def diff_attribs(font_before, font_after, scale_upm=True):
"""Find attribute differences between two fonts.
Rows are matched by using attrib.
Parameters
----------
font_before: DFont
font_after: DFont
scale_upms:
Scale values in relation to the font's upms. See readme
for example.
Returns
-------
dict
{
"modified": [diff_table]
}
"""
attribs_before = font_before.attribs
attribs_after = font_after.attribs
upm_before = font_before.ttfont['head'].unitsPerEm
upm_after = font_after.ttfont['head'].unitsPerEm
attribs_before_h = {i['attrib']: i for i in attribs_before}
attribs_after_h = {i['attrib']: i for i in attribs_after}
modified = _modified_attribs(attribs_before_h, attribs_after_h,
upm_before, upm_after, scale_upm=scale_upm)
modified = DiffTable("attribs modified", font_before, font_after, data=modified)
modified.report_columns(["table", "attrib", "value_a", "value_b"])
modified.sort(key=lambda k: k["table"])
return {'modified': modified}
def diff_cbdt_glyphs(font_before,
font_after,
thresh=4,
render_path=None,
html_output=False):
cbdt_before = read_cbdt(font_before.ttfont)
cbdt_after = read_cbdt(font_after.ttfont)
chars_before = {r["string"]: str(r["glyph"]) for r in font_before.glyphs}
chars_after = {r["string"]: str(r["glyph"]) for r in font_after.glyphs}
modified = []
for char in set(chars_before) & set(chars_after):
glyph_name_before = chars_before[char]
glyph_name_after = chars_after[char]
if glyph_name_before in cbdt_before and glyph_name_after in cbdt_after:
diff = _diff_images(cbdt_before[glyph_name_before],
cbdt_after[glyph_name_after])
if diff > thresh:
modified.append({
"glyph before":
glyph_name_before,
"glyph after":
glyph_name_after,
"string":
char,
"diff":
diff,
"image":
f"<img src='{render_path}/{glyph_name_before}.gif'>",
})
modified = DiffTable("cbdt glyphs modified",
font_before,
font_after,
data=modified,
renderable=True)
if render_path and html_output:
modified.report_columns(
["glyph before", "glyph after", "diff", "string", "image"])
else:
modified.report_columns(
["glyph before", "glyph after", "diff", "string"])
modified.sort(key=lambda k: abs(k["diff"]), reverse=True)
return {"modified": modified}
def diff_metrics(font_before, font_after, thresh=1, scale_upms=True):
"""Find metrics differences between two fonts.
Rows are matched by each using glyph key, which consists of
the glyph's characters and OT features.
Parameters
----------
font_before: DFont
font_after: DFont
thresh:
Ignore modified metrics under this value
scale_upms:
Scale values in relation to the font's upms. See readme
for example.
Returns
-------
dict
{
"new": [diff_table],
"missing": [diff_table],
"modified": [diff_table]
}
"""
metrics_before = font_before.metrics
metrics_after = font_after.metrics
upm_before = font_before.ttfont['head'].unitsPerEm
upm_after = font_after.ttfont['head'].unitsPerEm
metrics_before_h = {i['glyph'].key: i for i in metrics_before}
metrics_after_h = {i['glyph'].key: i for i in metrics_after}
modified = _modified_metrics(metrics_before_h, metrics_after_h, thresh,
upm_before, upm_after, scale_upms)
modified = DiffTable("metrics modified",
font_before,
font_after,
data=modified,
renderable=True)
modified.report_columns(["glyph", "diff_adv"])
modified.sort(key=lambda k: k["diff_adv"], reverse=True)
return {'modified': modified}
def diff_marks(font_before,
font_after,
marks_before,
marks_after,
name=None,
thresh=4,
scale_upms=True):
"""diff mark positioning.
Marks are flattened first.
Rows are matched by each base glyph's + mark glyph's key
Parameters
----------
font_before: DFont
font_after: DFont
marks_before: diff_table
marks_after: diff_table
thresh: Ignore differences below this value
scale_upms:
Scale values in relation to the font's upms. See readme
for example.
