Transform from bounding box via scripting?

Scripting
1

How can I transform horizontally so that the left edge stays aligned? As in how does the applyTransform() work and is it possible to set a transform origin?

2

You need to set up the transformation: It is not always obvious how that works but google will help you.

Here is an example that scales 200% from X=200. It’s kind of like move the hole thing away from the origin, then scale (or rotate) and then move it back.

from Foundation import NSAffineTransform
Transform = NSAffineTransform.transform()

Transform.translateXBy_yBy_(200, 0)
Transform.scaleBy_(2)
Transform.translateXBy_yBy_(200, 0)
Layer.applyTransform(Transform.transformStruct())
1 Like
3

Here is the method I use; instructions in the comments:

import math

def transform(shiftX=0.0, shiftY=0.0, rotate=0.0, skew=0.0, scale=1.0):
	"""
	Returns an NSAffineTransform object for transforming layers.
	Apply an NSAffineTransform t object like this:
		Layer.transform_checkForSelection_doComponents_(t,False,True)
	Access its transformation matrix like this:
		tMatrix = t.transformStruct() # returns the 6-float tuple
	Apply the matrix tuple like this:
		Layer.applyTransform(tMatrix)
		Component.applyTransform(tMatrix)
		Path.applyTransform(tMatrix)
	Chain multiple NSAffineTransform objects t1, t2 like this:
		t1.appendTransform_(t2)
	"""
	myTransform = NSAffineTransform.transform()
	if rotate:
		myTransform.rotateByDegrees_(rotate)
	if scale != 1.0:
		myTransform.scaleBy_(scale)
	if not (shiftX == 0.0 and shiftY == 0.0):
		myTransform.translateXBy_yBy_(shiftX,shiftY)
	if skew:
		skewStruct = NSAffineTransformStruct()
		skewStruct.m11 = 1.0
		skewStruct.m22 = 1.0
		skewStruct.m21 = math.tan(math.radians(skew))
		skewTransform = NSAffineTransform.transform()
		skewTransform.setTransformStruct_(skewStruct)
		myTransform.appendTransform_(skewTransform)
	return myTransform
2 Likes
4

There is a addition to NSAffineTransform available in Glyphs:

- (void)shearXBy:(CGFloat)xShear yBy:(CGFloat)yShear;

that can be used in python like this:

myTransform.shearXBy_yBy_(skewX, skewY)
2 Likes