helpers.py

"""
Provides various helper functions.
"""

import math

def remap( x, oMin, oMax, nMin, nMax ): # thanks stackoverflow.com/a/15537393
    #range check
    if oMin == oMax:
        print("Warning: Zero input range")
        return None

    if nMin == nMax:
        print("Warning: Zero output range")
        return None

    #check reversed input range
    reverseInput = False
    oldMin = min( oMin, oMax )
    oldMax = max( oMin, oMax )
    if not oldMin == oMin:
        reverseInput = True

    #check reversed output range
    reverseOutput = False
    newMin = min( nMin, nMax )
    newMax = max( nMin, nMax )
    if not newMin == nMin :
        reverseOutput = True

    portion = (x-oldMin)*(newMax-newMin)/(oldMax-oldMin)
    if reverseInput:
        portion = (oldMax-x)*(newMax-newMin)/(oldMax-oldMin)

    result = portion + newMin
    if reverseOutput:
        result = newMax - portion

    return result

'''
Given a value and power, this raises the value
to the power, then negates it if the value was
originally negative.
'''

def raiseKeepSign(value, power):
    newValue = value ** power

    if (value < 0 and newValue > 0):
        return newValue * -1
    else:
        return value ** power

'''
Given a Cartesian x,y position, this 'snaps'
it to the nearest angle, in degrees (the
number of snappable angles is determined by
`divisions`). Intended to be used with joystick
values.
'''
def snap(divisions, x, y):
    if (x == 0):
        return 0

    result = round(math.atan2(y, x) / (2 * math.pi / divisions) + divisions, 0) % divisions

    return result * (360 / divisions)

'''
Maps a value onto a sin curve. Made for
the driving fuctions.
'''
def curve(value):
    return math.sin(value ** 2) * math.pi/2.6

'''
Rotates a vector in Caresian space.
'''
def rotateVector(x, y, angle):
    angle = math.radians(angle)
    cosA = math.cos(angle)
    sinA = math.sin(angle)
    return (x * cosA - y * sinA), (x * sinA + y * cosA)

def normalizeAngle(angle):
    '''Normalize angle to [-180,180]'''
    return ((angle + 180) % 360) - 180.0