blob: 2577fa7658cb20aa503b429261aed62880651ab1 [file] [log] [blame]
colorLib.builder: Build COLR/CPAL tables from scratch
import collections
import copy
import enum
from functools import partial
from math import ceil, log
from typing import (
from fontTools.misc.arrayTools import intRect
from fontTools.misc.fixedTools import fixedToFloat
from fontTools.ttLib.tables import C_O_L_R_
from fontTools.ttLib.tables import C_P_A_L_
from fontTools.ttLib.tables import _n_a_m_e
from fontTools.ttLib.tables import otTables as ot
from fontTools.ttLib.tables.otTables import ExtendMode, CompositeMode
from .errors import ColorLibError
from .geometry import round_start_circle_stable_containment
from .table_builder import BuildCallback, TableBuilder
# TODO move type aliases to colorLib.types?
T = TypeVar("T")
_Kwargs = Mapping[str, Any]
_PaintInput = Union[int, _Kwargs, ot.Paint, Tuple[str, "_PaintInput"]]
_PaintInputList = Sequence[_PaintInput]
_ColorGlyphsDict = Dict[str, Union[_PaintInputList, _PaintInput]]
_ColorGlyphsV0Dict = Dict[str, Sequence[Tuple[str, int]]]
_ClipBoxInput = Union[
Tuple[int, int, int, int, int], # format 1, variable
Tuple[int, int, int, int], # format 0, non-variable
def _beforeBuildPaintRadialGradient(paint, source):
x0 = source["x0"]
y0 = source["y0"]
r0 = source["r0"]
x1 = source["x1"]
y1 = source["y1"]
r1 = source["r1"]
# TODO apparently no builder_test confirms this works (?)
# avoid abrupt change after rounding when c0 is near c1's perimeter
c = round_start_circle_stable_containment((x0, y0), r0, (x1, y1), r1)
x0, y0 = c.centre
r0 = c.radius
# update source to ensure paint is built with corrected values
source["x0"] = x0
source["y0"] = y0
source["r0"] = r0
source["x1"] = x1
source["y1"] = y1
source["r1"] = r1
return paint, source
def _defaultColorStop():
colorStop = ot.ColorStop()
colorStop.Alpha = _DEFAULT_ALPHA
return colorStop
def _defaultVarColorStop():
colorStop = ot.VarColorStop()
colorStop.Alpha = _DEFAULT_ALPHA
return colorStop
def _defaultColorLine():
colorLine = ot.ColorLine()
colorLine.Extend = ExtendMode.PAD
return colorLine
def _defaultVarColorLine():
colorLine = ot.VarColorLine()
colorLine.Extend = ExtendMode.PAD
return colorLine
def _defaultPaintSolid():
paint = ot.Paint()
paint.Alpha = _DEFAULT_ALPHA
return paint
def _buildPaintCallbacks():
return {
): _beforeBuildPaintRadialGradient,
): _beforeBuildPaintRadialGradient,
(BuildCallback.CREATE_DEFAULT, ot.ColorStop): _defaultColorStop,
(BuildCallback.CREATE_DEFAULT, ot.VarColorStop): _defaultVarColorStop,
(BuildCallback.CREATE_DEFAULT, ot.ColorLine): _defaultColorLine,
(BuildCallback.CREATE_DEFAULT, ot.VarColorLine): _defaultVarColorLine,
): _defaultPaintSolid,
): _defaultPaintSolid,
def populateCOLRv0(
table: ot.COLR,
colorGlyphsV0: _ColorGlyphsV0Dict,
glyphMap: Optional[Mapping[str, int]] = None,
"""Build v0 color layers and add to existing COLR table.
table: a raw ``otTables.COLR()`` object (not ttLib's ``table_C_O_L_R_``).
colorGlyphsV0: map of base glyph names to lists of (layer glyph names,
color palette index) tuples. Can be empty.
glyphMap: a map from glyph names to glyph indices, as returned from
``TTFont.getReverseGlyphMap()``, to optionally sort base records by GID.
