from fontbakery.callable import check
from fontbakery.constants import REGISTERED_AXIS_TAGS
from fontbakery.status import FAIL, PASS, WARN, SKIP
from fontbakery.message import Message
# used to inform get_module_profile whether and how to create a profile
from fontbakery.fonts_profile import profile_factory # noqa:F401 pylint:disable=W0611
profile_imports = ((".", ("shared_conditions",)),)
[docs]@check(
id="com.google.fonts/check/varfont/regular_wght_coord",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'wght' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wght
If a variable font has a 'wght' (Weight) axis, then the coordinate of
its 'Regular' instance is required to be 400.
""",
conditions=["is_variable_font", "has_wght_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/1707",
)
def com_google_fonts_check_varfont_regular_wght_coord(ttFont, regular_wght_coord):
"""The variable font 'wght' (Weight) axis coordinate must be 400 on the
'Regular' instance."""
if regular_wght_coord is None:
yield FAIL, Message("no-regular-instance", '"Regular" instance not present.')
elif regular_wght_coord == 400:
yield PASS, "Regular:wght is 400."
else:
yield FAIL, Message(
"wght-not-400",
f'The "wght" axis coordinate of'
f' the "Regular" instance must be 400.'
f" Got {regular_wght_coord} instead.",
)
[docs]@check(
id="com.google.fonts/check/varfont/regular_wdth_coord",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'wdth' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wdth
If a variable font has a 'wdth' (Width) axis, then the coordinate of
its 'Regular' instance is required to be 100.
""",
conditions=["is_variable_font", "has_wdth_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/1707",
)
def com_google_fonts_check_varfont_regular_wdth_coord(ttFont, regular_wdth_coord):
"""
The variable font 'wdth' (Width) axis coordinate must be 100 on the 'Regular'
instance.
"""
if regular_wdth_coord is None:
yield FAIL, Message("no-regular-instance", '"Regular" instance not present.')
elif regular_wdth_coord == 100:
yield PASS, "Regular:wdth is 100."
else:
yield FAIL, Message(
"wdth-not-100",
f'The "wdth" axis coordinate of'
f' the "Regular" instance must be 100.'
f" Got {regular_wdth_coord} as a default value instead.",
)
[docs]@check(
id="com.google.fonts/check/varfont/regular_slnt_coord",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'slnt' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_slnt
If a variable font has a 'slnt' (Slant) axis, then the coordinate of
its 'Regular' instance is required to be zero.
""",
conditions=["is_variable_font", "has_slnt_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/1707",
)
def com_google_fonts_check_varfont_regular_slnt_coord(ttFont, regular_slnt_coord):
"""
The variable font 'slnt' (Slant) axis coordinate must be zero on the 'Regular'
instance.
"""
if regular_slnt_coord is None:
yield FAIL, Message("no-regular-instance", '"Regular" instance not present.')
elif regular_slnt_coord == 0:
yield PASS, "Regular:slnt is zero."
else:
yield FAIL, Message(
"slnt-not-0",
f'The "slnt" axis coordinate of'
f' the "Regular" instance must be zero.'
f" Got {regular_slnt_coord} as a default value instead.",
)
[docs]@check(
id="com.google.fonts/check/varfont/regular_ital_coord",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'ital' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_ital
If a variable font has a 'ital' (Italic) axis, then the coordinate of
its 'Regular' instance is required to be zero.
""",
conditions=["is_variable_font", "has_ital_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/1707",
)
def com_google_fonts_check_varfont_regular_ital_coord(ttFont, regular_ital_coord):
"""
The variable font 'ital' (Italic) axis coordinate must be zero on the 'Regular'
instance.
"""
if regular_ital_coord is None:
yield FAIL, Message("no-regular-instance", '"Regular" instance not present.')
elif regular_ital_coord == 0:
yield PASS, "Regular:ital is zero."
else:
yield FAIL, Message(
"ital-not-0",
f'The "ital" axis coordinate of'
f' the "Regular" instance must be zero.'
f" Got {regular_ital_coord} as a default value instead.",
)
[docs]@check(
id="com.google.fonts/check/varfont/regular_opsz_coord",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'opsz' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_opsz
If a variable font has an 'opsz' (Optical Size) axis, then
the coordinate of its 'Regular' instance is recommended to be
a value in the range 10 to 16.
""",
conditions=["is_variable_font", "has_opsz_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/1707",
)
def com_google_fonts_check_varfont_regular_opsz_coord(ttFont, regular_opsz_coord):
"""
The variable font 'opsz' (Optical Size) axis coordinate should be between 10 and 16
on the 'Regular' instance.
