We already filter len(layers)==1 out upfront, but these can sneak in after the layer reuse code when input contains two base glyphs that refer to the same list of layers. This ensure that duplicate base glyphs get the same PaintColrLayers, rather than a wrapper PaintColrLayers of length=1 pointing to the underlying shared PaintColrLayer...
this test currently fails; currently the second, third, etc. base glyphs with the same layers gets a unique PaintColrLayers with NumLayers:1 that in turn contains the shared PaintColrLayers. They should instead all share the same PaintColrLayers. Fix in the next commit
Importing freetype at import time breaks the Read the Docs build. Solves
the issue by raising an error in __init__ as fontTools.ttLib.woff2 does,
while avoiding adding an extra line to Doc/docs-requirements.txt.
Surprisingly I found Preview.app can still display PGM images. While
somewhat legacy, it's a super straightforward format to (de)serialize.
The images are scaled to 50x50 px and only consume 5KB in total. Makes
more sense to human being than the previous base64-encoded zlib
compressed data, plus we don't have to add pillow as a dependency.
Eliminates the assumption of any specific metrics from the pen. It still
gives some image without giving any parameters, thus it should be a good
starting point for new users.
There are possibilities that the rendering results may change among
FreeType versions. I've already used the PSNR comparison for cubic
vs quadratic testing, so I applied the same technique and threshold to
all rendering tests to relax assertions. Also handles the case that
MSE becomes zero. Optional dependencies are not needed for the tests.
After experimenting with uharfbuzz for a while, I found out it was hard
to handle top-to-bottom texts, so I gave up an idea to put an ascender
or a descender value in the arguments. Instead, I simply expose 'offset',
'width' and 'height', which is way more straightforward than the
previous design.
In addition, 'contain' option is added to easily compensate and render
glyphs such as combining accents or excessively tall letters.
