[cairo] Threaded animation with cairo_gl backend over a GtkWidget

Sat Feb 2 08:55:15 PST 2013

On Sat, Jan 19, 2013 at 10:53 PM, Andrea Canciani <ranma42 at gmail.com> wrote:
> On Wed, Jan 16, 2013 at 12:55 AM, Henry (Yu) Song - SISA
> <hsong at sisa.samsung.com> wrote:
>> I also created a cairo to NSOpenGLContext binding such that you don't need
>> glx, gtk on mac, you can use cocoa directly.  It is located
>> https://github.com/csyuschmjuh/cairo-nsgl, I need someone to test/confirm
>> its is working - NSView is working, but not implemented for virtual screen
>> yet.
>
> Wouldn't it be better to bind it to CoreGL?
> It is lower level (in fact NSOpenGLContext is based on it, you can
> even get the underlying CGL context using the CGLContextObj selector)
> and it has primitives which are easier to map to cairo-gl.
> The documentation is available here:
> https://developer.apple.com/library/mac/#documentation/graphicsimaging/Reference/CGL_OpenGL/Reference/reference.html#//apple_ref/doc/uid/TP40001186
>

I finally had some time to try CGL.
The result is the branch
http://cgit.freedesktop.org/~ranma42/cairo/log/?h=wip/cgl

