[Xcb] Any xcb glx working examples?

nulleight nulleight at gmail.com
Fri Jan 11 06:16:47 PST 2008


The code still crashes my xserver if i uncomment it. Is there any code that
actually uses xcb_glx?

Regards, Konstantin.


nulleight wrote:
> 
> Hi, I'm a guy who originally wrote this example and I found this forum
> while checking out if someone made my or similar code to work. I am
> running gentoo ~x86 everything compiled with "-O2 -pipe".
> xorg-server is ver.  1.4.0.90 and xcb 1.1. I tried this example also from
> time to time on older versions of xserver and xcb with the same result.
> This problem was not critical for me so i stayed with xlib code and It
> still works, which is also one of the reasons I haven't tried to debug
> xserver(it would take me probably a great deal of time just to become
> familiar with it).  Anyway it would be interesting if someone from the
> more knowledgeble people would try the code out. I swapped out glxflush
> for glxfinish and tried to check for glx errors but it didn't change
> anything. I will try to uncommend the old code and see if it'll crash my
> xserver and report latelty. I'll send the example as an attachment. There
> are also kdevelop project files included.
> 
>  http://www.nabble.com/file/p14755626/glxexample.7z glxexample.7z 
> 
> Jeremy Kolb wrote:
>> 
>> Adam Burton wrote:
>>> Hi,
>>> So far the only example I found is this,
>>> http://lists.freedesktop.org/archives/xcb/2007-July/002948.html
>>> which doesn't appear to work (although I see no reason why). If you look
>>> at 
>>> the source it attempts to get gl errors (commented out) which crashes
>>> the 
>>> XServer, I can confirm the same happens to me (in 1.0 and 1.1), in fact
>>> it 
>>> also happens when using xcb_glx_finish.
>>> Using the x.h and x.c of the above example I converted the following ibm
>>> glx 
>>> example to xcb and I run into the same problem (have attached my code).
>>> http://publib.boulder.ibm.com/infocenter/systems/index.jsp?topic=/com.ibm.aix.opengl/doc/openglrf/HowRenderXdraw.htm
>>> 
>>> I realise the glx guy is on vacation so I don't expect a speedy response
>>> but 
>>> any assistance is appreciated.
>>> 
>>> Regards,
>>> Adam
>>> 
>>> 
>>> ------------------------------------------------------------------------
>>> 
>>> #include "GL/gl.h"
>>> #include "x.h"
>>> 
>>> static int AttributeList[] = { GLX_RGBA, 0 };
>>> 
>>> xcb_glx_context_t glxcontext;
>>> xcb_colormap_t    xcolormap;
>>> xcb_window_t      xwindow;
>>> xcb_glx_window_t  glxwindow;
>>> xcb_glx_context_tag_t glxcontext_tag;
>>> int32_t screen_number;
>>> xcb_connection_t* xconnection;
>>> xcb_screen_t* xscreen;
>>> 
>>> void setup_glx13() {
>>> 	/* Find a FBConfig that uses RGBA.  Note that no attribute list is */
>>> 	/* needed since GLX_RGBA_BIT is a default attribute.*/
>>> 	    uint32_t glxattribs[] = {
>>>                                 GLX_DOUBLEBUFFER, 1,
>>>                                 GLX_RED_SIZE, 8,
>>>                                 GLX_GREEN_SIZE, 8,
>>>                                 GLX_BLUE_SIZE, 8,
>>>                                 GLX_ALPHA_SIZE, 8,
>>>                                 GLX_STENCIL_SIZE, 8,
>>>                                 GLX_DEPTH_SIZE, 24,
>>>                                 GLX_BUFFER_SIZE, 32,
>>>                                 GLX_RENDER_TYPE, GLX_RGBA_BIT,
>>>                                 GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT |
>>> GLX_PIXMAP_BIT | GLX_PBUFFER_BIT,
>>>                                 GLX_X_RENDERABLE, true
