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>

2 files changed, 36 insertions, 1 deletions

diff --git a/boilerplate/cairo-boilerplate-xcb.c b/boilerplate/cairo-boilerplate-xcb.c
index c5dee8ee9..d4c70be67 100644
--- a/boilerplate/cairo-boilerplate-xcb.c
+++ b/boilerplate/cairo-boilerplate-xcb.c
@@ -86,6 +86,17 @@ _cairo_boilerplate_xcb_sync_server (xcb_target_closure_t *xtc)
 }
 
 static void
+_cairo_boilerplate_xcb_setup_test_surface (cairo_surface_t *surface)
+{
+
+    /* For testing purposes, tell the X server to strictly adhere to the
+     * Render specification.
+     */
+    cairo_xcb_device_debug_set_precision(cairo_surface_get_device(surface),
+					 PolyModePrecise);
+}
+
+static void
 _cairo_boilerplate_xcb_cleanup (void *closure)
 {
     xcb_target_closure_t *xtc = closure;
@@ -241,6 +252,9 @@ _cairo_boilerplate_xcb_create_surface (const char		 *name,
 							    width, height);
     free (formats);
 
+    if (mode != CAIRO_BOILERPLATE_MODE_PERF)
+	cairo_xcb_surface_setup_test_surface(surface);
+
     xtc->device = cairo_device_reference (cairo_surface_get_device (surface));
     status = cairo_surface_set_user_data (surface, &xcb_closure_key, xtc, NULL);
     if (status == CAIRO_STATUS_SUCCESS)
diff --git a/boilerplate/cairo-boilerplate-xlib.c b/boilerplate/cairo-boilerplate-xlib.c
index fbc999078..f82b78b8d 100644
--- a/boilerplate/cairo-boilerplate-xlib.c
+++ b/boilerplate/cairo-boilerplate-xlib.c
@@ -78,6 +78,18 @@ _cairo_boilerplate_xlib_check_screen_size (Display *dpy,
     return width <= WidthOfScreen (scr) && height <= HeightOfScreen (scr);
 }
 
+static void
+_cairo_boilerplate_xlib_setup_test_surface (cairo_surface_t *surface)
+{
+
+    /* For testing purposes, tell the X server to strictly adhere to the
+     * Render specification.
+     */
+    cairo_xlib_device_debug_set_precision(cairo_surface_get_device(surface),
+					  PolyModePrecise);
+}
+
+
 #if CAIRO_HAS_XLIB_XRENDER_SURFACE
 /* For the xlib backend we distinguish between TEST and PERF mode in a
  * couple of ways.
@@ -98,6 +110,7 @@ _cairo_boilerplate_xlib_test_create_surface (Display		   *dpy,
 					     xlib_target_closure_t *xtc)
 {
     XRenderPictFormat *xrender_format;
+    cairo_surface_t *surface;
 
     /* This kills performance, but it makes debugging much
      * easier. That's why we have it here when in TEST mode, but not
@@ -133,10 +146,14 @@ _cairo_boilerplate_xlib_test_create_surface (Display		   *dpy,
 				   width, height, xrender_format->depth);
     xtc->drawable_is_pixmap = TRUE;
 
-    return cairo_xlib_surface_create_with_xrender_format (dpy, xtc->drawable,
+    surface = cairo_xlib_surface_create_with_xrender_format (dpy, xtc->drawable,
 							  DefaultScreenOfDisplay (dpy),
 							  xrender_format,
 							  width, height);
+
+    _cairo_boilerplate_xlib_setup_test_surface(surface);
+
+    return surface;
 }
 
 static cairo_surface_t *
@@ -333,6 +350,8 @@ _cairo_boilerplate_xlib_window_create_surface (const char		 *name,
     if (cairo_surface_status (surface))
 	_cairo_boilerplate_xlib_cleanup (xtc);
 
+    _cairo_boilerplate_xlib_setup_test_surface(surface);
+
     return surface;
 }
 
@@ -477,6 +496,8 @@ _cairo_boilerplate_xlib_fallback_create_surface (const char		   *name,
     else
 	cairo_boilerplate_xlib_surface_disable_render (surface);
 
+    _cairo_boilerplate_xlib_setup_test_surface(surface);
+
     return surface;
 }
 #endif