#
# Then you need to create some constants or an enum for these flags.
# As an enum:
#   enum STATES { walking = 1 << 0, running = 1 << 1, rising = 1 << 2, falling = 1 << 3 }
# Or as constants:
#   const STATE_WALKING = 1 << 0
#   const STATE_RUNNING = 1 << 1
#   ...



# USE CASE: if check_flag(bitfield_variable, flag_constant): ...
# e.g.
# if check_flag(statebits, STATES.walking):

static func check_flag(bitfield : int, flag : int, verbose : bool = false):
    var out = bool(bitfield & flag)
    if verbose: print(out)
    return out


# USE CASE: bitfield_variable = toggle_flag(bitfield_variable, flag_constant)
# e.g.
# statebits = toggle_flag(statebits, STATES.walking)

static func toggle_flag(bitfield : int, flag : int):
    if (bitfield & flag): bitfield = bitfield - flag
    else: bitfield = bitfield | flag
    print(bitfield)
    return bitfield


# USE CASE: bitfield_variable = set_flag(bitfield_variable, flag_constant, boolean)
# e.g.
# statebits = set_flag(statebits, STATE.walking, true)

static func set_flag(bitfield : int, flag : int, switch : bool):
    if switch: # setting bit to 1
        if !(bitfield & flag):  bitfield = bitfield | flag
    else: # setting bit to 0
        if (bitfield & flag):    bitfield = bitfield - flag
    return bitfield