Improve varLib model algorithm.
This, basically means any varfont built that had an unusual master
configuration will change when rebuilt.
Here's a good test: a two-axis with 8 masters at unusual locations:
2-----------------5----------3
| |
| 7 |
| |
| 6 |
| |
| |
| |
0-----------4----------------1
Previously, the reach of master 3 (Black Extended) would
have started from A=.4, ie, the A position of master 4.
It now correctly starts from 0. Same thing with masters
after it. Ie, master 5 gets a span on the A axis from
0 to 1, whereas before it was getting from .4 to 1.
Previously, the on-axis masters always cut the space. They
don't anymore. That's more consistent, and fixes the main
issue Erik showed at TYPO Labs 2017. Same issue was also
causing the reach of master 3 to be limited, which I think
is the issue being discussed in the linked issue. Both should
be fixed.
It's hard to describe exactly what happened before / after.
Best to read the actual support values:
Before:
Sorted locations:
$ ./fonttools varLib.models 0,0 0,1 1,0 1,1 .4,0 .6,1 .5,.5 .7,.7
[{},
{'A': 0.4},
{'A': 1.0},
{'B': 1.0},
{'A': 1.0, 'B': 1.0},
{'A': 0.6, 'B': 1.0},
{'A': 0.5, 'B': 0.5},
{'A': 0.7, 'B': 0.7}]
Supports:
[{},
{'A': (0.0, 0.4, 1.0)},
{'A': (0.4, 1.0, 1.0)},
{'B': (0.0, 1.0, 1.0)},
{'A': (0.4, 1.0, 1.0), 'B': (0.0, 1.0, 1.0)},
{'A': (0.4, 0.6, 1.0), 'B': (0.0, 1.0, 1.0)},
{'A': (0.4, 0.5, 1.0), 'B': (0.0, 0.5, 1.0)},
{'A': (0.5, 0.7, 1.0), 'B': (0.5, 0.7, 1.0)}]
After:
$ ./fonttools varLib.models 0,0 0,1 1,0 1,1 .4,0 .6,1 .5,.5 .7,.7
Sorted locations:
[{},
{'A': 0.4},
{'A': 1.0},
{'B': 1.0},
{'A': 1.0, 'B': 1.0},
{'A': 0.6, 'B': 1.0},
{'A': 0.5, 'B': 0.5},
{'A': 0.7, 'B': 0.7}]
Supports:
[{},
{'A': (0, 0.4, 1.0)},
{'A': (0.4, 1.0, 1.0)},
{'B': (0, 1.0, 1.0)},
{'A': (0, 1.0, 1.0), 'B': (0, 1.0, 1.0)},
{'A': (0, 0.6, 1.0), 'B': (0, 1.0, 1.0)},
{'A': (0, 0.5, 1.0), 'B': (0, 0.5, 1.0)},
{'A': (0.5, 0.7, 1.0), 'B': (0.5, 0.7, 1.0)}]
TODO: We should add this as a test case.
There's another improvement I want to make, but that's separate.
this adds three new tests for varLib.build:
1) the input designspace contains a single 'weight' axis with <map>
elements that modify the normalization mapping;
2) the input designspace contains two 'weight' and 'width' axes both
with <map> elements, but the 'width' axis only contains identity
mappings;
3) the input designspace contains two 'weight' and 'width' axes, but
only one axis ('weight') has some <map> elements.
The master interpolatable ttx files for 'TestFamily3' are a subset of
Noto Sans containing only the letters to type the word "FontTools".
Note: the `expect_ttx` test is passing, but the `check_ttx_dump` which ensures the TTX dump is the same after saving and reloading the font, is currently failing, as the "ValueRecordSize" count is None
```
--- /Users/cosimolupo/Documents/Github/fonttools/Tests/varLib/data/test_results/Build.ttx
+++ /var/folders/7k/fl5q53lj51g0d8hxdkrx9_z80000gn/T/tmpoBCAua/tmp1.ttx
@@ -174,8 +174,7 @@
<MVAR>
<Version value="0x00010000"/>
<Reserved value="0"/>
- <ValueRecordSize value="8"/>
- <!-- ValueRecordCount=2 -->
+ <ValueRecordSize value="None"/>
<VarStore Format="1">
<Format value="1"/>
<VarRegionList>
```
Ie. they don't specify any unknown axes, and location is within
axis minimum/maximum. We also allow master / instance locations
to not specify some axes, and we fill in the axis default for those.
We do not accept nonstandard axes if <axes> element is not present.
Breaks one test. Needs updated expectations.
Soon we'll be generating avar as well and all will be better, much better.
b2825ff6b3 (commitcomment-21256990)
Note that the "Tests/varLib/__init__.py" file is necessary so that pytest can distinguish between same-named test modules (e.g. we have another "builder_test.py" file in Tests/feaLib).
