blink::PaintArtifactCompositor
Blink28610 Loka 2025

blink::PaintArtifactCompositor

turns chunks into compositor layers & updates cc property trees.

Consumes the new PaintArtifact and does the layerization and property‑tree updates required for compositor draw. It supports fast paths when only values changed (e.g., opacity) or when a scroll only induces raster invalidation, avoiding full rebuilds. It owns a subtree of cc layers corresponding to the artifact. (Chromium Git Repositories)

Key fields

  • scoped_refptr<cc::Layer> root_layer_ — root of the Blink‑owned layer subtree.

  • UpdateType needs_update_ — kRepaint vs kFull (or scroll fast path).

  • Caches/maps for synthesized mask clips and scroll translations seen while layerizing. (Chromium Git Repositories)

Most important methods

  • bool TryFastPathUpdate(const PaintArtifact&) — take a cheap path (no topology change). (Chromium Git Repositories)

  • void Update(const PaintArtifact&, const ViewportProperties&, const StackScrollTranslationVector&, Vector<std::unique_ptr<cc::ViewTransitionRequest>>) — full reconciliation to layers + cc property trees. (Chromium Git Repositories)

  • “Direct update” helpers like DirectlyUpdateCompositedOpacityValue(...), DirectlyUpdateScrollOffsetTransform(...) — skip rebuilds for common animations/scrolling. (Chromium Git Repositories)

Hands off to: PropertyTreeManager (internally) to mirror Blink property nodes to cc trees, ready for commit to the compositor thread.


Jaksot(394)

Animation Pipeline: Main Thread to Compositor

Animation Pipeline: Main Thread to Compositor

The sources provide an extensive architectural overview of the Chromium animation pipeline, detailing the complex process required to accelerate animations by moving them off the main thread onto the ...

25 Syys 202536min

cc::CommitState

cc::CommitState

The provided source offers an extensive architectural analysis of Chromium’s cc::CommitState struct, detailing its critical function as the intermediary data structure that facilitates communication b...

25 Syys 202540min

Blink and Compositor Stacking Contexts

Blink and Compositor Stacking Contexts

These sources provide an extensive technical explanation of how CSS stacking contexts are implemented within the Chromium rendering engine, focusing on the collaboration between the Blink renderer and...

25 Syys 202538min

Chromium Architecture: Input, Synchronization, and Animation Pipelines

Chromium Architecture: Input, Synchronization, and Animation Pipelines

These sources provide an extensive architectural overview of the core C++ classes that implement Chromium's input handling, synchronization, and animation systems. The documents detail the multi-proce...

25 Syys 202540min

CSS View Transition Pseudo-elements Explained

CSS View Transition Pseudo-elements Explained

These sources provide a detailed, technical explanation of the View Transition API implementation within the Chromium web browser, focusing on how CSS pseudo-elements enable smooth animations. The fir...

24 Syys 202538min

gpu::SkiaOutputSurfaceImplOnGpu / gpu::CommandBuffer

gpu::SkiaOutputSurfaceImplOnGpu / gpu::CommandBuffer

Bridges Skia’s recorded commands to the GPU command buffer; submits and SwapBuffers to present. (Backend: GL/Vulkan/Metal via GPU process.)

23 Syys 202532min

viz::SkiaRenderer

viz::SkiaRenderer

Renderer that turns quads into Skia operations (recording DDLs / drawing to the output surface).

23 Syys 202552min

viz::Display

viz::Display

The display compositor that walks the aggregated render passes and issues draw commands for the final output.

23 Syys 202538min