Attached in a replacement for clutter_stage_glx_realize. It makes it possible to use Clutter with true per pixel alpha
and as OSD on top of another video window.
Jörn Reder wrote:
Emmanuele Bassi wrote:
if you provide a patch for the clutter-perl bindings to expose those
methods (under the Clutter::X11 namespace, for instance) and you verify
that they work, then I'll consider pushing it upstream.
[...]
what you need to do is create a small C library that implements a
subclass of ClutterStage and calls clutter_x11_stage_set_foreign()
inside the realize() virtual function -- after you chained up to the
parent implementation.
then write the Perl bindings using the perl-Glib machinery that
clutter-perl uses, and use the custom class inside your Perl code.
Thanks for your quick answer!
Since my C/glib knowledge is very limited (subclassing gobject's is
beyond my scope), I tried quick and dirty binding
clutter_x11_set_stage_foreign() in ClutterStage.xs to see if this is
basically working (using Clutter 0.820 from CPAN).
This is the xsub I added:
--snip--
gboolean
clutter_stage_set_foreign_x11_window(ClutterStage *stage, int xwindow)
CODE:
RETVAL = clutter_x11_set_stage_foreign(stage, (Window) xwindow);
OUTPUT:
RETVAL
--snip--
And used this small script to test:
--snip--
#!/usr/bin/perl
use strict;
use Gtk2 '-init';
use Clutter '-init';
use Glib qw(TRUE FALSE);
main: {
my $window = Gtk2::Window->new('toplevel');
$window->set_default_size(800, 400);
$window->set_decorated(0);
$window->signal_connect('delete_event', sub { Gtk2->main_quit; });
my $colormap = $window->get_screen->get_rgba_colormap;
$window->set_colormap($colormap) if $colormap;
$window->show_all;
my $xid = $window->window->get_xid;
print "xid=$xid\n";
my $stage = Clutter::Stage->get_default();
$stage->set_foreign_x11_window($xid);
$stage->set_color(Clutter::Color->parse('DarkBlue'));
$stage->set_opacity(128);
Gtk2->main;
}
--snip--
That gives me a warning:
(./osd-test-foreign.pl:20579): ClutterX11-WARNING **: Unable to retrieve the
new window geometry
and of course no active clutter stage at all ;)
The warning is issued by clutter-stage-x11.c on the check whether all
conditions of the target X11 window are met:
if (clutter_x11_untrap_x_errors () ||
!status ||
width == 0 || height == 0 ||
depth != stage_x11->xvisinfo->depth)
{
g_warning ("Unable to retrieve the new window geometry");
return FALSE;
}
I added some debugging output and found out that the depth condition is
the problem:
depth == 32
stage_x11->xvisinfo->depth == 24
So my X11 window has an alpha channel while the clutter stage has not.
Is this due to my "quick and dirty" approach or did I hit another
problem?
Thanks,
Jörn
static void
clutter_stage_glx_realize (ClutterActor *actor)
{
ClutterStageX11 *stage_x11 = CLUTTER_STAGE_X11 (actor);
ClutterStageGLX *stage_glx = CLUTTER_STAGE_GLX (actor);
ClutterBackendGLX *backend_glx;
ClutterBackendX11 *backend_x11;
gboolean is_offscreen;
CLUTTER_NOTE (MISC, "Realizing main stage");
g_object_get (stage_x11->wrapper, "offscreen", &is_offscreen, NULL);
backend_glx = CLUTTER_BACKEND_GLX (clutter_get_default_backend ());
backend_x11 = CLUTTER_BACKEND_X11 (clutter_get_default_backend ());
Colormap colormap = 0;
int eventBase, errorBase;
if (G_LIKELY (!is_offscreen))
{
int gl_attributes[] =
{
GLX_RGBA,
GLX_DOUBLEBUFFER,
GLX_RED_SIZE, 1,
GLX_GREEN_SIZE, 1,
GLX_BLUE_SIZE, 1,
GLX_STENCIL_SIZE, 1,
0
};
if (stage_x11->xvisinfo)
{
XFree (stage_x11->xvisinfo);
stage_x11->xvisinfo = None;
}
if (XRenderQueryExtension(stage_x11->xdpy, &eventBase, &errorBase)) {
int i, nvi;
XVisualInfo templ;
templ.screen = DefaultScreen(stage_x11->xdpy);
templ.depth = 32;
templ.class = TrueColor;
XVisualInfo *xvi = XGetVisualInfo(stage_x11->xdpy, VisualScreenMask |
VisualDepthMask | VisualClassMask, &templ, &nvi);
for (i = 0; i < nvi; ++i) {
XRenderPictFormat *format =
