designspace_relocation.py

"""
This is very barebones, but it allows changing one or several locations 
within a designspace while preerving an identical output.
(hey, it's hard to plan a designspace exactly right from the start :)

ie. changing a source location from weight:1200 to weight:1000 will recalculate all the other locations
so that the resulting instances remain the same as before.

Set your relocation_map below.
"""

# ----------------------------------------

import pathlib

from mutatorMath.objects.mutator import buildMutator
from mutatorMath.objects.location import Location

from ufoProcessor import DesignSpaceDocument

# ----------------------------------------

DESIGN_SPACE_PATH = "../30 ufos/sources/Dulux-A.designspace"

"""
This list should map tuples of existing locations in the designspace to their desired new locations,
-> (existing_location, desired_location)
If you want a existing location to remain the unchanged, it should be featured in this list, 
with existing location and desired location being the same
-> (existing_location, exiting_location) 
Any location, source or instance, not present in this list will be recalculated.
"""

relocation_map = [
    (Location(weight=0, width=0), Location(weight=0, width=0)),
    (Location(weight=1200, width=0), Location(weight=1000, width=0)),
    (Location(weight=0, width=1000), Location(weight=0, width=1000)),
    (Location(weight=1000, width=1000), Location(weight=1000, width=1000)),
]

round_new_locations = True

# ----------------------------------------

def offset_location(source_or_instance, offset_space, rounded=False, verbose=True):
    offset = offset_space.makeInstance(source_or_instance.location)
    new_loc = Location(**source_or_instance.location) + offset
    if round_location:
        new_loc = round_location(new_loc)
    if verbose:
        print(f"offseting {source_or_instance.familyName}-{source_or_instance.styleName}:")
        print(f"{Location(**source_or_instance.location)} -> {new_loc}")
        print()

    source_or_instance.location = new_loc

def round_location(location):
    data = {a: round(v) for a, v in location.items()}
    return Location(**data)

# ----------------------------------------

root_path = pathlib.Path(__file__).parent
input_path = root_path / DESIGN_SPACE_PATH

offset_loc = [(old_loc, new_loc-old_loc) for old_loc, new_loc in relocation_map]
bias, offset_space = buildMutator(offset_loc)

original_space = DesignSpaceDocument()
original_space.read(DESIGN_SPACE_PATH)

print("Relocating sources")
for source in original_space.sources:
    offset_location(source, offset_space, rounded=round_new_locations)

print("Relocating instances")
for instance in original_space.instances:
    offset_location(instance, offset_space, rounded=round_new_locations)

output_name = input_path.stem + "_relocated" + input_path.suffix
output_path = input_path.parent / output_name

original_space.write(output_path)
print(f"Saved {output_path.name}.")

Should be tested with the upcoming DS5 update for ufoProcessor: https://github.com/LettError/ufoProcessor/tree/ds5