>>>                             };
>>> 
>>> 	xcb_glx_fbconfig_t fbconfig = glx_choose_fbconfig( xconnection,
>>> screen_number, glxattribs, sizeof(glxattribs)/2/sizeof(uint32_t));
>>> 	xcb_visualid_t glxvisual = get_attrib_from_fbconfig( xconnection,
>>> screen_number, fbconfig, GLX_VISUAL_ID );
>>> 
>>> 	/* Create a GLX context using the first FBConfig in the list. */
>>> 	xcb_glx_create_new_context( xconnection, glxcontext, fbconfig,
>>> screen_number, GLX_RGBA_TYPE, 0, true, 0, 0 );
>>> 
>>> 	/* Create a colormap */
>>> 	xcb_create_colormap( xconnection , XCB_COLORMAP_ALLOC_NONE, xcolormap,
>>> xscreen->root, glxvisual );
>>> 
>>> 	/* Create a window */
>>> 	uint32_t value_list[2], value_mask = XCB_CW_BACK_PIXEL |
>>> XCB_CW_COLORMAP ;
>>>     value_list[0] = xscreen->white_pixel;
>>>     value_list[1] = xcolormap;
>>> 
>>>     xcb_create_window( xconnection, xscreen->root_depth, xwindow,
>>> xscreen->root, 0, 0, 100, 100, 0,
>>>                                                            
>>> XCB_WINDOW_CLASS_INPUT_OUTPUT,
>>>                                                             glxvisual,
>>>                                                             value_mask,
>>>                                                             value_list
>>> );
>>>     xcb_map_window( xconnection, xwindow );
>>> 	/* Create a GLX window using the same FBConfig that we used for the */
>>> 	/* the GLX context.                                                 */
>>> 	xcb_glx_create_window( xconnection, screen_number, fbconfig, xwindow,
>>> glxwindow, 0, 0);
>>> 	/* Connect the context to the window for read and write */
>>>     xcb_glx_make_context_current_reply_t* reply_ctx =
>>> xcb_glx_make_context_current_reply ( xconnection,
>>> xcb_glx_make_context_current( xconnection, 0, glxwindow, glxwindow,
>>> glxcontext ), 0);
>>> 	glxcontext_tag = reply_ctx->context_tag;
>>> }
>>> 
>>> int main(int argc, char **argv) {
>>> 
>>>     xconnection = xcb_connect( NULL, &screen_number );
>>> 
>>>     // getting the default screen
>>>     xscreen = xcb_setup_roots_iterator( xcb_get_setup( xconnection
>>> )).data;
>>> 
>>> 	glxcontext = xcb_generate_id( xconnection );
>>> 	xcolormap  = xcb_generate_id( xconnection );
>>> 	xwindow    = xcb_generate_id( xconnection );
>>> 	glxwindow  = xcb_generate_id( xconnection );
>>> 
>>> 	setup_glx13();
>>> 	xcb_flush(xconnection);
>>> 	/* clear the buffer */
>>> 	glClearColor(1,1,0,1);
>>> 	glClear(GL_COLOR_BUFFER_BIT);
>>> 	glFlush();
>>> 
>>> 	//This kills xserver
>>> 	//xcb_glx_finish_reply_t* reply = xcb_glx_finish_reply(xconnection,
>>> xcb_glx_finish (xconnection, glxcontext_tag), 0);
>>> 
>>> 	xcb_glx_swap_buffers( xconnection, glxcontext_tag, glxwindow );
>>> 
>>> 	/* wait a while */
>>> 	sleep(10);
>>> }
>>> 
>>> 
>>> ------------------------------------------------------------------------
>>> 
>>> _______________________________________________
>>> Xcb mailing list
>>> Xcb at lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/xcb
>> 
>> My guess on the crash is that instead of doing xcb_glx_finish you
>> probably need to do glFinish as it probably does things that
>> xcb_glx_finish doesn't do.  Also what are you using for GL
>> (mesa/nvidia/fglrx)?  You'll have better luck if you stick to mesa
>> indirect rendering, probably compiled xcb support.
>> 
>> Jeremy
>> _______________________________________________
>> Xcb mailing list
>> Xcb at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/xcb
>> 
>> 
> 
> 

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