Andrea

>>
>> To compile for nsopengl on mac "./configure --prefix=/your_install_directory
>> --enable-gl=yes --enable-glx=no --enable-nsgl=yes"
>>
>> To compile for glx on mac "./configure --prefix=/your_install_directory
>> --enable-gl=yes"
>>
>> Attached is the cocoa-based sample code with cairo. compile it with "gcc -o
>> cairo-nsgl-fill cairo-nsgl-fill.m `pkg-config --libs --cflags cairo`
>> -framework OpenGL -framework AppKit"
>
> I will try ASAP.
> I'm still very busy with my PhD, but I'm trying to catch up with the
> cairo/pixman-related mail and work I left behind.
>
>>
>> Thanks
>>
>> Henry
>>
>> ________________________________
>> From: cairo-bounces+hsong=sisa.samsung.com at cairographics.org
>> [cairo-bounces+hsong=sisa.samsung.com at cairographics.org] on behalf of Henry
>> (Yu) Song - SISA [hsong at sisa.samsung.com]
>> Sent: Tuesday, January 15, 2013 3:43 PM
>> To: Carlos López González
>>
>> Cc: cairo at cairographics.org
>> Subject: Re: [cairo] Threaded animation with cairo_gl backend over a
>> GtkWidget
>>
>> You are using a driver that does not support window/pixmap multisampling.
>> Remove GLX_SAMPLE_BUFFERS and GLX_SAMPLES, that should work for you.
>>
>> cairo-gles supports both glx/gl and egl/gles.  You still can use MSAA for
>> rendering to texture, but you will fallback to spans/traps compositors for
>> rendering to pixmap/window because your driver does not support msaa on
>> window/pixmap.
>>
>> In your sample, you are creating a texture-based gl_surface, I am not sure
>> what kind of surface is created by gdk binding to cairo - most likely it is
>> an image surface.  in that case, you will get a performance hit by
>> downloading texture to image in system memory.
>>
>> Henry
>>
>>
>> ________________________________
>> From: Carlos López González [genetita at gmail.com]
>> Sent: Tuesday, January 15, 2013 3:04 PM
>> To: Henry (Yu) Song - SISA
>> Cc: cairo at cairographics.org
>> Subject: Re: [cairo] Threaded animation with cairo_gl backend over a
>> GtkWidget
>>
>> The code modifications applied to the laptop gives a null surface because
>> glXChooseVisual returns a NULL pointer when creating the XVisualInfo for the
>> modified attributes. Possibly my graphic card doesn't support those
>> requirements.
>> Attached are the glxinfo output and the interesting line from lspci.
>> I'll test it on OSX tomorrow.
>> Thanks!
>>
>>
>> 2013/1/15 Carlos López González <genetita at gmail.com>
>>>
>>> Hi Henry,
>>> thank you very much for your detailed reply and the code additions. I'll
>>> give it a try and would let you know the results.
>>> I considered cairogles but isn't it created for embedded systems? When it
>>> were added upstream, would it be suitable to be used in non embedded system?
>>> In case of use cairogles, where can I find its API?
>>> Thanks!
>>>
>>>
>>> 2013/1/15 Henry (Yu) Song - SISA <hsong at sisa.samsung.com>
>>>
>>>> I modified your code a little as attached.  Two changes
>>>>
>>>> 1. add cairo_gl_device_set_thread_aware ()
>>>> 2. add GLX_SAMPLES/GLX_SAMPLE_BUFFER
>>>>
>>>> 1. The first add is to reduce GL context switch if you have dedicated one
>>>> thread for rendering (regardless where you create your gl_surface).  If you
>>>> have multiple threads that render to the same gl surface, you cannot
>>>> set_thread_aware (device, FALSE)
>>>>
>>>> 2. If your driver (proprietary nvidia, fglrx and latest intel (mesa >
>>>> 9.0) on sandbridge/ivybridge) supports MSAA, you might want to try our new
>>>> cairo which uses MSAA for antialiasing. It is at
>>>> http://code.google.com/p/cairogles.  It is faster than gl backend in the
>>>> cairo upstream and we are in process of upstreaming it.  It is also more
>>>> stable.  If you want to MSAA on window/pixmap, you need to add GLX_SAMPLES
>>>> and GLX_SAMPLE_BUFFERS to your glx attrib.  If you want to experiment more
>>>> complex drawing, I recommend you use our gles, it is more stable and fast (I
>>>> think it is the fastest backend at this moment given your driver supports
>>>> MSAA, and you don't want to have ANTIALIAS_BEST/subpixel). When you use our
>>>> cairogles, please set CAIRO_GL_COMPOSITOR=msaa in your environment.
>>>>
>>>> 3. There is a caveat when you are using gl surface in cairo at this
>>>> moment.  You need to dedicate a gl context to cairo.  You cannot interleave
>>>> cairo with gl calls/or other library that uses the same gl context as cairo.
>>>> If you do that, you MUST same context/drawable/any other GL states before
>>>> you call gl directly and you MUST restore these before you enter cairo
>>>> drawing.
>>>>
>>>> Let me how pixman compare to gl in your test case,  Don't have
>>>> radeon/nouveau drivers, not sure how they turn out.
>>>>
>>>> Henry
>>>> ________________________________________
>>>> From: cairo-bounces+hsong=sisa.samsung.com at cairographics.org
>>>> [cairo-bounces+hsong=sisa.samsung.com at cairographics.org] on behalf of Carlos
>>>> López González [genetita at gmail.com]
>>>> Sent: Tuesday, January 15, 2013 11:39 AM
>>>> To: cairo at cairographics.org
>>>> Subject: Re: [cairo] Threaded animation with cairo_gl backend over a
