948470 - the surface format of a SourceSurface is not always the one of its DataSurface

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Nicolas Silva [:nical]]

I ran into this with the following code

// with a D2D DrawTarget dt which format is A8
RefPtr<SourceSurface> snapshot = dt->Snapshot(); // snapshot is A8
RefPtr<DataSourceSurface> dataSurface = snapshot->GetDataSurface(); // BGRA


Visual studio tells me that the types of the objects are:
dt: D2DDrawTarget
snapshot: SourceSurfaceD2DDrawTarget
dataSurface: DataSourceSurfaceD2DDrawTarget

I don't know if we can assume that GetDataSurface returns something with the same format, or if it is okay to return a surface BGRA from an A8 one, but in my own selfish use case it triggers very slow code paths.

Comment 1

[Nicolas Silva [:nical]]

Attachment: Set the format of DataSourceSurfaceD2DDrawTarget

Comment 2

[Matt Woodrow (:mattwoodrow)]

This seems like a nice invariant to have. If there aren't technical reasons to need different formats, then we should definitely do this.

Comment 3

[Nicolas Silva [:nical]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/f0dc92f252c9

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/f0dc92f252c9