Add cairo_device_t

The device is a generic method for accessing the underlying interface
with the native graphics subsystem, typically the X connection or
perhaps the GL context. By exposing a cairo_device_t on a surface and
its various methods we enable finer control over interoperability with
external interactions of the device by applications. The use case in
mind is, for example, a multi-threaded gstreamer which needs to serialise
its own direct access to the device along with Cairo's across many
threads.

Secondly, the cairo_device_t is a unifying API for the mismash of
backend specific methods for controlling creation of surfaces with
explicit devices and a convenient hook for debugging and introspection.

The principal components of the API are the memory management of:

  cairo_device_reference(),
  cairo_device_finish() and
  cairo_device_destroy();

along with a pair of routines for serialising interaction:

  cairo_device_acquire() and
  cairo_device_release()

and a method to flush any outstanding accesses:

  cairo_device_flush().

The device for a particular surface may be retrieved using:

  cairo_surface_get_device().

The device returned is owned by the surface.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/cairo-directfb-surface.c b/src/cairo-directfb-surface.c
index 0d39e4b5b..e3ee36608 100644
--- a/src/cairo-directfb-surface.c
+++ b/src/cairo-directfb-surface.c
@@ -565,6 +565,7 @@ _cairo_directfb_surface_create_internal (IDirectFB *dfb,
 
     _cairo_surface_init (&surface->base,
 			 &_cairo_directfb_surface_backend,
+			 NULL, /* device */
 			 content);
     surface->pixman_format = _directfb_to_pixman_format (format);
     surface->supported_destination = pixman_format_supported_destination (surface->pixman_format);
@@ -1956,6 +1957,7 @@ cairo_directfb_surface_create (IDirectFB *dfb, IDirectFBSurface *dfbsurface)
 
     _cairo_surface_init (&surface->base,
                          &_cairo_directfb_surface_backend,
+			 NULL, /* device */
 			 _directfb_format_to_content (format));
 
     return &surface->base;