Track swap interval in QXcbWindow

As per GLX_EXT_swap_control, the GLX swap interval is specified on a
per-drawable basis. However, QGLXContext only tracks it per-context
using the m_swapInterval member. If a new drawable is made current to a
context, it is still necessary to call glXSwapIntervalEXT to change the
swap interval, even if it has been previously called for the same
context with a different drawable.  However, currently,
QGLXContext::makeCurrent doesn't do this if its m_swapInterval field
matches the new swap interval. This change removes m_swapInterval from
QGLXContext, instead tracking it in QXcbWindow. This still avoids
unnecessary calls to glXSwapIntervalEXT, while ensuring the swap
interval is always set for new window drawables.

Change-Id: Idc34101476c6af618059f6f3d8925dee743994a3
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
 

1 files changed, 0 insertions, 1 deletions

diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.h b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.h
index be9d3f5dcb..2a88fd6e59 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.h
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.h
@@ -87,7 +87,6 @@ private:
     GLXContext m_shareContext;
     QSurfaceFormat m_format;
     bool m_isPBufferCurrent;
-    int m_swapInterval;
     bool m_ownsContext;
     GLenum (APIENTRY * m_getGraphicsResetStatus)();
     bool m_lost;