"""
if regular_opsz_coord is None:
yield FAIL, Message("no-regular-instance", '"Regular" instance not present.')
elif regular_opsz_coord >= 10 and regular_opsz_coord <= 16:
yield PASS, f"Regular:opsz coordinate ({regular_opsz_coord}) looks good."
else:
yield WARN, Message(
"opsz-out-of-range",
f'The "opsz" (Optical Size) coordinate'
f' on the "Regular" instance is recommended'
f" to be a value in the range 10 to 16."
f" Got {regular_opsz_coord} instead.",
)
[docs]@check(
id="com.google.fonts/check/varfont/bold_wght_coord",
rationale="""
The Open-Type spec's registered
design-variation tag 'wght' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wght
does not specify a required value for the 'Bold' instance of a variable font.
But Dave Crossland suggested that we should enforce
a required value of 700 in this case (NOTE: a distinction
is made between "no bold instance present" vs "bold instance is present
but its wght coordinate is not == 700").
""",
conditions=["is_variable_font", "has_wght_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/1707",
)
def com_google_fonts_check_varfont_bold_wght_coord(ttFont, bold_wght_coord):
"""
The variable font 'wght' (Weight) axis coordinate must be 700 on the 'Bold'
instance.
"""
if bold_wght_coord is None:
yield FAIL, Message("no-bold-instance", '"Bold" instance not present.')
elif bold_wght_coord == 700:
yield PASS, "Bold:wght is 700."
else:
yield FAIL, Message(
"wght-not-700",
f'The "wght" axis coordinate of'
f' the "Bold" instance must be 700.'
f" Got {bold_wght_coord} instead.",
)
[docs]@check(
id="com.google.fonts/check/varfont/wght_valid_range",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'wght' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wght
On the 'wght' (Weight) axis, the valid coordinate range is 1-1000.
""",
conditions=["is_variable_font", "has_wght_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/2264",
)
def com_google_fonts_check_varfont_wght_valid_range(ttFont):
"""The variable font 'wght' (Weight) axis coordinate
must be within spec range of 1 to 1000 on all instances."""
passed = True
for instance in ttFont["fvar"].instances:
if "wght" in instance.coordinates:
value = instance.coordinates["wght"]
if value < 1 or value > 1000:
passed = False
yield FAIL, Message(
"wght-out-of-range",
f'Found a bad "wght" coordinate with value {value}'
f" outside of the valid range from 1 to 1000.",
)
break
if passed:
yield PASS, "OK"
[docs]@check(
id="com.google.fonts/check/varfont/wdth_valid_range",
rationale="""
According to the Open-Type spec's
registered design-variation tag 'wdth' available at
https://docs.microsoft.com/en-gb/typography/opentype/spec/dvaraxistag_wdth
On the 'wdth' (Width) axis, the valid numeric range is strictly greater than
zero.
""",
conditions=["is_variable_font", "has_wdth_axis"],
proposal="https://github.com/fonttools/fontbakery/pull/2520",
)
def com_google_fonts_check_varfont_wdth_valid_range(ttFont):
"""The variable font 'wdth' (Width) axis coordinate
must strictly greater than zero."""
passed = True
for instance in ttFont["fvar"].instances:
if "wdth" in instance.coordinates:
value = instance.coordinates["wdth"]
if value < 1:
passed = False
yield FAIL, Message(
"wdth-out-of-range",
f'Found a bad "wdth" coordinate with value {value}'
f" outside of the valid range (> 0).",
)
break
if value > 1000:
yield WARN, Message(
"wdth-greater-than-1000",
f'Found a "wdth" coordinate with value {value}'
f" which is valid but unusual.",
)
break
if passed:
yield PASS, "OK"
[docs]@check(
id="com.google.fonts/check/varfont/slnt_range",
rationale="""
The OpenType spec says at
https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxistag_slnt that:
[...] the scale for the Slant axis is interpreted as the angle of slant
in counter-clockwise degrees from upright. This means that a typical,
right-leaning oblique design will have a negative slant value. This matches
the scale used for the italicAngle field in the post table.