if glyphMap is not None:
colorGlyphItems = sorted(
colorGlyphsV0.items(), key=lambda item: glyphMap[item[0]]
colorGlyphItems = colorGlyphsV0.items()
baseGlyphRecords = []
layerRecords = []
for baseGlyph, layers in colorGlyphItems:
baseRec = ot.BaseGlyphRecord()
baseRec.BaseGlyph = baseGlyph
baseRec.FirstLayerIndex = len(layerRecords)
baseRec.NumLayers = len(layers)
for layerGlyph, paletteIndex in layers:
layerRec = ot.LayerRecord()
layerRec.LayerGlyph = layerGlyph
layerRec.PaletteIndex = paletteIndex
table.BaseGlyphRecordArray = table.LayerRecordArray = None
if baseGlyphRecords:
table.BaseGlyphRecordArray = ot.BaseGlyphRecordArray()
table.BaseGlyphRecordArray.BaseGlyphRecord = baseGlyphRecords
if layerRecords:
table.LayerRecordArray = ot.LayerRecordArray()
table.LayerRecordArray.LayerRecord = layerRecords
table.BaseGlyphRecordCount = len(baseGlyphRecords)
table.LayerRecordCount = len(layerRecords)
def buildCOLR(
colorGlyphs: _ColorGlyphsDict,
version: Optional[int] = None,
glyphMap: Optional[Mapping[str, int]] = None,
varStore: Optional[ot.VarStore] = None,
varIndexMap: Optional[ot.DeltaSetIndexMap] = None,
clipBoxes: Optional[Dict[str, _ClipBoxInput]] = None,
) -> C_O_L_R_.table_C_O_L_R_:
"""Build COLR table from color layers mapping.
colorGlyphs: map of base glyph name to, either list of (layer glyph name,
color palette index) tuples for COLRv0; or a single ``Paint`` (dict) or
list of ``Paint`` for COLRv1.
version: the version of COLR table. If None, the version is determined
by the presence of COLRv1 paints or variation data (varStore), which
require version 1; otherwise, if all base glyphs use only simple color
layers, version 0 is used.
glyphMap: a map from glyph names to glyph indices, as returned from
TTFont.getReverseGlyphMap(), to optionally sort base records by GID.
varStore: Optional ItemVarationStore for deltas associated with v1 layer.
varIndexMap: Optional DeltaSetIndexMap for deltas associated with v1 layer.
clipBoxes: Optional map of base glyph name to clip box 4- or 5-tuples:
(xMin, yMin, xMax, yMax) or (xMin, yMin, xMax, yMax, varIndexBase).
A new COLR table.
self = C_O_L_R_.table_C_O_L_R_()
if varStore is not None and version == 0:
raise ValueError("Can't add VarStore to COLRv0")
if version in (None, 0) and not varStore:
# split color glyphs into v0 and v1 and encode separately
colorGlyphsV0, colorGlyphsV1 = _split_color_glyphs_by_version(colorGlyphs)
if version == 0 and colorGlyphsV1:
raise ValueError("Can't encode COLRv1 glyphs in COLRv0")
# unless explicitly requested for v1 or have variations, in which case
# we encode all color glyph as v1
colorGlyphsV0, colorGlyphsV1 = {}, colorGlyphs
colr = ot.COLR()
populateCOLRv0(colr, colorGlyphsV0, glyphMap)
colr.LayerList, colr.BaseGlyphList = buildColrV1(colorGlyphsV1, glyphMap)
if version is None:
version = 1 if (varStore or colorGlyphsV1) else 0
elif version not in (0, 1):
raise NotImplementedError(version)
self.version = colr.Version = version
if version == 0:
self.ColorLayers = self._decompileColorLayersV0(colr)
clipBoxes = {
name: clipBoxes[name] for name in clipBoxes or {} if name in colorGlyphsV1
colr.ClipList = buildClipList(clipBoxes) if clipBoxes else None
colr.VarIndexMap = varIndexMap
colr.VarStore = varStore
self.table = colr
return self
def buildClipList(clipBoxes: Dict[str, _ClipBoxInput]) -> ot.ClipList:
clipList = ot.ClipList()
clipList.Format = 1
clipList.clips = {name: buildClipBox(box) for name, box in clipBoxes.items()}
return clipList
def buildClipBox(clipBox: _ClipBoxInput) -> ot.ClipBox:
if isinstance(clipBox, ot.ClipBox):
return clipBox
n = len(clipBox)
clip = ot.ClipBox()
if n not in (4, 5):
raise ValueError(f"Invalid ClipBox: expected 4 or 5 values, found {n}")
clip.xMin, clip.yMin, clip.xMax, clip.yMax = intRect(clipBox[:4])
clip.Format = int(n == 5) + 1
if n == 5:
