Clip Nodes in the Blink and Chromium Compositor
Blink2862 Tammi

Clip Nodes in the Blink and Chromium Compositor

The provided text explains how Chromium’s Blink engine and the compositor utilize clip nodes within property trees to manage page geometry and visual masking. These nodes define specific regions where content remains visible, specifically handling CSS overflow, clip-paths, and border-radius through a hierarchical structure. The system differentiates between main-thread clipping, which is flexible but CPU-intensive, and compositor-thread clipping, which leverages the GPU for higher performance during scrolling and animations. By separating clipping into dedicated clip trees, the engine ensures that visual restrictions are applied efficiently without redundant calculations. This architectural approach also facilitates precise hit testing and optimized rasterization by identifying which parts of an element are interactive or visible to the user. Overall, the sources detail the lifecycle of clipping data as it moves from initial layout through pre-paint to final GPU compositing.

Jaksot(403)

blink::TransformPaintPropertyNode / ClipPaintPropertyNode / EffectPaintPropertyNode / ScrollPaintPropertyNode

blink::TransformPaintPropertyNode / ClipPaintPropertyNode / EffectPaintPropertyNode / ScrollPaintPropertyNode

The paint property trees captured during painting (transform, clip, effect/opacity, scroll offset) that define visual & coordinate‑space state.

21 Syys 202541min

blink::PaintController

blink::PaintController

Records drawing into a DisplayItemList, segmenting it into PaintChunks keyed by property‑tree state. (Output: a PaintArtifact.)

21 Syys 202533min

blink::LayoutView (root of the layout tree)

blink::LayoutView (root of the layout tree)

Computes geometry for boxes when layout is dirty.

21 Syys 202539min

blink::StyleEngine / style resolver

blink::StyleEngine / style resolver

Recalculates computed styles that changed since last frame (if any).

21 Syys 202542min

blink::Page → blink::LocalFrame / LocalFrameView

blink::Page → blink::LocalFrame / LocalFrameView

The document’s frame & viewport; LocalFrameView is the scrollable root that triggers layout/paint when needed. provided source outlines the fundamental components of the Blink rendering engine, specif...

21 Syys 202539min

blink::WebViewImpl

blink::WebViewImpl

The source text provides an in-depth explanation of the blink::WebViewImpl class within Chromium's Blink rendering engine, characterizing it as the central control point on the renderer's main thread ...

20 Syys 202539min

cc::LayerTreeHost in Chromium's Compositor

cc::LayerTreeHost in Chromium's Compositor

The source provides an extensive technical explanation of the cc::LayerTreeHost class, which acts as the central main-thread component in the Chromium compositor architecture. It details how this comp...

20 Syys 202537min

cc:: Scheduler / SchedulerStateMachine

cc:: Scheduler / SchedulerStateMachine

Drives the frame loop on the compositor thread (BeginFrame → Animate → Commit → Draw), deciding when to ask Blink for a new frame or to draw with existing state.

20 Syys 202548min