""",
conditions=["is_variable_font", "has_slnt_axis"],
proposal="https://github.com/fonttools/fontbakery/issues/2572",
)
def com_google_fonts_check_varfont_slnt_range(ttFont, slnt_axis):
"""The variable font 'slnt' (Slant) axis coordinate
specifies positive values in its range?"""
if slnt_axis.minValue < 0 and slnt_axis.maxValue >= 0:
yield PASS, "Looks good!"
else:
yield WARN, Message(
"unusual-slnt-range",
f'The range of values for the "slnt" axis in'
f" this font only allows positive coordinates"
f" (from {slnt_axis.minValue} to {slnt_axis.maxValue}),"
f" indicating that this may be a back slanted design,"
f" which is rare. If that's not the case, then"
f' the "slant" axis should be a range of'
f" negative values instead.",
)
[docs]@check(
id="com.typenetwork/check/varfont/ital_range",
rationale="""
The OpenType spec says at
https://learn.microsoft.com/en-us/typography/opentype/spec/dvaraxistag_ital
that:
[...] Valid numeric range: Values must be in the range 0 to 1.
""",
conditions=["is_variable_font", "has_ital_axis"],
experimental="Since 2024/Jan/12",
)
def com_typenetwork_check_varfont_ital_range(ttFont, ital_axis):
"""The variable font 'ital' (Italic) axis coordinates
is in a valid range?"""
if ital_axis.minValue == 0 and ital_axis.maxValue == 1:
yield PASS, "Looks good!"
else:
yield FAIL, Message(
"invalid-ital-range",
f'The range of values for the "ital" axis in'
f" this font is {ital_axis.minValue} to {ital_axis.maxValue}."
f" Italic axis range must be 0 to 1, "
f" where Roman is 0 and Italic 1."
f" If you prefer a bigger variation range consider using"
f' "Slant" axis instead of "Italic".',
)
[docs]@check(
id="com.adobe.fonts/check/varfont/valid_axis_nameid",
rationale="""
According to the 'fvar' documentation in OpenType spec v1.9
https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
The axisNameID field provides a name ID that can be used to obtain strings
from the 'name' table that can be used to refer to the axis in application
user interfaces. The name ID must be greater than 255 and less than 32768.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/3702",
)
def com_adobe_fonts_check_varfont_valid_axis_nameid(ttFont, has_name_table):
"""Validates that the value of axisNameID used by each VariationAxisRecord
is greater than 255 and less than 32768."""
if not has_name_table:
yield FAIL, Message("lacks-table", "Font lacks 'name' table.")
return
passed = True
name_table = ttFont["name"]
font_axis_nameids = [axis.axisNameID for axis in ttFont["fvar"].axes]
invalid_axis_nameids = [val for val in font_axis_nameids if not (255 < val < 32768)]
for nameid in invalid_axis_nameids:
inst_name = name_table.getDebugName(nameid) or "Unnamed"
yield FAIL, Message(
f"invalid-axis-nameid:{nameid}",
f"{inst_name!r} instance has an axisNameID value that"
" is not greater than 255 and less than 32768.",
)
passed = False
if passed:
yield PASS, "All axisNameID values are valid."
[docs]@check(
id="com.adobe.fonts/check/varfont/valid_subfamily_nameid",
rationale="""
According to the 'fvar' documentation in OpenType spec v1.9
https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
The subfamilyNameID field provides a name ID that can be used to obtain
strings from the 'name' table that can be treated as equivalent to name
ID 17 (typographic subfamily) strings for the given instance. Values of
2 or 17 can be used; otherwise, values must be greater than 255 and less
than 32768.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/3703",
)
def com_adobe_fonts_check_varfont_valid_subfamily_nameid(ttFont, has_name_table):
"""Validates that the value of subfamilyNameID used by each InstanceRecord
is 2, 17, or greater than 255 and less than 32768."""
if not has_name_table:
yield FAIL, Message("lacks-table", "Font lacks 'name' table.")
return
passed = True
name_table = ttFont["name"]
font_subfam_nameids = [inst.subfamilyNameID for inst in ttFont["fvar"].instances]
invalid_subfam_nameids = [
val
for val in font_subfam_nameids
if not (255 < val < 32768) and val not in {2, 17}
]
for nameid in invalid_subfam_nameids:
inst_name = name_table.getDebugName(nameid) or "Unnamed"
yield FAIL, Message(
f"invalid-subfamily-nameid:{nameid}",
f"{inst_name!r} instance has a subfamilyNameID value that"
" is neither 2, 17, or greater than 255 and less than 32768.",
)
passed = False
if passed:
yield PASS, "All subfamilyNameID values are valid."