clip.VarIndexBase = int(clipBox[4])
return clip
class ColorPaletteType(enum.IntFlag):
def _missing_(cls, value):
# enforce reserved bits
if isinstance(value, int) and (value < 0 or value & 0xFFFC != 0):
raise ValueError(f"{value} is not a valid {cls.__name__}")
return super()._missing_(value)
# None, 'abc' or {'en': 'abc', 'de': 'xyz'}
_OptionalLocalizedString = Union[None, str, Dict[str, str]]
def buildPaletteLabels(
labels: Iterable[_OptionalLocalizedString], nameTable: _n_a_m_e.table__n_a_m_e
) -> List[Optional[int]]:
return [
nameTable.addMultilingualName(l, mac=False)
if isinstance(l, dict)
else C_P_A_L_.table_C_P_A_L_.NO_NAME_ID
if l is None
else nameTable.addMultilingualName({"en": l}, mac=False)
for l in labels
def buildCPAL(
palettes: Sequence[Sequence[Tuple[float, float, float, float]]],
paletteTypes: Optional[Sequence[ColorPaletteType]] = None,
paletteLabels: Optional[Sequence[_OptionalLocalizedString]] = None,
paletteEntryLabels: Optional[Sequence[_OptionalLocalizedString]] = None,
nameTable: Optional[_n_a_m_e.table__n_a_m_e] = None,
) -> C_P_A_L_.table_C_P_A_L_:
"""Build CPAL table from list of color palettes.
palettes: list of lists of colors encoded as tuples of (R, G, B, A) floats
in the range [0..1].
paletteTypes: optional list of ColorPaletteType, one for each palette.
paletteLabels: optional list of palette labels. Each lable can be either:
None (no label), a string (for for default English labels), or a
localized string (as a dict keyed with BCP47 language codes).
paletteEntryLabels: optional list of palette entry labels, one for each
palette entry (see paletteLabels).
nameTable: optional name table where to store palette and palette entry
labels. Required if either paletteLabels or paletteEntryLabels is set.
A new CPAL v0 or v1 table, if custom palette types or labels are specified.
if len({len(p) for p in palettes}) != 1:
raise ColorLibError("color palettes have different lengths")
if (paletteLabels or paletteEntryLabels) and not nameTable:
raise TypeError(
"nameTable is required if palette or palette entries have labels"
cpal = C_P_A_L_.table_C_P_A_L_()
cpal.numPaletteEntries = len(palettes[0])
cpal.palettes = []
for i, palette in enumerate(palettes):
colors = []
for j, color in enumerate(palette):
if not isinstance(color, tuple) or len(color) != 4:
raise ColorLibError(
f"In palette[{i}][{j}]: expected (R, G, B, A) tuple, got {color!r}"
if any(v > 1 or v < 0 for v in color):
raise ColorLibError(
f"palette[{i}][{j}] has invalid out-of-range [0..1] color: {color!r}"
# input colors are RGBA, CPAL encodes them as BGRA
red, green, blue, alpha = color
C_P_A_L_.Color(*(round(v * 255) for v in (blue, green, red, alpha)))
if any(v is not None for v in (paletteTypes, paletteLabels, paletteEntryLabels)):
cpal.version = 1
if paletteTypes is not None:
if len(paletteTypes) != len(palettes):
raise ColorLibError(
f"Expected {len(palettes)} paletteTypes, got {len(paletteTypes)}"
cpal.paletteTypes = [ColorPaletteType(t).value for t in paletteTypes]
cpal.paletteTypes = [C_P_A_L_.table_C_P_A_L_.DEFAULT_PALETTE_TYPE] * len(
if paletteLabels is not None:
if len(paletteLabels) != len(palettes):
raise ColorLibError(
f"Expected {len(palettes)} paletteLabels, got {len(paletteLabels)}"
cpal.paletteLabels = buildPaletteLabels(paletteLabels, nameTable)
cpal.paletteLabels = [C_P_A_L_.table_C_P_A_L_.NO_NAME_ID] * len(palettes)
if paletteEntryLabels is not None:
if len(paletteEntryLabels) != cpal.numPaletteEntries:
raise ColorLibError(
f"Expected {cpal.numPaletteEntries} paletteEntryLabels, "
f"got {len(paletteEntryLabels)}"
cpal.paletteEntryLabels = buildPaletteLabels(paletteEntryLabels, nameTable)
cpal.paletteEntryLabels = [
] * cpal.numPaletteEntries
cpal.version = 0
return cpal
# COLR v1 tables
# See draft proposal at:
def _is_colrv0_layer(layer: Any) -> bool:
