Compositor-Only transform/opacity List
Explicit trace-confirmed prerequisites for transform/opacity compositor-only updates; property name alone is not performance/compositing guarantee. Explicit supplied computed/layout context only; not a browser cascade/layout engine or cross-browser guarantee.
Description
Transform and opacity updates can sometimes avoid new raster work.
Transform and opacity updates can sometimes avoid new raster work.1
Independently supplied promotion and invalidation evidence are required instead of assuming compositor-only behavior. Use Compositor-Only transform/opacity List to evaluate the supplied inputs under the specific model below.
When to use Compositor-Only transform/opacity List
Use Compositor-Only transform/opacity List to evaluate the supplied inputs under the specific model below. Define the supplied layout, token or rendering scenario and establish the relevant units and browser context independently.
How to use Compositor-Only transform/opacity List and understand its results
- Define the supplied layout, token or rendering scenario and establish the relevant units and browser context independently.
- Enter Changed property, Independently promoted layer, Independently no raster invalidation using the field table and validation rules below, then run the tool.
- Read Compositor only prerequisites witnessed and interpret units, signs, ordering and placeholders as explained below.
- If the tool reports an input error, correct that field and rerun. A successful false result, empty match list or unknown-evidence placeholder has the specific meaning described here; check the limitations before applying the result.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| changedProperty | Changed property | string | Required; constraints below |
| independentlyPromotedLayer | Independently promoted layer | boolean | Required; constraints below |
| independentlyNoRasterInvalidation | Independently no raster invalidation | boolean | Required; constraints below |
Enter exactly transform or opacity, and caller booleans for compositor promotion and raster reuse. The output is the conjunction of the two booleans; the property token is validated but does not otherwise change that decision. This is a scenario record, not proof of compositor-only execution or a browser profile.
modeledCompositorOnly = independentlyPromoted and rasterReusable Field order, units and branch conditions follow the implementation explanation above.
| Output field | Meaning | Value type |
|---|---|---|
| compositorOnlyPrerequisitesWitnessed | Compositor only prerequisites witnessed | boolean |
{
"input": {
"changedProperty": "transform",
"independentlyPromotedLayer": true,
"independentlyNoRasterInvalidation": true
},
"output": {
"compositorOnlyPrerequisitesWitnessed": true
}
}Limitations and assumptions
Independently supplied promotion and invalidation evidence are required instead of assuming compositor-only behavior. Apply the exact scope and assumptions described above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are stated above; extremely large inputs or outputs can also be rejected. These errors differ from successful results such as false, no matches or unknown evidence.
Alternative or Complementary methods
Use Reflow vs Repaint Trigger Table for a related task: Property changes can invalidate different rendering stages.
Use Layout Thrashing Read/Write Interleave Warning for a related task: A layout-dependent read after an invalidating write can require pending layout work.
References
-
Compositor-Only transform/opacity List — tool.io
Similar or alternative tools
- Reflow vs Repaint Trigger Table
Property changes can invalidate different rendering stages.
- Layout Thrashing Read/Write Interleave Warning
A layout-dependent read after an invalidating write can require pending layout work.