A tiling-pattern paint in a display list: the pattern, the space it is laid out in, and its cell, already built into a display list of its own. A backend replicates the cell over the painted area at multiples of XStep and YStep. Valid only during the backend call that hands it over (the Cell list itself is immutable and may be kept, like any display list).
public ref readonly struct DisplayTilingPattern
ISO 32000-2 §8.7.3. The cell is the pattern's content stream run as §8.7.3.1 steps a to d say (the graphics state at the beginning of the stream that selected the pattern, alpha constants and blend mode at their defaults as §11.6.7 requires, clipped to the pattern's BBox), recorded relative to pattern space: Cell replays like a page's list, with pattern space as its default user space. An uncoloured pattern's cell (§8.7.3.3) is already painted in the colour given with the pattern, so a backend treats both paint types alike.
The cell is built once per pattern per list (per page): every paint with the same pattern, selected in the same stream and, for an uncoloured pattern, with the same colour, hands over the same Cell instance, so a backend can cache what it makes of it (a tile bitmap, a native pattern) by reference.
Tiles are placed at (i × XStep, j × YStep) in pattern space for every integer i and j, the cell's BoundingBox clipping each one, so a step smaller than the bounding box overlaps neighbouring tiles. TilingType says how a backend may adjust the spacing to the device's pixel grid (Table 74).
kind:method, kind:property, kind:ctor. Press Esc to clear.CellGets the cell: the display list of one tile at the origin of pattern space, clipped to the bounding box.MatrixGets the transform from pattern space to the list's default user space: the pattern matrix followed by the space of the stream that selected the pattern. It does not depend on the transform SetTransform(in Matrix) set.PatternGets the pattern: its bounding box, steps, paint type and tiling type. Always valid.