like cmap, or glyf or OTL tables, we need to respect lazy=False flag and decompile everything upfront, also we want to add an ensureDecompiled method (called by TTFont.ensureDecompiled) to allow loading everything in one go even when a font had been opened lazily.
In the upcoming draft of COLR spec, PaintSweepGradient's startAngle/endAngle are encoded with a +1.0 bias to allow for representation of a full +360° positive angle. Normal F2Dot14-fraction-of-half-circle angles can only represent angles between -360 <= angle < +360
This is a breaking change and will need to be coordinated with rendering implementations (at least FreeType/Skia).
though we still emit the empty <Map index=.../> elements; they help identify chunks of delta-set indices, and define the length of the array upon loading from XML
we tell GzipFile to write the MTIME field to zero so that the compressed output is reproducible and doesn't change depending on when the data is compressed.
4294967295 (0xFFFFFFFF in decimal form) is not very memorable.
Still, using hex notation for all VarIndexBases would make the non-default values less readable (when interpreted as an index into the DeltaSetIndexMap array, decimal makes more sense).
Since 0xFFFFFFFF means 'no variation data', it makes sense to omit it from the ttx dump and write an empty <VarIndexBase/> element with no value.
We also allow to build Var tables without needing to pass "VarIndexBase": 0xFFFFFFFF in the source dict.
This updates fonttools to match the latest draft COLRv1 spec at https://github.com/googlefonts/colr-gradients-spec/pull/290
Summary of changes:
- Added 8 new PaintScale* tables: with/without centers, uniform vs non-uniform
- Added *AroundCenter variants to PaintRotate and PaintSkew (default versions no longer have centerX/Y defaulting to origin)
- PaintRotate, PaintSkew and PaintComposite formats re-numbered
This is a breaking change (but the COLRv1 API was already marked as unstable and subject to change)
The changes in this PR are meant to match the changes from the COLRv1 draft spec at:
https://github.com/googlefonts/colr-gradients-spec/pull/302
* Replaced all from ...py23 import * with explicit name imports, or removed completely when possible.
* Replaced tounicode() with tostr()
* Changed all BytesIO ans StringIO imports to from io import ..., replaced all UnicodeIO with StringIO.
* Replaced all unichr() with chr()
* Misc minor tweaks and fixes
