MutatorMath started out with its own reader and writer for designspaces. Since then the use of designspace has broadened and it would be useful to have a reader and writer that are independent of a specific system.

DesignSpaceDocument Object

An object to read, write and edit interpolation systems for typefaces.

• Originally written for MutatorMath.
• Also used in fontTools.varlib.
• Define sources, axes and instances.
• Not all values might be required by all applications.

A couple of differences between things that use designspaces:

• Varlib does not support anisotropic interpolations.
• The goals of Varlib and MutatorMath are different, so not all attributes are always needed.
• FDK ?

The DesignSpaceDocument object can read and write .designspace data. It imports the axes, sources and instances to very basic "descriptor" objects that store the data in attributes. Data is added to the document by creating such descriptor objects, filling them with data and then adding them to the document. This makes it easy to integrate this object in different contexts.

The DesignSpaceDocument object can be subclassed to work with different objects, as long as they have the same attributes.

The object does not do any validation.

from designspaceDocument import DesignSpaceDocument
doc = DesignSpaceDocument()
doc.read("some/path/to/my.designspace")
doc.axes
doc.sources
doc.instances

Source descriptor object attributes

• path: string. Path to the source file. MutatorMath + Varlib.
• name: string. Unique identifier name of the source, used to identify it if it needs to be referenced from elsewhere in the document. MutatorMath.
• location: dict. Axis values for this source. MutatorMath + Varlib
• copyLib: bool. Indicates if the contents of the font.lib need to be copied to the instances. MutatorMath.
• copyInfo bool. Indicates if the non-interpolating font.info needs to be copied to the instances. MutatorMath.
• copyGroups bool. Indicates if the groups need to be copied to the instances. MutatorMath.
• copyFeatures bool. Indicates if the feature text needs to be copied to the instances. MutatorMath.
• muteKerning: bool. Indicates if the kerning data from this source needs to be muted (i.e. not be part of the calculations). MutatorMath.
• muteInfo: bool. Indicated if the interpolating font.info data for this source needs to be muted. MutatorMath.
• mutedGlyphNames: list. Glyphnames that need to be muted in the instances. MutatorMath.
• familyName: string. Family name of this source. Though this data can be extracted from the font, it can be efficient to have it right here. Varlib.
• styleName: string. Style name of this source. Though this data can be extracted from the font, it can be efficient to have it right here. Varlib.

doc = DesignSpaceDocument()
s1 = SourceDescriptor()
s1.path = masterPath1
s1.name = "master.ufo1"
s1.copyLib = True
s1.copyInfo = True
s1.copyFeatures = True
s1.location = dict(weight=0)
s1.familyName = "MasterFamilyName"
s1.styleName = "MasterStyleNameOne"
s1.mutedGlyphNames.append("A")
s1.mutedGlyphNames.append("Z")
doc.addSource(s1)

Instance descriptor object

• path: string. Path to the instance file, which may or may not exist. MutatorMath
• name: string. Unique identifier name of the instance, used to identify it if it needs to be referenced from elsewhere in the document.
• location: dict. Axis values for this source. MutatorMath + Varlib.
• familyName: string. Family name of this instance. MutatorMath + Varlib.
• styleName: string. Style name of this source. MutatorMath + Varlib.
• postScriptFontName: string. Postscript FontName for this instance. MutatorMath.
• styleMapFamilyName: string. StyleMap FamilyName for this instance. MutatorMath.
• styleMapStyleName: string. StyleMap StyleName for this instance. MutatorMath.
• glyphs: dict for special master definitions for glyphs. If glyphs need special masters (to record the results of executed rules for example). MutatorMath.
• kerning: bool. Indicates if this instance needs its kerning calculated. MutatorMath.
• info: bool. Indicated if this instance needs the interpolating font.info calculated.

i2 = InstanceDescriptor()
i2.path = instancePath2
i2.familyName = "InstanceFamilyName"
i2.styleName = "InstanceStyleName"
i2.name = "instance.ufo2"
# anisotropic location 
i2.location = dict(weight=500, width=(400,300))
i2.postScriptFontName = "InstancePostscriptName"
i2.styleMapFamilyName = "InstanceStyleMapFamilyName"
i2.styleMapStyleName = "InstanceStyleMapStyleName"
glyphMasters = [dict(font="master.ufo1", glyphName="BB", location=dict(width=20,weight=20)), dict(font="master.ufo2", glyphName="CC", location=dict(width=900,weight=900))]
glyphData = dict(name="arrow", unicodeValue=1234)
glyphData['masters'] = glyphMasters
glyphData['note'] = "A note about this glyph"
glyphData['instanceLocation'] = dict(width=100, weight=120)
i2.glyphs['arrow'] = glyphData
i2.glyphs['arrow2'] = dict(mute=False)
doc.addInstance(i2)

Axis descriptor object

• tag: string. Four letter tag for this axis. Some might be registered at the OpenType specification.
• name: string. Name of the axis as it is used in the location dicts. MutatorMath + Varlib.
• labelNames: dict. When defining a non-registered axis, it will be necessary to define user-facing readable names for the axis. Keyed by xml:lang code. Varlib.
• minimum: number. The minimum value for this axis. MutatorMath + Varlib.
• maximum: number. The maximum value for this axis. MutatorMath + Varlib.
• default: number. The default value for this axis, i.e. when a new location is created, this is the value this axis will get. MutatorMath + Varlib.
• map: list of input / output values that can describe a warp of user space to designspace coordinates. If no map values are present, it is assumed it is [(minimum, minimum), (maximum, maximum)].laat iklaa Varlib.

a1 = AxisDescriptor()
a1.minimum = 0
a1.maximum = 1000
a1.default = 0
a1.name = "weight"
a1.tag = "wght"
a1.labelNames[u'fa-IR'] = u"قطر"
a1.labelNames[u'en'] = u"Wéíght"
a1.map = [(0.0, 10.0), (401.0, 66.0), (1000.0, 990.0)]

Document xml structure

• The axes element contains one or more axis elements.
• The sources element contains one or more source elements.
• The instances element contains one or more instance elements.