[docs]@check(
id="com.adobe.fonts/check/varfont/valid_postscript_nameid",
rationale="""
According to the 'fvar' documentation in OpenType spec v1.9
https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
The postScriptNameID field provides a name ID that can be used to obtain
strings from the 'name' table that can be treated as equivalent to name
ID 6 (PostScript name) strings for the given instance. Values of 6 and
0xFFFF can be used; otherwise, values must be greater than 255 and less
than 32768.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/3704",
)
def com_adobe_fonts_check_varfont_valid_postscript_nameid(ttFont, has_name_table):
"""Validates that the value of postScriptNameID used by each InstanceRecord
is 6, 0xFFFF, or greater than 255 and less than 32768."""
if not has_name_table:
yield FAIL, Message("lacks-table", "Font lacks 'name' table.")
return
passed = True
name_table = ttFont["name"]
font_postscript_nameids = [
inst.postscriptNameID for inst in ttFont["fvar"].instances
]
invalid_postscript_nameids = [
val
for val in font_postscript_nameids
if not (255 < val < 32768) and val not in {6, 0xFFFF}
]
for nameid in invalid_postscript_nameids:
inst_name = name_table.getDebugName(nameid) or "Unnamed"
yield FAIL, Message(
f"invalid-postscript-nameid:{nameid}",
f"{inst_name!r} instance has a postScriptNameID value that"
" is neither 6, 0xFFFF, or greater than 255 and less than 32768.",
)
passed = False
if passed:
yield PASS, "All postScriptNameID values are valid."
[docs]@check(
id="com.adobe.fonts/check/varfont/valid_default_instance_nameids",
rationale="""
According to the 'fvar' documentation in OpenType spec v1.9.1
https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
The default instance of a font is that instance for which the coordinate
value of each axis is the defaultValue specified in the corresponding
variation axis record. An instance record is not required for the default
instance, though an instance record can be provided. When enumerating named
instances, the default instance should be enumerated even if there is no
corresponding instance record. If an instance record is included for the
default instance (that is, an instance record has coordinates set to default
values), then the nameID value should be set to either 2 or 17 or to a
name ID with the same value as name ID 2 or 17. Also, if a postScriptNameID is
included in instance records, and the postScriptNameID value should be set
to 6 or to a name ID with the same value as name ID 6.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/3708",
)
def com_adobe_fonts_check_varfont_valid_default_instance_nameids(
ttFont, has_name_table
):
"""Validates that when an instance record is included for the default instance,
its subfamilyNameID value is set to a name ID whose string is equal to the
string of either name ID 2 or 17, and its postScriptNameID value is set to a
name ID whose string is equal to the string of name ID 6."""
if not has_name_table:
yield FAIL, Message("lacks-table", "Font lacks 'name' table.")
return
passed = True
name_table = ttFont["name"]
fvar_table = ttFont["fvar"]
font_includes_ps_nameid = any(
inst.postscriptNameID != 0xFFFF for inst in fvar_table.instances
)
axes_dflt_coords = {axis.axisTag: axis.defaultValue for axis in fvar_table.axes}
name2 = name_table.getDebugName(2)
name6 = name_table.getDebugName(6)
name17 = name_table.getDebugName(17)
font_subfam_name = name17 or name2
for i, inst in enumerate(fvar_table.instances, 1):
inst_coords = dict(inst.coordinates.items())
# The instance record has the same coordinates as the default instance
if inst_coords == axes_dflt_coords:
subfam_nameid = inst.subfamilyNameID
subfam_name = name_table.getDebugName(subfam_nameid) or f"Instance #{i}"
postscript_nameid = inst.postscriptNameID
postscript_name = name_table.getDebugName(postscript_nameid) or "None"
# Special handle the 0xFFFF case, to avoid displaying the value as 65535
if postscript_nameid == 0xFFFF:
postscript_nameid = "0xFFFF"
if subfam_name != font_subfam_name:
yield FAIL, Message(
"invalid-default-instance-subfamily-name",
f"{subfam_name!r} instance has the same coordinates as the default"
f" instance; its subfamily name should be {font_subfam_name!r}",
)
passed = False
# Validate the postScriptNameID string only if
# at least one instance record includes it
if font_includes_ps_nameid and postscript_name != name6:
yield FAIL, Message(
"invalid-default-instance-postscript-name",
f"{subfam_name!r} instance has the same coordinates as the default"
f" instance; its postscript name should be {name6!r}, instead of"
f" {postscript_name!r}.",
)
passed = False
if passed:
yield PASS, "All default instance name strings are valid."
[docs]@check(
id="com.adobe.fonts/check/varfont/same_size_instance_records",
rationale="""
According to the 'fvar' documentation in OpenType spec v1.9
https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
All of the instance records in a given font must be the same size, with
all either including or omitting the postScriptNameID field. [...]
