1600593 - Remove generic snap offset references from shaders

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, task, P3)

Description

[Andrew Osmond [:aosmond] (he/him)]

We no longer do post-snapping in the shaders. The inherent assumption is that most points and rects should already be snapped. There are exceptions, such as text, but it now follows the same model as everything else -- it pre-snaps first, and then can interact with other rects (such as clips) in the system. This was replaced by pre-snapping during scene building.

Comment 1

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1600593 - Remove snap offset references from the shaders.

We now assume that most snapping is done during scene building. This
means that nearly every point and rect used in the shaders are
pre-snapped and nothing more need be done. The text shader is an
exception, but it also effectively pre-snaps because when it calculates
its local rect for a glyph, it takes into account any snapping
requirements, rather than adjusting for snapping after its local rect
interacts with other elements.

As such, we can remove any need for generic snap offsets from the
shaders.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/984c5853985b
Remove snap offset references from the shaders. r=kvark

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/984c5853985b