Returns
-------
dict
{
"new": [diff_table],
"missing": [diff_table],
"modified": [diff_table]
}
"""
upm_before = font_before.ttfont['head'].unitsPerEm
upm_after = font_after.ttfont['head'].unitsPerEm
charset_before = set(
[font_before.glyph(g).key for g in font_before.glyphset])
charset_after = set([font_after.glyph(g).key for g in font_after.glyphset])
marks_before_h = {
i['base_glyph'].key + i['mark_glyph'].key: i
for i in marks_before if i['base_glyph'].key in charset_after
and i['mark_glyph'].key in charset_after
}
marks_after_h = {
i['base_glyph'].key + i['mark_glyph'].key: i
for i in marks_after if i['base_glyph'].key in charset_before
and i['mark_glyph'].key in charset_before
}
missing = _subtract_items(marks_before_h, marks_after_h)
new = _subtract_items(marks_after_h, marks_before_h)
modified = _modified_marks(marks_before_h,
marks_after_h,
thresh,
upm_before,
upm_after,
scale_upms=True)
new = DiffTable(name + "_new",
font_before,
font_after,
data=new,
renderable=True)
new.report_columns(
["base_glyph", "base_x", "base_y", "mark_glyph", "mark_x", "mark_y"])
new.sort(key=lambda k: abs(k["base_x"]) - abs(k["mark_x"]) + \
abs(k["base_y"]) - abs(k["mark_y"]))
missing = DiffTable(name + "_missing",
font_before,
font_after,
data=missing,
renderable=True)
missing.report_columns(
["base_glyph", "base_x", "base_y", "mark_glyph", "mark_x", "mark_y"])
missing.sort(key=lambda k: abs(k["base_x"]) - abs(k["mark_x"]) + \
abs(k["base_y"]) - abs(k["mark_y"]))
modified = DiffTable(name + "_modified",
font_before,
font_after,
data=modified,
renderable=True)
modified.report_columns(["base_glyph", "mark_glyph", "diff_x", "diff_y"])
modified.sort(key=lambda k: abs(k["diff_x"]) + abs(k["diff_y"]),
reverse=True)
return {
"new": new,
"missing": missing,
"modified": modified,
}
def diff_kerning(font_before, font_after, thresh=2, scale_upms=True):
"""Find kerning differences between two fonts.
Class kerns are flattened and then tested for differences.
Rows are matched by the left and right glyph keys.
Some fonts use a kern table instead of gpos kerns, test these
if no gpos kerns exist. This problem exists in Open Sans v1.
Parameters
----------
font_before: DFont
font_after: DFont
thresh: Ignore differences below this value
scale_upms:
Scale values in relation to the font's upms. See readme
for example.
Returns
-------
dict
{
"new": [diff_table],
"missing": [diff_table],
"modified": [diff_table]
}
"""
kern_before = font_before.kerns
kern_after = font_after.kerns
upm_before = font_before.ttfont['head'].unitsPerEm
upm_after = font_after.ttfont['head'].unitsPerEm
charset_before = set(
[font_before.glyph(g).key for g in font_before.glyphset])
charset_after = set([font_after.glyph(g).key for g in font_after.glyphset])
kern_before_h = {
i['left'].key + i['right'].key: i
for i in kern_before
if i['left'].key in charset_after and i['right'].key in charset_after
}
kern_after_h = {
i['left'].key + i['right'].key: i
for i in kern_after
if i['left'].key in charset_before and i['right'].key in charset_before
}
missing = _subtract_items(kern_before_h, kern_after_h)
missing = [i for i in missing if abs(i["value"]) >= 1]
new = _subtract_items(kern_after_h, kern_before_h)
new = [i for i in new if abs(i["value"]) >= 1]
modified = _modified_kerns(kern_before_h,
kern_after_h,
thresh,
upm_before,
upm_after,
scale_upms=scale_upms)
missing = DiffTable("kerns missing",
font_before,
font_after,
data=missing,
renderable=True)
missing.report_columns(["left", "right", "value", "string"])
missing.sort(key=lambda k: abs(k["value"]), reverse=True)
new = DiffTable("kerns new",
font_before,
font_after,
data=new,
renderable=True)
new.report_columns(["left", "right", "value", "string"])
new.sort(key=lambda k: abs(k["value"]), reverse=True)
modified = DiffTable("kerns modified",
font_before,
font_after,
data=modified,
renderable=True)
modified.report_columns(["left", "right", "diff", "string"])
modified.sort(key=lambda k: abs(k["diff"]), reverse=True)
return {
'new': new,
'missing': missing,
'modified': modified,
}
def diff_glyphs(font_before,
font_after,
thresh=0.00,
scale_upms=True,
render_diffs=False):
"""Find glyph differences between two fonts.
