One draw of a frame (GetFrame(in Viewport, Span<FramePart>)): a page's paper, or a tile already on the surface, and where it goes in the viewport.
public readonly record struct FramePart(FramePartKind Kind, Tile Tile, LayoutRectangle Destination) : IEquatable<FramePart>
Spec #33 viewer capability 2. Parts come in drawing order (later parts over earlier): every page's paper, then the scaled tiles farthest from the frame's zoom first, then the sharp tiles, so the sharpest pixels end on top.
kind:method, kind:property, kind:ctor. Press Esc to clear.FramePart(FramePartKind, Tile, LayoutRectangle)One draw of a frame (GetFrame(in Viewport, Span<FramePart>)): a page's paper, or a tile already on the surface, and where it goes in the viewport.DestinationWhere it goes, in viewport pixels; it may reach past the viewport's edges, which the shell clips.KindWhat it draws.TileThe tile on the surface to draw (as Present(Tile, Bitmap) received it), stretched from its whole bitmap onto Destination; for Paper, the page's whole render at the frame's zoom (nothing to fetch).