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Merged
QuLogic merged 4 commits into from
Sep 26, 2025
Merged

pdf: Improve text with characters outside embedded font limits #30512

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b70fb88
pdf: Improve text with characters outside embedded font limits
QuLogic Sep 3, 2025
1c4af68
pdf: Correct Unicode mapping for out-of-range font chunks
QuLogic Sep 3, 2025
6cedcf7
TST: Add emoji to multi-font text
QuLogic Sep 3, 2025
c908bbf
DOC: Add a release note for PDF font embedding fixes
QuLogic Sep 19, 2025
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3 changes: 3 additions & 0 deletions doc/api/next_api_changes/deprecations/30512-ES.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
``PdfFile.multi_byte_charprocs``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
... is deprecated with no replacement.
10 changes: 10 additions & 0 deletions doc/release/next_whats_new/pdf_fonts.rst
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@@ -0,0 +1,10 @@
Improved font embedding in PDF
------------------------------

Both Type 3 and Type 42 fonts (see :ref:`fonts` for more details) are now
embedded into PDFs without limitation. Fonts may be split into multiple
embedded subsets in order to satisfy format limits. Additionally, a corrected
Unicode mapping is added for each.

This means that *all* text should now be selectable and copyable in PDF viewers
that support doing so.
19 changes: 19 additions & 0 deletions lib/matplotlib/backends/_backend_pdf_ps.py
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Expand Up @@ -205,6 +205,25 @@ def track_glyph(
self.used.setdefault((font.fname, subset), {})[subset_charcode] = glyph
return (subset, subset_charcode)

def subset_to_unicode(self, index: int,
charcode: CharacterCodeType) -> CharacterCodeType:
"""
Map a subset index and character code to a Unicode character code.

Parameters
----------
index : int
The subset index within a font.
charcode : CharacterCodeType
The character code within a subset to map back.

Returns
-------
CharacterCodeType
The Unicode character code corresponding to the subsetted one.
"""
return index * self.subset_size + charcode


class RendererPDFPSBase(RendererBase):
# The following attributes must be defined by the subclasses:
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