Specifies the callbacks used to generate the image surface for a rendering
operation (acquire) and the function used to cleanup that surface afterwards.
The acquire callback should create a surface (preferably an image
surface created to match the target using
cairo_surface_create_similar_image()) that defines at least the region
of interest specified by extents. The surface is allowed to be the entire
sample area, but if it does contain a subsection of the sample area,
the surface extents should be provided by setting the device offset (along
with its width and height) using cairo_surface_set_device_offset().
Since 1.12
Specifies the callbacks used to generate the image surface for a rendering operation (acquire) and the function used to cleanup that surface afterwards. The acquire callback should create a surface (preferably an image surface created to match the target using cairo_surface_create_similar_image()) that defines at least the region of interest specified by extents. The surface is allowed to be the entire sample area, but if it does contain a subsection of the sample area, the surface extents should be provided by setting the device offset (along with its width and height) using cairo_surface_set_device_offset(). Since 1.12