huey: Internal maintenance specification

The various color model we support will be concrete classes that share an interface defined in this base class.

# - - - - -   c l a s s   C o l o r M o d e l

class ColorModel:
    """Base class for color models.

      Exports:
        ColorModel ( modelName, labelList ):
          [ (modelName is the name of this model as a string) and
            (labelList is a sequence of three strings naming
            the parameters of this model) ->
              return a ColorModel object with those names ]
        .modelName:     [ as passed to constructor, read-only ]
        .labelList:     [ as passed to constructor, read-only ]

Functionally, a color model translates between a Color object (which internally uses RGB color space) and a trio of parameters that describe that color in the given model. The next two methods are the two conversions; see Section 7.2, “ColorModel.paramsToColor()” and Section 7.3, “ColorModel.colorToParams()”.

        .paramsToColor ( params ):
          [ params is a sequence of three numbers in [0,MAX_PARAM] ->
              return that color in self's model as a Color instance ]
        .colorToParams ( color ):
          [ color is a Color instance ->
              return color's parameters in self's model as a
              sequence of three numbers in [0,MAX_PARAM] ]

The class also contains two static methods used to convert between numbers in [0,MAX_PARAM] and floats in [0.0, 1.0]. See Section 7.4, “ColorModel.normalize(): Normalize an integer color parameter” and Section 7.5, “ColorModel.discretize(): Discretize an integer color parameter”.

        ColorModel.normalize(n):
           [ n is an int in [0,MAX_PARAM] ->
               return float(n)/MAX_PARAM ]
         ColorModel.discretize(n):
           [ n is a float in [0.0, 1.0] ->
               return int(n*MAX_PARAM) ]
    """