Module variations

Expand description

OpenType font variations common tables.

Structs§

ActiveTupleVariationIter 🔒: An iterator over the active TupleVariations for a specific glyph for a given set of coordinates.
DeltaRunIter: Implements the logic for iterating over the individual runs
DeltaSetIndex: Outer and inner indices for reading from an ItemVariationStore.
EntryFormat: Entry format for a DeltaSetIndexMap.
FloatItemDelta: Floating point item delta computed by an item variation store.
ItemDeltas 🔒
PackedDeltas: Packed Deltas
PackedPointNumbers: Packed “Point” Numbers
PackedPointNumbersIter: An iterator over the packed point numbers data.
PointRunIter 🔒: Implements the logic for iterating over the individual runs
RegionAxisCoordinates: The RegionAxisCoordinates record
Tuple: A Tuple Record
TupleDeltaIter: An iterator over the deltas for a glyph.
TupleIndex
TupleVariation: A single set of tuple variation data
TupleVariationCount: The ‘tupleVariationCount’ field of the Tuple Variation Store Header
TupleVariationData
TupleVariationHeaderIter: A helper type for iterating over TupleVariationHeaders.
TupleVariationIter: An iterator over the TupleVariations for a specific glyph.
VariationRegion: The VariationRegion record

DeltaRunType: The type of values for a given delta run (influences the number of bytes per delta)
DeltaSetIndexMap: The DeltaSetIndexMap table
TupleDeltaValues 🔒

DELTAS_ARE_WORDS 🔒: Flag indicating the data type for delta values in the run.
DELTAS_ARE_ZERO 🔒: Flag indicating that this run contains no data, and that the deltas for this run are all zero.
DELTA_RUN_COUNT_MASK 🔒: Mask for the low 6 bits to provide the number of delta values in the run, minus one.
NO_VARIATION_INDEX

FloatItemDeltaTarget: Trait for applying floating point item deltas to target values.
TupleDelta: Trait for deltas that are computed in a tuple variation store.

advance_delta 🔒
compute_scalar 🔒: Compute the fixed point scalar for this tuple at the given location in variation space.
count_all_deltas 🔒: Counts the number of deltas available in the given data, avoiding excessive reads.
item_delta 🔒
read_control_byte 🔒: returns the count and the ‘uses_two_bytes’ flag from the control byte
read_dense_deltas 🔒: This is basically a manually applied loop unswitching optimization for reading deltas. It reads each typed run into a slice for processing instead of handling each delta individually with all the necessary branching that implies.
read_sparse_deltas 🔒: See read_dense_deltas docs.