# Consider as COLRv0 layer any sequence of length 2 (be it tuple or list) in which
# the first element is a str (the layerGlyph) and the second element is an int
# (CPAL paletteIndex).
layerGlyph, paletteIndex = layer
except (TypeError, ValueError):
return False
return isinstance(layerGlyph, str) and isinstance(paletteIndex, int)
def _split_color_glyphs_by_version(
colorGlyphs: _ColorGlyphsDict,
) -> Tuple[_ColorGlyphsV0Dict, _ColorGlyphsDict]:
colorGlyphsV0 = {}
colorGlyphsV1 = {}
for baseGlyph, layers in colorGlyphs.items():
if all(_is_colrv0_layer(l) for l in layers):
colorGlyphsV0[baseGlyph] = layers
colorGlyphsV1[baseGlyph] = layers
# sanity check
assert set(colorGlyphs) == (set(colorGlyphsV0) | set(colorGlyphsV1))
return colorGlyphsV0, colorGlyphsV1
def _reuse_ranges(num_layers: int) -> Generator[Tuple[int, int], None, None]:
# TODO feels like something itertools might have already
for lbound in range(num_layers):
# Reuse of very large #s of layers is relatively unlikely
# +2: we want sequences of at least 2
# otData handles single-record duplication
for ubound in range(
lbound + 2, min(num_layers + 1, lbound + 2 + _MAX_REUSE_LEN)
yield (lbound, ubound)
class LayerListBuilder:
layers: List[ot.Paint]
reusePool: Mapping[Tuple[Any, ...], int]
tuples: Mapping[int, Tuple[Any, ...]]
keepAlive: List[ot.Paint] # we need id to remain valid
def __init__(self):
self.layers = []
self.reusePool = {}
self.tuples = {}
self.keepAlive = []
# We need to intercept construction of PaintColrLayers
callbacks = _buildPaintCallbacks()
] = self._beforeBuildPaintColrLayers
self.tableBuilder = TableBuilder(callbacks)
def _paint_tuple(self, paint: ot.Paint):
# start simple, who even cares about cyclic graphs or interesting field types
def _tuple_safe(value):
if isinstance(value, enum.Enum):
return value
elif hasattr(value, "__dict__"):
return tuple(
(k, _tuple_safe(v)) for k, v in sorted(value.__dict__.items())
elif isinstance(value,
return tuple(_tuple_safe(e) for e in value)
return value
# Cache the tuples for individual Paint instead of the whole sequence
# because the seq could be a transient slice
result = self.tuples.get(id(paint), None)
if result is None:
result = _tuple_safe(paint)
self.tuples[id(paint)] = result
return result
def _as_tuple(self, paints: Sequence[ot.Paint]) -> Tuple[Any, ...]:
return tuple(self._paint_tuple(p) for p in paints)
# COLR layers is unusual in that it modifies shared state
# so we need a callback into an object
def _beforeBuildPaintColrLayers(self, dest, source):
# Sketchy gymnastics: a sequence input will have dropped it's layers
# into NumLayers; get it back
if isinstance(source.get("NumLayers", None),
layers = source["NumLayers"]
layers = source["Layers"]
# Convert maps seqs or whatever into typed objects
layers = [self.buildPaint(l) for l in layers]
# No reason to have a colr layers with just one entry
if len(layers) == 1:
return layers[0], {}
# Look for reuse, with preference to longer sequences
# This may make the layer list smaller
found_reuse = True
while found_reuse:
found_reuse = False
ranges = sorted(
key=lambda t: (t[1] - t[0], t[1], t[0]),
for lbound, ubound in ranges:
reuse_lbound = self.reusePool.get(
self._as_tuple(layers[lbound:ubound]), -1
if reuse_lbound == -1:
new_slice = ot.Paint()
new_slice.Format = int(ot.PaintFormat.PaintColrLayers)
new_slice.NumLayers = ubound - lbound
new_slice.FirstLayerIndex = reuse_lbound
layers = layers[:lbound] + [new_slice] + layers[ubound:]
found_reuse = True
# The layer list is now final; if it's too big we need to tree it
is_tree = len(layers) > MAX_PAINT_COLR_LAYER_COUNT
layers = _build_n_ary_tree(layers, n=MAX_PAINT_COLR_LAYER_COUNT)
