Hello;
Unfortunately I've noticed a problem with the implementation. Native
client expects 3D API to be used so that caller passes a callback that
gets called when swapbuffers finishes. I haven't found explicit
documentation of this to be *mandatory* but all the examples work this
way and lots of comments on different forums suggest to use it like
this. Now what follows is that while current nacl backend takes care
that user cannot 'bomb' swapbuffers callback, it cannot take care that
user would not go and call GL API (for example glClear) before
swapbuffers finishes. For this to happen there would need to be callback
mechanism or a new API to call on start of each frame. I'm not yet 100%
sure but I believe this would fix the issues I'm seeing ATM.
I ported es2gears to Waffle to experiment this, here is a version that
shows the problem, the artifacts on top of gears seem to relate to
calling glClear 'too early' as if I remove glClear call it looks good,
just not cleared:
http://koti.kapsi.fi/~tpalli/naclgears-bug/
Here's a hacked version where I sleep (just a tiny bit) between frames
and tadaa it works:
http://koti.kapsi.fi/~tpalli/naclgears/
I'm not yet sure what to do with this, one option would be to offer a
callback mechanism in Waffle ("swap finished") but there are no existing
callbacks like this in waffle. Would it be ok and create something like
this?
Thanks;
On 01/23/2015 09:59 AM, Tapani Pälli wrote:
Hi;
Here are patches for the NaCl backend implementation. While testing I
noticed that there is a general issue with Chrome and DRI3 which is well
described here: http://keithp.com/blogs/chromium-dri3/ . So for testing
on DRI3 you'll need to use '--disable-gpu-sandbox' for this to work.
Otherwise you will see :
libGL error: DRI3 Fence object allocation failure Operation not permitted"
which results in everything else failing, like creation of graphics
context and so on. I haven't checked what's the status of fixing this
but it is good to know when testing. This happened to me on Fedora 21.
The whole series is in a branch here:
http://cgit.freedesktop.org/~tpalli/waffle/log/?h=nacl
and a 'demo' of gl_basic available here:
http://koti.kapsi.fi/~tpalli/nacl/
Note, I will be extending this to support OpenGL ES 3.0 later/soon. I'm
also investigating how to make this work for "portable native client",
pnacl-clang.
Thanks;
Tapani Pälli (7):
nacl: add supports_context_api implementation
nacl: add implementation for waffle_config_choose
nacl: add implementation for waffle_context_create
nacl: add implementation for window create and resize
nacl: add implementation for waffle_make_current
nacl: add implementation for waffle_window_swap_buffers
nacl: add implementation for waffle_dl_sym
src/waffle/nacl/nacl_config.c | 30 ++++++++
src/waffle/nacl/nacl_config.h | 2 +
src/waffle/nacl/nacl_container.cpp | 136 +++++++++++++++++++++++++++++++++++++
src/waffle/nacl/nacl_container.h | 11 +++
src/waffle/nacl/nacl_context.c | 6 ++
src/waffle/nacl/nacl_display.c | 9 ++-
src/waffle/nacl/nacl_platform.c | 65 +++++++++++++++++-
src/waffle/nacl/nacl_platform.h | 1 +
src/waffle/nacl/nacl_swap_thread.h | 72 ++++++++++++++++++++
src/waffle/nacl/nacl_window.c | 10 ++-
src/waffle/nacl/nacl_window.h | 1 +
11 files changed, 337 insertions(+), 6 deletions(-)
create mode 100644 src/waffle/nacl/nacl_swap_thread.h
_______________________________________________
waffle mailing list
waffle@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/waffle
