+
Skip to content

Fix and improve EBDT #3619

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 5 commits into
base: main
Choose a base branch
from
Open

Fix and improve EBDT #3619

Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
0c12122
fix minor dict bug, rename to match spec
NightFurySL2001 Aug 28, 2024
c85f118
store strikeIndex of BitmapGlyph
NightFurySL2001 Aug 28, 2024
89a3779
add common functionalities to match MetricsMixin
NightFurySL2001 Aug 28, 2024
239aab3
bit mask fix
NightFurySL2001 Aug 28, 2024
105e50a
check for out of bounds condition and add docs
NightFurySL2001 Aug 29, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
91 changes: 74 additions & 17 deletions Lib/fontTools/ttLib/tables/E_B_D_T_.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,9 +31,9 @@

ebdtComponentFormat = """
> # big endian
glyphCode: H
xOffset: b
yOffset: b
glyphID: H
xOffset: b
yOffset: b
"""


Expand Down Expand Up @@ -63,7 +63,7 @@ def decompile(self, data, ttFont):
# The actual bitmap data is stored in the EBDT.
locator = ttFont[self.__class__.locatorName]
self.strikeData = []
for curStrike in locator.strikes:
for strikeIndex, curStrike in enumerate(locator.strikes):
bitmapGlyphDict = {}
self.strikeData.append(bitmapGlyphDict)
for indexSubTable in curStrike.indexSubTables:
Expand All @@ -78,7 +78,7 @@ def decompile(self, data, ttFont):
imageFormatClass = self.getImageFormatClass(
indexSubTable.imageFormat
)
curGlyph = imageFormatClass(curGlyphData, ttFont)
curGlyph = imageFormatClass(curGlyphData, ttFont, strikeIndex)
glyphDict[curLoc] = curGlyph
bitmapGlyphDict[curName] = curGlyph

Expand Down Expand Up @@ -178,7 +178,7 @@ def fromXML(self, name, attrs, content, ttFont):
imageFormat = safeEval(name[len(_bitmapGlyphSubclassPrefix) :])
glyphName = attrs["name"]
imageFormatClass = self.getImageFormatClass(imageFormat)
curGlyph = imageFormatClass(None, None)
curGlyph = imageFormatClass(None, None, strikeIndex)
curGlyph.fromXML(name, attrs, content, ttFont)
assert glyphName not in bitmapGlyphDict, (
"Duplicate glyphs with the same name '%s' in the same strike."
Expand All @@ -200,22 +200,26 @@ def fromXML(self, name, attrs, content, ttFont):

class EbdtComponent(object):
def toXML(self, writer, ttFont):
writer.begintag("ebdtComponent", [("name", self.name)])
writer.begintag("EbdtComponent", [("name", self.name)])
writer.newline()
for componentName in sstruct.getformat(ebdtComponentFormat)[1][1:]:
for componentName in sstruct.getformat(ebdtComponentFormat)[1]:
if componentName == "glyphID":
continue
writer.simpletag(componentName, value=getattr(self, componentName))
writer.newline()
writer.endtag("ebdtComponent")
writer.endtag("EbdtComponent")
writer.newline()

def fromXML(self, name, attrs, content, ttFont):
self.name = attrs["name"]
componentNames = set(sstruct.getformat(ebdtComponentFormat)[1][1:])
componentNames = set(sstruct.getformat(ebdtComponentFormat)[1])
for element in content:
if not isinstance(element, tuple):
continue
name, attrs, content = element
if name in componentNames:
if name == "glyphID":
log.warning("provided glyphID is not used when parsing '%s'", name)
elif name in componentNames:
vars(self)[name] = safeEval(attrs["value"])
else:
log.warning("unknown name '%s' being ignored by EbdtComponent.", name)
Expand Down Expand Up @@ -439,9 +443,11 @@ class BitmapGlyph(object):
"extfile": (_writeExtFileImageData, _readExtFileImageData),
}

def __init__(self, data, ttFont):
def __init__(self, data, ttFont, strikeIndex):
self.data = data
self.ttFont = ttFont
# keep track which strike this glyph belong to, used for format 8/9 component finding
self.strikeIndex = strikeIndex
# TODO Currently non-lazy decompilation is untested here...
# if not ttFont.lazy:
# self.decompile()
Expand Down Expand Up @@ -757,13 +763,64 @@ def fromXML(self, name, attrs, content, ttFont):
if not isinstance(compElement, tuple):
continue
name, attrs, content = compElement
if name == "ebdtComponent":
if name == "EbdtComponent":
curComponent = EbdtComponent()
curComponent.fromXML(name, attrs, content, ttFont)
self.componentArray.append(curComponent)
else:
log.warning("'%s' being ignored in component array.", name)

def getRow(self, row: int, bitDepth=1, metrics=None, reverseBytes=False):
"""Returns the bits in a row of the bitmap glyph as bytes. The bits are merged from all components in the glyph.
Components that contains bits offsetted out of bounds will be cropped to match metrics.
Overlapped bits between components will be merged by ORing them.
This function dynamically calculates the bitmap from the components in the glyph. It should not be viewed as raw bitmap data from the font file.

