baender
commented
2 years ago To get the bounding box of a clone, I figured that applying the inverse transformation of the template element and then applying the clone´s tranformation is the way to go.
Doing so gives me the right result for the clone´s bounding box, no matter what the order of the elements within the xml file is. However, calculating the bounding box of the original element is influenced by the existance of a clone below the element.
Even though my results seem to be correct, the issue with the incorrect bounding box seems to be persistant.
import svgelements
# svgFileName = "path/to/svg"
layout = svgelements.SVG.parse(
source = svgFileName,
reify = True,
ppi = svgelements.svgelements.DEFAULT_PPI,
width = 1,
height = 1,
color = "black",
transform = None,
context = None
)
template = layout.get_element_by_id("rect2728")
cloneElement = layout.get_element_by_id("use2810")
transformMatrixTemplate = svgelements.Matrix(template.values["transform"])
transformMatrixClone = svgelements.Matrix(cloneElement.values["transform"])
clone = template * transformMatrixTemplate.inverse() * transformMatrixClone
[round(value, 3) for value in template.bbox()]
[round(value, 3) for value in clone.bbox()]
# Result is incorrect; happens when `rect` comes BEFORE `use`
# [40.0, 120.0, 1880.0, 200.0]
# [40.0, 120.0, 1880.0, 200.0]
# Result is correct; happens when `rect` comes AFTER `use`
# [40.0, -160.0, 1880.0, -80.0]
# [40.0, 120.0, 1880.0, 200.0]
tatarize
I am interested in the bounding box of various clones of an element. While using svgelements with SVGs created in inkscape, I stumbled upon an issue.
How to reproduce
Store the xml code as .svg and run the Python code.
What happens
When creating a clone of an element, the
.get_element_by_id()method applies the clone transform to the original element, depending on the order of the two elements. If one manually moves therectelement after theuseelement, the method works correctly and the clone transform is not applied to the original element. However, when creating a clone, theuseelement is always added after therectelement and therefore forces this issue to occur.What one expects to happen
When using the method
.get_element_by_id()it should not matter whether the element has a clone or not. The clone transform should not be applied at all, no matter the relative order of the two elements.What might be happening
The
xlink:hrefattribute of theuseelement holds the original element´s ID and might be parsed at some point. Thetransformmight be mistakenly stored with the original element. Changing the order of the two elements might overwrite thetransformstring of the original element.System Python 3.6.8 svgelements 1.6.5