<?xml version='1.0' encoding='utf-8'?>
<designspace format="3">
	<axes>
		<!-- define axes here -->
		<axis../>
		</axes>
	<sources>
		<!-- define masters here -->
		<source../>
	</sources>
	<instances>
		<!-- define instances here -->
		<instance../>
	</instances>
</designspace>

1. axis element

• Define a single axis
• Child element of axes

Attributes

• name: required, string. Name of the axis that is used in the location elements.
• tag: required, string, 4 letters. Some axis tags are registered in the OpenType Specification.
• minimum: required, number. The minimum value for this axis.
• maximum: required, number. The maximum value for this axis.
• default: required, number. The default value for this axis.

<axis name="weight" tag="wght" minimum="-1000" maximum="1000 default="0">

1.1 labelname element

• Defines a human readable name for UI use.
• Optional for non-registered axis names.
• Can be localised with xml:lang
• Child element of axis

Attributes

• xml:lang: required, string. XML language definition

Value

• The natural language name of this axis.

<labelName xml:lang="fa-IR">قطر</labelName>
<labelName xml:lang="en">Wéíght</labelName>

1.2 map element

• Defines a single node in a series of input value / output value pairs.
• Together these values transform the designspace.
• Child of axis element.

<map input="0.0" output="10.0" />
<map input="401.0" output="66.0" />
<map input="1000.0" output="990.0" />

2. source element

• Defines a single font that contributes to the designspace.
• Child element of sources

Attributes

• familyname: optional, string. The family name of the source font. While this could be extracted from the font data itself, it can be more efficient to add it here.
• stylename: optional, string. The style name of the source font.
• name: required, string. A unique name that can be used to identify this font if it needs to be referenced elsewhere.
• filename: required, string. A path to the source file, relative to the root path of this document. The path can be at the same level as the document or lower.

2.1 lib element

• <lib copy="1" />
• Child element of source
• Defines if the instances can inherit the data in the lib of this source.
• MutatorMath only

2.2 info element

• <info copy="1" />
• Child element of source
• Defines if the instances can inherit the non-interpolating font info from this source.
• MutatorMath only

2.3 features element

• <features copy="1" />
• Defines if the instances can inherit opentype feature text from this source.
• Child element of source
• MutatorMath only

2.4 glyph element

• Can appear in source as well as in instance elements.
• In a source element this states if a glyph is to be excluded from the calculation.
• MutatorMath only

Attributes

• <glyph mute="1" name="A"/>
• mute: optional, number, andts

2.5.1dimension element

• Child element of location

Attributes

• name: required, string. Name of the axis.
• xvalue: required, number. The value on this axis.
• yvalue: optional, number. Separate value for anisotropic interpolations.

Example

<source familyname="MasterFamilyName" filename="masters/masterTest1.ufo" name="master.ufo1" stylename="MasterStyleNameOne">
	<lib copy="1" />
   <features copy="1" />
	<info copy="1" />
   	<glyph mute="1" name="A" />
   <glyph mute="1" name="Z" />
   <location>
      <dimension name="width" xvalue="0.000000" />
      <dimension name="weight" xvalue="0.000000" />
   </location>
</source>

3. instance element

• Defines a single font that can be calculated with the designspace.
• Child element of instances
• For use in Varlib the instance element really only needs the names and the location. The glyphs element is not required.
• MutatorMath uses the glyphs element to describe how certain glyphs need different masters, mainly to describe the effects of conditional rules in Superpolator.

Attributes

• familyname: required, string. The family name of the instance font. Corresponds with font.info.familyName
• stylename: required, string. The style name of the instance font. Corresponds with font.info.styleName
• name: required, string. A unique name that can be used to identify this font if it needs to be referenced elsewhere.
• filename: string. Required for MutatorMath. A path to the instance file, relative to the root path of this document. The path can be at the same level as the document or lower.
• postscriptfontname: string. Optional for MutatorMath. Corresponds with font.info.postscriptFontName
• stylemapfamilyname: string. Optional for MutatorMath. Corresponds with styleMapFamilyName
• stylemapstylename : string. Optional for MutatorMath. Corresponds with styleMapStyleName

<instance familyname="InstanceFamilyName" filename="instances/instanceTest2.ufo" name="instance.ufo2" postscriptfontname="InstancePostscriptName" stylemapfamilyname="InstanceStyleMapFamilyName" stylemapstylename="InstanceStyleMapStyleName" stylename="InstanceStyleName">
<location>
	<dimension name="width" xvalue="400" yvalue="300" />
   <dimension name="weight" xvalue="500" />
</location>
<glyphs>
	<glyph name="arrow2" />
   <glyph name="arrow" unicode="0x4d2">
   <location>
   		<dimension name="width" xvalue="100" />
      	<dimension name="weight" xvalue="120" />
	</location>
   <note>A note about this glyph</note>
   <masters>
   		<master glyphname="BB" source="master.ufo1">
		   <location>
				<dimension name="width" xvalue="20" />
				<dimension name="weight" xvalue="20" />
			</location>
		</master>
	</masters>
	</glyph>
   </glyphs>
   <kerning />
   <info />
</instance>

Notes on this document

Second version. The package is rather new and changes are to be expected.