cc::TransformTree

source provides a highly detailed technical overview of the Transform Property Tree within the Chromium compositor, which is a core component of the RenderingNG architecture responsible for all coordinate transformations and geometric calculations. This structure uses TransformNode entries to represent individual coordinate spaces, enabling the efficient computation and caching of transforms such as to_parent (local transform to the parent) and to_screen (global transform to the root viewport). Critically, the TransformTree handles complex visual features like CSS transforms, scrolling (treating offsets as translation matrices), 3D contexts and flattening, and pixel snapping to ensure visual precision, all while propagating animation status and damage tracking to minimize recalculations and allow off-main-thread updates.