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, 4 insertions, 0 deletions

diff --git a/src/cairo-spans.c b/src/cairo-spans.c
index af3b85ff4..7067a5eb6 100644
--- a/src/cairo-spans.c
+++ b/src/cairo-spans.c
@@ -266,6 +266,8 @@ _cairo_scan_converter_create_in_error (cairo_status_t status)
     case CAIRO_STATUS_NO_MEMORY: RETURN_NIL;
     case CAIRO_STATUS_INVALID_SIZE: RETURN_NIL;
     case CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED: RETURN_NIL;
+    case CAIRO_STATUS_DEVICE_TYPE_MISMATCH: RETURN_NIL;
+    case CAIRO_STATUS_DEVICE_ERROR: RETURN_NIL;
     default:
 	break;
     }
@@ -372,6 +374,8 @@ _cairo_span_renderer_create_in_error (cairo_status_t status)
     case CAIRO_STATUS_NO_MEMORY: RETURN_NIL;
     case CAIRO_STATUS_INVALID_SIZE: RETURN_NIL;
     case CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED: RETURN_NIL;
+    case CAIRO_STATUS_DEVICE_TYPE_MISMATCH: RETURN_NIL;
+    case CAIRO_STATUS_DEVICE_ERROR: RETURN_NIL;
     default:
 	break;
     }