xlib,xcb: Force strict adherence to the Render specification when testing

Introduce cairo_xlib_device_debug_set_precision() to override the
automatic selection of rendering precision and force the Xorg/DDX to
strictly adhere to the precise rendering mode of the Render
specification. This allows us to test drivers without worrying, too
much, about minor discrepancies in antialiasing.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/cairo-xlib.h b/src/cairo-xlib.h
index 4ee592ce..7f770b97 100644
--- a/src/cairo-xlib.h
+++ b/src/cairo-xlib.h
@@ -91,6 +91,19 @@ cairo_xlib_surface_get_width (cairo_surface_t *surface);
 cairo_public int
 cairo_xlib_surface_get_height (cairo_surface_t *surface);
 
+/* debug interface */
+
+/*
+ * @precision: -1 implies automatically choose based on antialiasing mode,
+ *            any other value overrides and sets the corresponding PolyMode.
+ */
+cairo_public void
+cairo_xlib_device_debug_set_precision (cairo_device_t *device,
+				       int precision);
+
+cairo_public int
+cairo_xlib_device_debug_get_precision (cairo_device_t *device);
+
 CAIRO_END_DECLS
 
 #else  /* CAIRO_HAS_XLIB_SURFACE */