On Tue, 12 May 2015 10:47:08 +0300 Pekka Paalanen <ppaala...@gmail.com> wrote:
> On Mon, 11 May 2015 16:07:26 +0100 > Daniel Stone <dan...@fooishbar.org> wrote: > > > Hi, > > > > On 11 May 2015 at 13:41, Pekka Paalanen <ppaala...@gmail.com> wrote: > > > Did you notice, that 'clientside-screenshot.png' ends up all black, if > > > you do 'make check BACKEND=x11-backend.so'? > > > Wonder why it does that, you're not intending to do anything > > > backend-specific. Except the server command line arguments? > > > > €10 says this is only on uncomposited X11 servers, where you require > > Expose events ... ? > > I find that hard to believe... > > x11_output_repaint_shm() -> > pixman_renderer_repaint_output() does a repaint to the shadow, then > copy_to_hw_buffer() and just before returning it emits the > output->frame_signal. > > Output->frame_signal should lead to a call to > weston_renderer::read_pixels, which reads from the hw_buffer, which is > only a pixman_image_t... > > So all of rendering and read_pixels should be already done when control > returns to x11_output_repaint_shm(), so there is no room for X11 calls > in between. > > The hw_surface (hw_buffer) is created by pixman_image_create_bits() > which is handed a pointer to a piece of memory from shmat(). > > Looks like screenshooting does not go through X11 protocol, so I'm > puzzled why it doesn't seem to work. Also, the screenshooter (super+s) > works just fine. Seems to be a fun race somehow. If I add a sleep(1) in the test client just before it asks the server to take a screenshot, the saved image turns up fine instead of black. Oh I know. The test runs before weston-desktop-shell has initialized. That means there is no background to be shot yet. I do not think adding the necessary infrastructure to wait for weston-desktop-shell to come up is necessary at this point (it might be useful later in more advanced tests). What you could do is have the test client post a surface with know position and a known test pattern as the content. That can reliably be expected to work. The test still fails though, even if the captured image seems ok: Loading reference image /home/pq/git/weston/tests/reference/internal-screenshot-00.png Screenshot different from reference image Clip: 50,50 20 x 20 Bytewise comparison inside clip Mismatched image on row 50 50,0: e e 50,1: ffffffff ffffffff 50,2: 29 29 50,3: 1b 1b 50,4: e e 50,5: ffffffff ffffffff 50,6: 29 29 50,7: 1b 1b 50,8: e e 50,9: ffffffff ffffffff 50,10: 29 ffffffb2 <--- 50,11: 1b ffffffae <--- 50,12: e ffffffa9 <--- 50,13: ffffffff ffffffff 50,14: 29 ffffffa2 <--- 50,15: 1b ffffffa0 <--- 50,16: e ffffff9e <--- 50,17: ffffffff ffffffff 50,18: 29 10 <--- 50,19: 1b a <--- Screenshot doesn't match reference image in clipped area My guess is the comparison fails due to bugs in bpp/stride handling etc. The saved PNG files look identical apart from the date in the panel. Thanks, pq _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel
