1072138 - Rendered scene not presented correctly on framebuffer

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: General, defect)

Description

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Attachment: Screen capture

See the attached screen capture.  What Gecko is /trying/ to draw is a single color layer (in this case, greenish color).  This is done with a dead-simple shader program.  What /actually/ gets drawn is this strange banded pattern that's mostly black.  The pattern of banding seems entirely deterministic.

Because gecko isn't using any explicit intermediate buffers, the bug here must lie in the GL stack.  It seems most likely to me that we're not flushing video memory at the right point in the pipeline.  It's also possible that the framebuffer isn't configured correctly, but a related bug (forthcoming) makes me think the former is more likely.

Comment 1

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

I found incidentally while working on bug 1072145 that running a test page with a single ColorLayer actually renders properly when GL_DEBUG is enabled, and a glFlush() is added just before the error-checking glFinish().  I don't exactly know what that implies yet, but it's interesting to note.  (And of course glflush+glfinish should == glfinish.)

Comment 2

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

WONTFIX'ing because I couldn't resolve the issues in this stack, and there's no long-term support plan for the code.