Exporting a GL view is just a nightmare. Things seem to depend upon theused driver. The solutioin I use can be seen athttp://svn.savannah.gnu.org/viewvc/trunk/gchemutils/libs/gcu/glview.cc?annotate=1098&root=gchemutilsstarting from line 368. Not sure it works in all cases. Regards,Jean Le mercredi 26 août 2009 à 15:59 -0400, Lindley M French a écrit :> Well, I've solve the initial issue---I was trying to cast a GdkPixmap when I should have been trying to cast a GdkGLPixmap. The bad cast warning was hidden because I'd forgotten I'd closed stderr on that program.> > However, the images aren't coming out right when the "host window" isn't on-screen. This is odd, since the pixmap is supposed to be sharing lists, textures, etc with the window's context, but not otherwise related to anything on-screen.> > It *looks* to me like what's getting drawn when the window is off-screen is a small part of the image, almost as if the orthographic projection were messed up; but I've checked that, it's fine. So is the viewport. So it must be something else?> > ----- Original Message -----> From: Lindley M French <lfrench1@xxxxxxx>> Date: Wednesday, August 26, 2009 2:46 pm> Subject: [GtkGLExt] GdkGLPixmap troubles> > > I'm trying to allow an offscreen render to a pixmap to occur now, > > instead of trying to force an expose event while a window is > > offscreen like I was before.> > > > I've looked over the example code in pixmap.c that comes with > > GtkGLExt, but my adaptation of it isn't working.> > > > My configure-event handler:> > > > gboolean reshapeGL(GtkWidget *widget, GdkEventConfigure *evnt, > > gpointer data)> > {> > GUIWindow* me = (GUIWindow*)data;> > GdkGLContext *glcontext = gtk_widget_get_gl_context (widget);> > GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable (widget);> > > > assert(pthread_equal(me->mainthread, pthread_self()));> > fprintf(stderr,"reshaping window %d, %d %d %d %d\n",me-> > >window_id,evnt->x,evnt->y,evnt->width,evnt->height);> > > > if (!gdk_gl_drawable_gl_begin (gldrawable, glcontext))> > return FALSE;> > > > me->lock();> > me->xviewport = evnt->x;> > me->widthvp = evnt->width;> > me->yviewport = evnt->y;> > me->heightvp = evnt->height;> > glViewport(me->xviewport,me->yviewport,me->widthvp,me->heightvp);> > me->unlock();> > > > gdk_gl_drawable_gl_end (gldrawable);> > > > if (me->osPixmap)> > g_object_unref(me->osPixmap);> > if (me->osContext)> > gdk_gl_context_destroy(me->osContext);> > me->osPixmap = gdk_pixmap_new (widget->window,> > widget->allocation.width,> > widget->allocation.height,> > -1);> > GdkGLConfig *glconfig = gdk_gl_config_new_by_mode (> > GdkGLConfigMode(GDK_GL_MODE_RGB |> > GDK_GL_MODE_SINGLE));> > GdkGLDrawable *osDrawable = GDK_GL_DRAWABLE (> > gdk_pixmap_set_gl_capability (me->osPixmap,> > glconfig,> > NULL));> > me->osContext = gdk_gl_context_new (osDrawable,> > glcontext,> > FALSE,> > GDK_GL_RGBA_TYPE);> > > > return FALSE;> > }> > > > That all works fine so far as I can tell. There may be some issues > > with when exactly I'm supposed to unref something; the whole > > reference counting scheme is less than well-documented. However, > > I'm not concerned about that for now.> > > > I also have this function, which is not linked to any particular > > event:> > gboolean doTakeScreenshot(gpointer data)> > {> > GUIWindow *me = (GUIWindow *)data;> > > > assert(pthread_equal(me->mainthread, pthread_self()));> > > > me->lock();> > > > GdkGLDrawable *osDrawable = GDK_GL_DRAWABLE(me->osPixmap);> > if (!osDrawable || !me->osContext)> > {> > fprintf(stderr, "Warning, no offscreen pixbuf configured > > in aeGraphWindow::doTakeScreenshot.\n");> > me->signal(&me->screenshot_complete);> > me->unlock();> > return FALSE;> > }> > > > if (!gdk_gl_drawable_gl_begin (osDrawable, me->osContext))> > {> > me->signal(&me->screenshot_complete);> > me->unlock();> > return FALSE;> > }> > > > // OPENGL DRAWING HERE> > > > gdk_gl_drawable_wait_gl(osDrawable);> > glReadBuffer(GL_FRONT);> > glReadPixels(me->xviewport,me->yviewport,me->widthvp,me->heightvp,> > GL_RGBA,GL_UNSIGNED_BYTE,me->screenshot_dest-> > >data[0]);> > me->signal(&me->screenshot_complete);> > > > me->unlock();> > > > gdk_gl_drawable_gl_end (osDrawable);> > > > return FALSE;> > }> > > > It appears that gdk_gl_drawable_gl_begin() is failing here. What > > could cause that? Both the context and drawable being passed are > > valid pointers. However, I did notice that > > gdk_gl_context_get_gl_drawable(me->osContext) returned NULL, which > > I thought was odd.> > > > I'm not positive that my glReadPixels() is valid either, but I > > want to get past this hurdle before worrying about that one.> > > > Any ideas?> > _______________________________________________> > gtkglext-list mailing list> > gtkglext-list@xxxxxxxxx> > http://mail.gnome.org/mailman/listinfo/gtkglext-list> > > _______________________________________________> gtk-list mailing list> gtk-list@xxxxxxxxx> http://mail.gnome.org/mailman/listinfo/gtk-list> _______________________________________________gtk-list mailing listgtk-list@xxxxxxxxxxxxx://mail.gnome.org/mailman/listinfo/gtk-list
