888906 - cannot call DrawWindow to get a HiDPI rendering

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Cameron McCormack (:heycam)]

In my bug 821210 patch to get reftests rendering in their native resolution, I've modified reftest.js to take a snapshot by doing:

  ctx.scale(2, 2);

before the:

  ctx.drawWindow(window, 0, 0, 800, 600, ...flags...);

call.  That would draw the 800x600 CSS pixel window in the 1600x2000 canvas.

Since bug 848482 landed, rather than getting the high resolution window snapshot, I get a scaled up view of an 800x600 rendering of the window (it looks like).  Should that bug have affected whether drawWindow could give me a native resolution rendering of the window?

Comment 1

[Cameron McCormack (:heycam)]

(In reply to Cameron McCormack (:heycam) from comment #0)
> call.  That would draw the 800x600 CSS pixel window in the 1600x2000 canvas.
> 
> Since bug 848482 landed, rather than getting the high resolution window
> snapshot, I get a scaled up view of an 800x600 rendering of the window (it
> looks like).  Should that bug have affected whether drawWindow could give me
> a native resolution rendering of the window?

s/800x600/800x1000/g

Comment 2

[Matt Woodrow (:mattwoodrow)]

Yes, this is a bug.

We want to detect that the destination surface has a scale transform, and move that onto our temporary surface.

We also want to create our temporary surface at the scaled size.

Comment 3

[Cameron McCormack (:heycam)]

Attachment: patch

Comment 4

[Cameron McCormack (:heycam)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/31bd4657ff94

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/31bd4657ff94