cc Transform and Scroll Trees
Blink28628 Syys 2025

cc Transform and Scroll Trees

The source text details the architecture of Chromium's compositor, focusing on the tandem operation of two critical data structures: the Transform Tree and the Scroll Tree. The Transform Tree manages visual coordinate space transformations, including CSS transforms and scroll offsets, with each TransformNode calculating its final position relative to its parent using local matrices and the scroll translation. In parallel, the Scroll Tree, composed of ScrollNodes, handles the logical state of scrollable elements, defining constraints like scrollable bounds, allowed directions, and scroll chaining behavior. Crucially, the sources explain that the two trees are linked via a shared ElementId and that while the Scroll Tree determines how a scroll should happen (bounds and policy), the Transform Tree executes the change by holding and applying the live scroll_offset to visually move the layer content, enabling smooth, composite-threaded scrolling.

Jaksot(417)

Chrome Compositor Transform Updates on Scroll

Chrome Compositor Transform Updates on Scroll

These sources provide an extensive technical explanation of how the Chrome compositor manages dynamic properties, specifically focusing on transformations and scrolling, using a structure called Prope...

4 Loka 202532min

Chrome Compositor Architecture: LayerTreeHost and LayerTreeHostImpl

Chrome Compositor Architecture: LayerTreeHost and LayerTreeHostImpl

The sources provide an extensive architectural overview of the Chrome cc compositor module, focusing on the collaboration between three critical classes: LayerTreeHost (LTH), LayerTreeHostImpl (LTHI),...

3 Loka 202534min

Chromium Blink's Layer Recycle Tree Optimization

Chromium Blink's Layer Recycle Tree Optimization

The sources provide an extensive technical explanation of the Chromium/Blink rendering pipeline, focusing specifically on the compositor's layer trees and a performance optimization known as the Recyc...

3 Loka 202529min

Chromium Compositor's CalculateDrawProperties: Scrolling and Overscroll

Chromium Compositor's CalculateDrawProperties: Scrolling and Overscroll

The sources provide an extremely detailed, line-by-line breakdown of the Chromium compositor function CalculateDrawProperties, explaining how it prepares the active layer tree for rendering. A primary...

3 Loka 202530min

Git Rebase and Interactive Rebase for Chromium Development

Git Rebase and Interactive Rebase for Chromium Development

The sources provide a comprehensive guide to Git rebasing and interactive rebasing, explaining how these powerful tools rewrite commit history to maintain a clean, linear project record. They detail t...

2 Loka 202536min

Chrome Finch System Technical Guide and Rollouts

Chrome Finch System Technical Guide and Rollouts

The source text provides an exhaustive technical guide to Chrome’s Finch (Variations) system, a mechanism used for running field trials and A/B experiments to control browser features remotely. This s...

1 Loka 20251h 14min

Chromium Compositor Input: Handler and Proxy Deep Dive

Chromium Compositor Input: Handler and Proxy Deep Dive

The source provides a detailed technical analysis of how the Chromium web browser manages user input to ensure a responsive and smooth user experience, even when the main thread is occupied. It center...

1 Loka 202531min

Current Overscroll System Architecture Deep Dive

Current Overscroll System Architecture Deep Dive

The provided document offers an in-depth technical architectural overview of the overscroll system, primarily within the Chromium browser. It explains how browsers handle scroll gestures that go beyon...

29 Syys 202535min