Params:
* row: the row index of the bitmap glyph to get, starting from 0 at the top.
"""
if metrics is None:
metrics = self.metrics
assert 0 <= row and row < metrics.height, "Illegal row access in bitmap"

numBytesInRow = (bitDepth * metrics.width + 7) // 8
rowData = int.from_bytes(bytes([0] * numBytesInRow))
for component in self.componentArray:
if row + component.yOffset < 0 or row + component.yOffset >= metrics.height:
# skip out of bound component rows
continue

componentGlyph = self.ttFont["EBDT"].strikeData[self.strikeIndex][component.name]
# get the row after shifting xOffset
componentRow = componentGlyph.getRow(row + component.xOffset, bitDepth, metrics, reverseBytes)
# pad row until it is the same length as the rowData
componentRow = componentRow + bytes([0] * (numBytesInRow - len(componentRow) ))
# shift row horizontally
if component.yOffset >= 0:
componentRowInt = int.from_bytes(componentRow) >> (component.yOffset * bitDepth)
else:
componentRowInt = int.from_bytes(componentRow) << (-component.yOffset * bitDepth)

# assume that the merging of two bits is done by ORing them
rowData = rowData | componentRowInt

# mask out the bits that are out of bound
rowBitMask = ((1 << (bitDepth * metrics.width)) - 1) << (8 * numBytesInRow - bitDepth * metrics.width)
rowData = rowData & rowBitMask

return rowData.to_bytes(numBytesInRow, 'big')

def setRows(self, *args, **kwargs):
raise NotImplementedError("setRows() is unavailable for component bitmap glyphs, use addComponent() instead")

def addComponent(self, glyphName, xOffset=0, yOffset=0):
component = EbdtComponent()
assert glyphName in self.ttFont["EBDT"].strikeData[self.strikeIndex], "Glyph '%s' not in font strike." % glyphName
component.name = glyphName
component.xOffset = xOffset
component.yOffset = yOffset
self.componentArray.append(component)


class ebdt_bitmap_format_8(BitmapPlusSmallMetricsMixin, ComponentBitmapGlyph):
def decompile(self):
Expand All @@ -777,7 +834,7 @@ def decompile(self):
for i in range(numComponents):
curComponent = EbdtComponent()
dummy, data = sstruct.unpack2(ebdtComponentFormat, data, curComponent)
curComponent.name = self.ttFont.getGlyphName(curComponent.glyphCode)
curComponent.name = self.ttFont.getGlyphName(curComponent.glyphID)
self.componentArray.append(curComponent)

def compile(self, ttFont):
Expand All @@ -786,7 +843,7 @@ def compile(self, ttFont):
dataList.append(b"\0")
dataList.append(struct.pack(">H", len(self.componentArray)))
for curComponent in self.componentArray:
curComponent.glyphCode = ttFont.getGlyphID(curComponent.name)
curComponent.glyphID = ttFont.getGlyphID(curComponent.name)
dataList.append(sstruct.pack(ebdtComponentFormat, curComponent))
return bytesjoin(dataList)

Expand All @@ -801,15 +858,15 @@ def decompile(self):
for i in range(numComponents):
curComponent = EbdtComponent()
dummy, data = sstruct.unpack2(ebdtComponentFormat, data, curComponent)
curComponent.name = self.ttFont.getGlyphName(curComponent.glyphCode)
curComponent.name = self.ttFont.getGlyphName(curComponent.glyphID)
self.componentArray.append(curComponent)

def compile(self, ttFont):
dataList = []
dataList.append(sstruct.pack(bigGlyphMetricsFormat, self.metrics))
dataList.append(struct.pack(">H", len(self.componentArray)))
for curComponent in self.componentArray:
curComponent.glyphCode = ttFont.getGlyphID(curComponent.name)
curComponent.glyphID = ttFont.getGlyphID(curComponent.name)
dataList.append(sstruct.pack(ebdtComponentFormat, curComponent))
return bytesjoin(dataList)

Expand Down
点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载