Current-source PDF behavior ports

SourcePdfGradients.php translates svg2pdf.js 2.7 getGradientFill and
Gradient.getStops behavior. The C37 attribute/physical-state lowering in
ImagesC33/SourcePdfPreparation.php follows parseAttributes, applyAttributes,
Context, ImageNode and GeometryNode behavior. SourcePdfPaintContexts.php and
SourcePdfSymbols.php follow the same installed source. These PHP ports do
not invoke JavaScript, a browser, or a remote service at runtime.

The corresponding upstream svg2pdf.js license is retained below.

The MIT License (MIT)

Copyright (c) 2015-2023 yWorks GmbH
Copyright (c) 2013-2015 by Vitaly Puzrin


Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



SourcePdfText.php also ports the jsPDF 4.2.1 standard font selection and
Unicode/WinAnsi content-string encoding rules. The corresponding upstream
jsPDF license is retained below.

SourcePdfTextBidi.php and SourcePdfTextBidiData.php port the same installed
jsPDF Arabic parser and default Unicode Bidi Engine string pipeline. The
upstream Bidi Engine credits the work of Alex Shensis (@asthensis), under
the MIT License. Its retained Unicode type table is based on
mathiasbynens/unicode-8.0.0, as documented in the original jsPDF source.
These ports preserve that pinned source's behavior, rather than claiming
to implement a newer Unicode Bidi standard or browser SVG text shaping.

Copyright
(c) 2010-2025 James Hall, https://github.com/MrRio/jsPDF
(c) 2015-2025 yWorks GmbH, https://www.yworks.com/

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