XRenderFindVisualFormat(stage_x11->xdpy, xvi[i].visual);
if (format->type == PictTypeDirect && format->direct.alphaMask) {
stage_x11->xvisinfo = g_memdup(&xvi[i], sizeof(Visual));
colormap = XCreateColormap(stage_x11->xdpy,
RootWindow(stage_x11->xdpy, DefaultScreen(stage_x11->xdpy)), xvi[i].visual,
AllocNone);
break;
}
}
}
/* The following check seems strange */
if (stage_x11->xvisinfo == None)
stage_x11->xvisinfo = glXChooseVisual (stage_x11->xdpy,
stage_x11->xscreen,
gl_attributes);
if (!stage_x11->xvisinfo)
{
g_critical ("Unable to find suitable GL visual.");
goto fail;
}
if (stage_x11->xwin == None)
{
XSetWindowAttributes xattr;
unsigned long mask;
CLUTTER_NOTE (MISC, "Creating stage X window");
/* window attributes */
xattr.background_pixel = WhitePixel (stage_x11->xdpy,
stage_x11->xscreen);
xattr.border_pixel = 0;
xattr.colormap = colormap ? colormap :
XCreateColormap (stage_x11->xdpy,
stage_x11->xwin_root,
stage_x11->xvisinfo->visual,
AllocNone);
mask = CWBorderPixel | CWColormap;
stage_x11->xwin = XCreateWindow (stage_x11->xdpy,
stage_x11->xwin_root,
0, 0,
stage_x11->xwin_width,
stage_x11->xwin_height,
0,
stage_x11->xvisinfo->depth,
InputOutput,
stage_x11->xvisinfo->visual,
mask, &xattr);
}
if (clutter_x11_has_event_retrieval())
{
if (clutter_x11_has_xinput())
{
XSelectInput (stage_x11->xdpy, stage_x11->xwin,
StructureNotifyMask |
FocusChangeMask |
ExposureMask |
KeyPressMask | KeyReleaseMask |
PropertyChangeMask);
#ifdef USE_XINPUT
_clutter_x11_select_events (stage_x11->xwin);
#endif
}
else
XSelectInput (stage_x11->xdpy, stage_x11->xwin,
StructureNotifyMask |
FocusChangeMask |
ExposureMask |
PointerMotionMask |
KeyPressMask | KeyReleaseMask |
ButtonPressMask | ButtonReleaseMask |
PropertyChangeMask);
}
/* no user resize.. */
clutter_stage_x11_fix_window_size (stage_x11);
clutter_stage_x11_set_wm_protocols (stage_x11);
if (G_UNLIKELY (backend_glx->gl_context == None))
{
CLUTTER_NOTE (GL, "Creating GL Context");
backend_glx->gl_context = glXCreateContext (stage_x11->xdpy,
stage_x11->xvisinfo,
0,
True);
if (backend_glx->gl_context == None)
{
g_critical ("Unable to create suitable GL context.");
goto fail;
}
}
CLUTTER_NOTE (BACKEND, "Marking stage as realized");
CLUTTER_ACTOR_SET_FLAGS (stage_x11, CLUTTER_ACTOR_REALIZED);
}
else
{
int gl_attributes[] = {
GLX_DEPTH_SIZE, 0,
GLX_ALPHA_SIZE, 0,
GLX_RED_SIZE, 1,
GLX_GREEN_SIZE, 1,
GLX_BLUE_SIZE, 1,
GLX_USE_GL,
GLX_RGBA,
0
};
if (stage_x11->xvisinfo)
XFree (stage_x11->xvisinfo);
stage_x11->xvisinfo = NULL;
CLUTTER_NOTE (GL, "glXChooseVisual");
stage_x11->xvisinfo = glXChooseVisual (stage_x11->xdpy,
stage_x11->xscreen,
gl_attributes);
if (!stage_x11->xvisinfo)
{
g_critical ("Unable to find suitable GL visual.");
goto fail;
}
stage_x11->xpixmap = XCreatePixmap (stage_x11->xdpy,
stage_x11->xwin_root,
stage_x11->xwin_width,
stage_x11->xwin_height,
DefaultDepth (stage_x11->xdpy,
stage_x11->xscreen));
stage_glx->glxpixmap = glXCreateGLXPixmap (stage_x11->xdpy,
stage_x11->xvisinfo,
stage_x11->xpixmap);
if (backend_glx->gl_context == None)
{
CLUTTER_NOTE (GL, "Creating GL Context");
/* FIXME: we probably need a seperate offscreen context here
* - though it likely makes most sense to drop offscreen stages
* and rely on FBO's instead and GLXPixmaps seems mostly broken
* anyway..
*/
backend_glx->gl_context = glXCreateContext (stage_x11->xdpy,
stage_x11->xvisinfo,
0,
False);
if (backend_glx->gl_context == None)
{
g_critical ("Unable to create suitable GL context.");
goto fail;
}
}
CLUTTER_NOTE (BACKEND, "Marking stage as realized");
CLUTTER_ACTOR_SET_FLAGS (stage_x11, CLUTTER_ACTOR_REALIZED);
}
/* we need to chain up to the X11 stage implementation in order to
* set the window state in case we set it before realizing the stage
*/
CLUTTER_ACTOR_CLASS (clutter_stage_glx_parent_class)->realize (actor);
return;
fail:
CLUTTER_ACTOR_UNSET_FLAGS (actor, CLUTTER_ACTOR_REALIZED);
}
