Slimming Paint (a.k.a. Redesigning Painting and Compositing)

Slimming Paint is a Paint team project to re-implement the Blink<->cc picture recording API to work in terms of a global display list rather than a tree of cc::Layers (~aka GraphicsLayer in Blink terminology). It will result in a drastic simplification of the way that composited layers are represented in Blink and cc, which in turn will yield improved performance, correctness and flexibility.

To get a sense of the extent of this rewrite, one side-effect will be the deletion of the code in core/rendering/compositing/.

 

Phases

SlimmingPaintV1 - paint using display items (Status: launched in M45)

SlimmingPaintInvalidation - rewrite of paint invalidation using display items, property trees introduced in blink (Status: launched in M58)

SlimmingPaintV175 - uses property trees for painting in blink, introduces paint chunks, uses paint chunks for raster invalidation (Status: launched in M67)

BlinkGenPropertyTrees - sends a layer list instead of a tree, and generates final property trees in blink instead of re-generating them in cc (Status: launching in M73)

CompositeAfterPaint - compositing decisions made after paint.

 

Presentations

BlinkOn 3.0 Presentation, video (start here to find out more about the project)

 

BlinkOn 4 presentation

 

Blink Property Trees (also reviews the Composite-After-Paint (formerly "SPV2") design)

 

BlinkOn 9 presentation covering current compositing architecture

 

Core team members

Chris Harrelson (chrishtr@), overall TL

Mason Freed (masonfreed@) Blink

Philip Rogers (pdr@) Blink

Stephen Chenney (schenney@) Blink

Xianzhu Wang (wangxianzhu@) Blink

 

Adrienne Walker (enne@) cc

Robert Flack (flackr@) animations

David Bokan (bokan@) viewports

Close relatives

Fredrik Söderquist (fs@opera.com) Blink

Erik Dahlstrom (ed@opera.com) Blink

Florin Malita (fmalita@) Blink / Skia

Mike Klein (mtklein@) Skia

Mike Reed (reed@) Skia

 

 

A number of other people are involved at least tangentially for design discussions and related projects.

Resources and Design Docs

core/paint/README.md

 

Slimming paint invalidation

 

Tracking slimming paint performance

 

Representation and implementation of display lists in Blink

 

Layerization based on display lists

 

Blink paintlist update algorithm details

 

Bounding Rectangle Strategy for Slimming Paint

 

Slimming Paint for UI Compositor

 

Display Item Debugging

 

Some out of date/historical docs are here.