>>>> GtkWidget
>>>>
>>>> Hi!
>>>> I've modified the mentioned Cairo animation with miltithreading example
>>>> [1] to use a cairo_gl_surface, expecting to have some GPU acceleration. It
>>>> works fine (doesn't crash) but when I use a cairo_gl_surface it runs much
>>>> slow than when I use a image surface (!). See code here:
>>>>
>>>> https://github.com/genete/my-test-area/blob/direct_draw/src/cairo_sample.c
>>>>
>>>> commenting the line at 135 and 137 I can use cairo_image or cairo_gl.
>>>>
>>>> Same code has been compiled and run in a iMac 2011 using XQuarz as
>>>> Xserver with the same result.
>>>>
>>>> Am I missing something at the cairo_gl code or simply I would never could
>>>> make use of my GPU in my linux laptop or my iMac?
>>>>
>>>> I appreciate any help.
>>>> Thanks!
>>>>
>>>> [1] http://cairographics.org/threaded_animation_with_cairo/
>>>>
>>>> 2013/1/15 Carlos López González
>>>> <genetita at gmail.com<mailto:genetita at gmail.com>>
>>>> I forgot to CC cairo list
>>>>
>>>> ---------- Forwarded message ----------
>>>> From: Carlos López González
>>>> <genetita at gmail.com<mailto:genetita at gmail.com>>
>>>> Date: 2013/1/15
>>>> Subject: Re: [cairo] Threaded animation with cairo_gl backend over a
>>>> GtkWidget
>>>> To: Uli Schlachter <psychon at znc.in<mailto:psychon at znc.in>>
>>>>
>>>>
>>>> Hi!
>>>> I've upgraded to Ubuntu 12.10 and as part of the upgrade Ubuntu disabled
>>>> the proprietary nvidia driver.
>>>> With the  the nouveau driver enabled and simply enable multithreading, it
>>>> crash.
>>>>
>>>> carlos at laptop:~/my-test-area/build$ LANG=C ./cairo-sample
>>>> [xcb] Unknown request in queue while dequeuing
>>>> [xcb] Most likely this is a multi-threaded client and XInitThreads has
>>>> not been called
>>>> [xcb] Aborting, sorry about that.
>>>> cairo-sample: ../../src/xcb_io.c:178: dequeue_pending_request: Assertion
>>>> `!xcb_xlib_unknown_req_in_deq' failed.
>>>> Abortado (`core' generado)
>>>>
>>>> But when add XIniThreads()  as shown in the previous post, it doesn't
>>>> crash but it runs *extremely* slow (?). I'm using a GeForce 8400M GS graphic
>>>> card (glxgears runs smoothly).
>>>>
>>>> If I enable the private nvidia-current driver it crashes in any case with
>>>> the same message than I had before. The suggested breakpoint or the --sync
>>>> option doesn't help much.
>>>>
>>>> So which are my alternatives?
>>>>
>>>> If I create the cairo_gl_surface but not using
>>>> cairo_gl_surface_create_for_window but the cairo_gl_create_surface, would it
>>>> have GPU acceleration as well?
>>>>
>>>> I just want to create a minimal example of multithreading drawing over a
>>>> gtkwidget using cairo_gl to later translate to a bigger application, but it
>>>> seems that it is impossible.
>>>>
>>>> Is there any *real* application that uses Cairo with GPU acceleration in
>>>> production?
>>>>
>>>> Thanks!
>>>>
>>>>
>>>> 2013/1/14 Uli Schlachter <psychon at znc.in<mailto:psychon at znc.in>>
>>>> Hi,
>>>>
>>>> On 14.01.2013 21:24, Carlos López González wrote:
>>>> [...]
>>>> > The program 'cairo-sample' received an X Window System error.
>>>> > This probably reflects a bug in the program.
>>>> > The error was 'BadMatch (invalid parameter attributes)'.
>>>> >   (Details: serial 230 error_code 8 request_code 135 minor_code 5)
>>>>
>>>> minor_code 5 likely is DRI2's GetBuffer request, but could also be a
>>>> RANDRGetScreenInfo, RenderChangePicture, SHAPEQueryExtents,
>>>> SHMCreatePixmap or
>>>> SyncQueryCounter. Of course, this doesn't really help us (does it?).
>>>>
>>>> [...]
>>>> >   (Note to programmers: normally, X errors are reported asynchronously;
>>>> >    that is, you will receive the error a while after causing it.
>>>> >    To debug your program, run it with the --sync command line
>>>> >    option to change this behavior. You can then get a meaningful
>>>> >    backtrace from your debugger if you break on the gdk_x_error()
>>>> > function.)
>>>>
>>>> do "break gdk_x_error" before you "run" the program.
>>>>
>>>> > [Thread 0xb4738b40 (LWP 3625) exited]
>>>> > [Thread 0xb54ffb40 (LWP 3624) exited]
>>>> > [Thread 0xb6224880 (LWP 3620) exited]
>>>> > [Inferior 1 (process 3620) exited with code 01]
>>>> > (gdb) where
>>>> > No stack.
>>>> > (gdb)
>>>> >
>>>> >
>>>> > How can I add the --sync option?
>>>>
>>>> If the program supports this option: "run --sync".
>>>>
>>>> Uli
>>>> --
>>>> "Why make things difficult, when it is possible to make them cryptic
>>>> and totally illogical, with just a little bit more effort?" -- A. P. J.
>>>> --
>>>> cairo mailing list
>>>> cairo at cairographics.org<mailto:cairo at cairographics.org>
>>>> http://lists.cairographics.org/mailman/listinfo/cairo
>>>>
>>>>
>>>>
>>>> --
>>>> Carlos
>>>> http://synfig.org
>>>>
>>>>
>>>>
>>>> --
>>>> Carlos
>>>> http://synfig.org
>>>>
>>>>
>>>>
>>>> --
>>>> Carlos
>>>> http://synfig.org
>>>
>>>
>>>
>>>
>>> --
>>> Carlos
>>> http://synfig.org
>>
>>
>>
>>
>> --
>> Carlos
>> http://synfig.org
>>
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>> cairo mailing list
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