# We now have a tree of sequences with Paint leaves.
# Convert the sequences into PaintColrLayers.
def listToColrLayers(layer):
if isinstance(layer,
return self.buildPaint(
"Format": ot.PaintFormat.PaintColrLayers,
"Layers": [listToColrLayers(l) for l in layer],
return layer
layers = [listToColrLayers(l) for l in layers]
# No reason to have a colr layers with just one entry
if len(layers) == 1:
return layers[0], {}
paint = ot.Paint()
paint.Format = int(ot.PaintFormat.PaintColrLayers)
paint.NumLayers = len(layers)
paint.FirstLayerIndex = len(self.layers)
# Register our parts for reuse provided we aren't a tree
# If we are a tree the leaves registered for reuse and that will suffice
if not is_tree:
for lbound, ubound in _reuse_ranges(len(layers)):
self.reusePool[self._as_tuple(layers[lbound:ubound])] = (
lbound + paint.FirstLayerIndex
# we've fully built dest; empty source prevents generalized build from kicking in
return paint, {}
def buildPaint(self, paint: _PaintInput) -> ot.Paint:
return, paint)
def build(self) -> Optional[ot.LayerList]:
if not self.layers:
return None
layers = ot.LayerList()
layers.LayerCount = len(self.layers)
layers.Paint = self.layers
return layers
def buildBaseGlyphPaintRecord(
baseGlyph: str, layerBuilder: LayerListBuilder, paint: _PaintInput
) -> ot.BaseGlyphList:
self = ot.BaseGlyphPaintRecord()
self.BaseGlyph = baseGlyph
self.Paint = layerBuilder.buildPaint(paint)
return self
def _format_glyph_errors(errors: Mapping[str, Exception]) -> str:
lines = []
for baseGlyph, error in sorted(errors.items()):
lines.append(f" {baseGlyph} => {type(error).__name__}: {error}")
return "\n".join(lines)
def buildColrV1(
colorGlyphs: _ColorGlyphsDict,
glyphMap: Optional[Mapping[str, int]] = None,
) -> Tuple[Optional[ot.LayerList], ot.BaseGlyphList]:
if glyphMap is not None:
colorGlyphItems = sorted(
colorGlyphs.items(), key=lambda item: glyphMap[item[0]]
colorGlyphItems = colorGlyphs.items()
errors = {}
baseGlyphs = []
layerBuilder = LayerListBuilder()
for baseGlyph, paint in colorGlyphItems:
baseGlyphs.append(buildBaseGlyphPaintRecord(baseGlyph, layerBuilder, paint))
except (ColorLibError, OverflowError, ValueError, TypeError) as e:
errors[baseGlyph] = e
if errors:
failed_glyphs = _format_glyph_errors(errors)
exc = ColorLibError(f"Failed to build BaseGlyphList:\n{failed_glyphs}")
exc.errors = errors
raise exc from next(iter(errors.values()))
layers =
glyphs = ot.BaseGlyphList()
glyphs.BaseGlyphCount = len(baseGlyphs)
glyphs.BaseGlyphPaintRecord = baseGlyphs
return (layers, glyphs)
def _build_n_ary_tree(leaves, n):
"""Build N-ary tree from sequence of leaf nodes.
Return a list of lists where each non-leaf node is a list containing
max n nodes.
if not leaves:
return []
assert n > 1
depth = ceil(log(len(leaves), n))
if depth <= 1:
return list(leaves)
# Fully populate complete subtrees of root until we have enough leaves left
root = []
unassigned = None
full_step = n ** (depth - 1)
for i in range(0, len(leaves), full_step):
subtree = leaves[i : i + full_step]
if len(subtree) < full_step:
unassigned = subtree
while len(subtree) > n:
subtree = [subtree[k : k + n] for k in range(0, len(subtree), n)]
if unassigned:
# Recurse to fill the last subtree, which is the only partially populated one
subtree = _build_n_ary_tree(unassigned, n)
if len(subtree) <= n - len(root):
# replace last subtree with its children if they can still fit
assert len(root) <= n
return root