cairoSurfaceWriteToPngStream(surface, con)
surface
CairoSurface
] a CairoSurface
with pixel contentsCairoStatus
] CAIRO_STATUS_SUCCESS if the PNG file was written
successfully. Otherwise, CAIRO_STATUS_NO_MEMORY is returned if
memory could not be allocated for the operation,
CAIRO_STATUS_SURFACE_TYPE_MISMATCH if the surface does not have
pixel contents.