Blink Compositor Promotion of CSS Animations
Blink2866 Marras 2025

Blink Compositor Promotion of CSS Animations

The technical sources provide an extensive analysis of how the Blink rendering engine (used in Chromium/Chrome) determines whether a CSS animation can be executed on the compositor thread instead of the main thread to improve performance and achieve smooth frame rates. This process involves a complex pipeline, beginning with style calculation and proceeding through layout and layer assignment, where an element must be assigned a composited layer and corresponding property tree nodes to be eligible for acceleration. The critical decision is made by the function CheckCanStartAnimationOnCompositor(), which only permits animations on a limited set of properties—primarily transform, opacity, filter, and backdrop-filter—while rejecting anything affecting layout or requiring frame-by-frame repainting. If accelerated, the animation’s keyframes are converted into CompositorAnimation objects and run by the GPU-assisted compositor, allowing the main thread to remain free for other tasks.

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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

cc::LayerTreeHostImpl (Input Handler & Scroll Logic)

cc::LayerTreeHostImpl (Input Handler & Scroll Logic)

Scroll processing and overscroll detection in the compositor. The LayerTreeHostImpl in cc implements the compositor-thread InputHandler that processes gesture scroll updates and flings. It manages the...

23 Syys 202527min