If the value is 0xFFFF, then the value is ignored, and no PostScript name
equivalent is provided for the instance.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/3705",
)
def com_adobe_fonts_check_varfont_same_size_instance_records(ttFont):
"""Validates that all of the instance records in a given font have the same size."""
if not ttFont["fvar"].instances:
return SKIP, Message("no-instance-records", "Font has no instance records.")
font_ps_nameids_not_provided = set(
inst.postscriptNameID == 0xFFFF for inst in ttFont["fvar"].instances
)
# 'font_ps_nameids_not_provided' is a set whose values can only be
# {True}, {False}, or {True, False}. So if the size of the set is not 1,
# it means that some instance records have postscriptNameID values while
# others do not.
if len(font_ps_nameids_not_provided) != 1:
return FAIL, Message(
"different-size-instance-records",
"Instance records don't all have the same size.",
)
return PASS, "All instance records have the same size."
[docs]@check(
id="com.adobe.fonts/check/varfont/distinct_instance_records",
rationale="""
According to the 'fvar' documentation in OpenType spec v1.9
https://docs.microsoft.com/en-us/typography/opentype/spec/fvar
All of the instance records in a font should have distinct coordinates
and distinct subfamilyNameID and postScriptName ID values. If two or more
records share the same coordinates, the same nameID values or the same
postScriptNameID values, then all but the first can be ignored.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/3706",
)
def com_adobe_fonts_check_varfont_distinct_instance_records(ttFont, has_name_table):
"""Validates that all of the instance records in a given font have distinct data."""
if not has_name_table:
yield FAIL, Message("lacks-table", "Font lacks 'name' table.")
return
passed = True
name_table = ttFont["name"]
unique_inst_recs = set()
for i, inst in enumerate(ttFont["fvar"].instances, 1):
inst_coords = list(inst.coordinates.items())
inst_subfam_nameid = inst.subfamilyNameID
inst_postscript_nameid = inst.postscriptNameID
inst_data = (tuple(inst_coords), inst_subfam_nameid, inst_postscript_nameid)
if inst_data not in unique_inst_recs:
unique_inst_recs.add(inst_data)
else: # non-unique instance was found
inst_name = name_table.getDebugName(inst_subfam_nameid)
if inst_name is None:
inst_name = f"Instance #{i}"
yield WARN, Message(
f"repeated-instance-record:{inst_name}",
f"{inst_name!r} is a repeated instance record.",
)
passed = False
if passed:
yield PASS, "All instance records are distinct."
[docs]@check(
id="com.adobe.fonts/check/varfont/foundry_defined_tag_name",
rationale="""
According to the Open-Type spec's syntactic requirements for
foundry-defined design-variation axis tags available at
https://learn.microsoft.com/en-us/typography/opentype/spec/dvaraxisreg
Foundry-defined tags must begin with an uppercase letter
and must use only uppercase letters or digits.
""",
conditions=["is_variable_font"],
proposal="https://github.com/fonttools/fontbakery/issues/4043",
)
def com_adobe_fonts_check_varfont_foundry_defined_tag_name(ttFont):
"Validate foundry-defined design-variation axis tag names."
passed = True
for axis in ttFont["fvar"].axes:
axisTag = axis.axisTag
if axisTag in REGISTERED_AXIS_TAGS:
continue
if axisTag.lower() in REGISTERED_AXIS_TAGS:
yield WARN, Message(
"foundry-defined-similar-registered-name",
f'Foundry-defined tag "{axisTag}" is very similar to'
f' registered tag "{axisTag.lower()}", consider renaming.\n'
f"If this tag was meant to be a registered tag, please"
f" use all lowercase letters in the tag name.",
)
firstChar = ord(axisTag[0])
if not (firstChar >= ord("A") and firstChar <= ord("Z")):
passed = False
yield FAIL, Message(
"invalid-foundry-defined-tag-first-letter",
f'Please fix axis tag "{axisTag}".\n'
f"Foundry-defined tags must begin with an uppercase letter.",
)
for i in range(3):
char = ord(axisTag[1 + i])
if not (
(char >= ord("0") and char <= ord("9"))
or (char >= ord("A") and char <= ord("Z"))
):
passed = False
yield FAIL, Message(
"invalid-foundry-defined-tag-chars",
f'Please fix axis tag "{axisTag}".\n'
f"Foundry-defined tags must only use"
f" uppercase or digits.",
)
if passed:
yield PASS, f"Axis tag '{axisTag}' looks good."