Rows are matched by glyph key, which consists of
the glyph's characters and OT features.
Parameters
----------
font_before: DFont
font_after: DFont
thresh: Ignore differences below this value
scale_upms:
Scale values in relation to the font's upms. See readme
for example.
render_diffs: Boolean
If True, diff glyphs by rendering them. Return ratio of changed
pixels.
If False, diff glyphs by calculating the surface area of each glyph.
Return ratio of changed surface area.
Returns
-------
dict
{
"new": DiffTable,
"missing": DiffTable,
"modified": DiffTable
}
"""
glyphs_before = font_before.glyphs
glyphs_after = font_after.glyphs
glyphs_before_h = {r['glyph'].key: r for r in glyphs_before}
glyphs_after_h = {r['glyph'].key: r for r in glyphs_after}
missing = _subtract_items(glyphs_before_h, glyphs_after_h)
new = _subtract_items(glyphs_after_h, glyphs_before_h)
modified = _modified_glyphs(glyphs_before_h,
glyphs_after_h,
thresh,
scale_upms=scale_upms,
render_diffs=render_diffs)
new = DiffTable("glyphs new",
font_before,
font_after,
data=new,
renderable=True)
new.report_columns(["glyph", "area", "string"])
new.sort(key=lambda k: k["glyph"].name)
missing = DiffTable("glyphs missing",
font_before,
font_after,
data=missing,
renderable=True)
missing.report_columns(["glyph", "area", "string"])
missing.sort(key=lambda k: k["glyph"].name)
modified = DiffTable("glyphs modified",
font_before,
font_after,
data=modified,
renderable=True)
modified.report_columns(["glyph", "diff", "string"])
modified.sort(key=lambda k: abs(k["diff"]), reverse=True)
return {'new': new, 'missing': missing, 'modified': modified}
def diff_nametable(font_before, font_after):
"""Find nametable differences between two fonts.
Rows are matched by attribute id.
Parameters
----------
font_before: DFont
font_after: DFont
Returns
-------
DiffTable
"""
nametable_before = font_before.names
nametable_after = font_after.names
names_before_h = {i['id']: i for i in nametable_before}
names_after_h = {i['id']: i for i in nametable_after}
missing = _subtract_items(names_before_h, names_after_h)
new = _subtract_items(names_after_h, names_before_h)
modified = _modified_names(names_before_h, names_after_h)
new = DiffTable("names new", font_before, font_after, data=new)
new.report_columns(["id", "string"])
new.sort(key=lambda k: k["id"])
missing = DiffTable("names missing", font_before, font_after, data=missing)
missing.report_columns(["id", "string"])
missing.sort(key=lambda k: k["id"])
modified = DiffTable("names modified",
font_before,
font_after,
data=modified)
modified.report_columns(["id", "string_a", "string_b"])
modified.sort(key=lambda k: k["id"])
return {
'new': new,
'missing': missing,
'modified': modified,
}
def _gdef(font_before, font_after, type_):
base_before = getattr(font_before, type_)
base_after = getattr(font_after, type_)
base_before_h = {i['glyph'].key: i for i in base_before}
base_after_h = {i['glyph'].key: i for i in base_after}
missing = _subtract_items(base_before_h, base_after_h)
new = _subtract_items(base_after_h, base_before_h)
new = DiffTable(f"{type_} new",
font_before,
font_after,
data=new,
renderable=True)
new.report_columns(["glyph"])
new.sort(key=lambda k: k["glyph"].width, reverse=True)
missing = DiffTable(f"{type_} missing",
font_before,
font_after,
data=missing,
renderable=True)
missing.report_columns(["glyph"])
missing.sort(key=lambda k: k["glyph"].width, reverse=True)
return {
"new": new,
"missing": missing,
}
