MutatorMath 3.0.1

License

The MutatorMath package is published under the BSD-3 license.

Dependencies

The basic Mutator and Location objects will run on any standard Python 2.7 or higher distribution, and is been tested on Python 3.5 or higher.

The UFO processing tools in MutatorMath need some additional libraries.

MutatorMath terminology

• designspace: abstract Euclidian space with any number of dimensions.

• axis: A dimension in the designspace. Dimension names can be descriptive, for instance x, y, width, weight, pop, snap.

• location: Coordinates of a point in the designspace stored as a dictionary of named dimensions. For instance Location(x=0) and Location(x=10) are in the same dimension, whereas Location(snap=10) is not. There will be implementation limits on the number of dimensions, but theoretically there is no limit.

• split location or ambivalent location: A location in which one or more dimensions have a 2-tuple rather than a single value. This is used to describe anisotropic locations. For instance Location(weight=(50, 60)) means the horizontal value is 50, the vertical value is 60. Support for anisotropic coordinates is only 2 dimensional.

• origin: A special location at which all dimension values are 0. Unnamed dimensions are assumed to be zero. Location() is at the origin.

• on-axis: A location with a single non-zero axis value. Location(width=1000) is considered to be on-axis.

• off-axis: A location with more than one non-zero axis value. Location(width=1000, weight=1000) is considered to be off-axis.

• bias: A design space vector that translates all masters and instances.

• arithmetic support

  • objects that offer arithmetic behavior

  • objects that respond to +, -, * and /

  • objects with __add__, __sub__, __mul__, __rmul__, __div__ and __rdiv__ methods

• master: an arithmetic object that provides the input data.

• neutral: a master inserted at the origin

• instance: an object calculated at a specific location, same class as the master.

An explanation with colorful graphs of how the MutatorMath calculates the factors.

Building a Mutator

A convenient Mutator builder function buildMutator() accepts a list of (location, object) pairs. Internally it sorts the neutral / on / off axis masters and calculates the bias.

• Master locations must not overlap.

• For a more in-depth examples of building Mutator objects, read the doctests.

Designspace document

The requirements for a UFO designspace will differ from project to project. The location of the masters and instances, special wishes for kerning and specific glyphs etc. This package provides tools to read and write a description of a designspace to XML. Such a file stores all information necessary: which source UFOs, where to insert them, which glyphs to generate, which instances etc.

• A designspace document can be processed by a simple python build script. (See buildExample.py). That makes it possible to build instances on remote computers, as part of cron jobs etc.

• Examples and tests of the reader and writer can be found in the test/ufo/ directory.

• MutatorMath proposes the .designspace extension.

Designspace XML structure

A .designspace file contains all data needed for setting up interpolations between a number of master UFOs. A detailed description of the designspace format here: designspace file format

Legal

• Superpolator is a registered trademark of LettError Type & Typography, More on Superpolator.com

Thanks

• MutatorMath was made possible with kind support from the Adobe Type Team.

• Thanks to TypeSupply for writing FontMath.

• Thanks to TypeMyType for writing RoboFont.