It's a library to do svg.transforms.
It's been on a list of things to do for years, and I haven't implemented it, because I don't need it, and making a library you don't use is silly. But since nobody else is implementing this, even though it's perfectly simple, well, I did it anyway. Anger-Driven Development is a thing. :-D
You are welcome.
I'm already looking for someone to take over this, and I haven't even started writing code. You can take over svg.path too, I don't use it anymore either.
You make transformation matrices with the following commands:
* svg.transform.translate_matrix(tx, ty=0): Returns a matrix that will translate in x and y * svg.transform.scale_matrix(sx, sy=None): Returns a matrix that will scale in x and y * svg.transform.rotate_matrix(r, cx=0, cy=0): Returns a matrix that will rotate, with optional offset * svg.transform.skewx_matrix(ax): Returns a matrix that will skew in the x axis * svg.transform.skewy_matrix(ay): Returns a matrix that will skew in the y axis * svg.transform.matrix_matrix(a, b, c, d, e, f): Returns a free form translation matrix
For example like this:
>>> from svg import transform
>>>
>>> transform.translate_matrix(5, 8)
array([[ 1, 0, 5],
[ 0, 1, 10],
[ 0, 0, 1]])
You use this matrix by applying a matrix multiplication:
>>> from array import array
>>>
>>> old_x = 10
>>> old_y = 10
>>>
>>> res = transform.translate_matrix(5, 8) @ array("f", [old_x, old_y, 1])
>>> new_x = res[0]
>>> new_y = res[1]
>>> new_x, new_y
15.0, 18.0
You can also create transformation matrices directly from the SVG transform attributes:
>>> transform.parse("translate(-10 -20) scale(2) rotate(45) translate(5 10)")
array([[ 1.05064398, -1.70180705, -21.7648506 ],
[ 1.70180705, 1.05064398, -0.98452498],
[ 0. , 0. , 1. ]])