ps (debug API): Export the ability to force fallbacks

We need to occasionally force fallbacks whilst testing the PostScript
output, so export a debug interface to do so in order to avoid poking
around inside cairo internals.

References: https://bugs.freedesktop.org/show_bug.cgi?id=48577
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

boilerplate/cairo-boilerplate-ps.c

@@ -30,9 +30,6 @@
 
 #include <cairo-ps.h>
 
-#include <cairo-ps-surface-private.h>
-#include <cairo-paginated-surface-private.h>
-
 #if HAVE_SIGNAL_H
 #include <signal.h>
 #endif
@@ -265,23 +262,18 @@ _cairo_boilerplate_ps_cleanup (void *closure)
 }
 
 static void
-_cairo_boilerplate_ps_force_fallbacks (cairo_surface_t *abstract_surface,
+_cairo_boilerplate_ps_force_fallbacks (cairo_surface_t *surface,
 				       double		 x_pixels_per_inch,
 				       double		 y_pixels_per_inch)
 {
-    ps_target_closure_t *ptc = cairo_surface_get_user_data (abstract_surface,
-							    &ps_closure_key);
-
-    cairo_paginated_surface_t *paginated;
-    cairo_ps_surface_t *surface;
+    ps_target_closure_t *ptc =
+	cairo_surface_get_user_data (surface, &ps_closure_key);
 
     if (ptc->target)
-	abstract_surface = ptc->target;
+	surface = ptc->target;
 
-    paginated = (cairo_paginated_surface_t*) abstract_surface;
-    surface = (cairo_ps_surface_t*) paginated->target;
-    surface->force_fallbacks = TRUE;
-    cairo_surface_set_fallback_resolution (&paginated->base,
+    cairo_ps_surface_debug_force_fallbacks (surface);
+    cairo_surface_set_fallback_resolution (surface,
 					   x_pixels_per_inch,
 					   y_pixels_per_inch);
 }

src/cairo-ps-surface.c

@@ -1385,6 +1385,27 @@ cairo_ps_surface_debug_set_creation_date (cairo_surface_t *abstract_surface,
     surface->creation_date = date;
 }
 
+/**
+ * cairo_ps_surface_debug_force_fallbacks:
+ * @surface: a PostScript #cairo_surface_t
+ *
+ * This is purely a debugging interface, intended only to be used in
+ * conformation testing, to force the surface to contain only rasterised
+ * graphics and no native PostScript drawing.
+ *
+ * Since: 1.12.2
+ **/
+void
+cairo_ps_surface_debug_force_fallbacks (cairo_surface_t *abstract_surface)
+{
+    cairo_ps_surface_t *surface = NULL;
+
+    if (! _extract_ps_surface (abstract_surface, TRUE, &surface))
+	return;
+
+    surface->force_fallbacks = TRUE;
+}
+
 /**
  * cairo_ps_surface_dsc_comment:
  * @surface: a PostScript #cairo_surface_t

src/cairo-ps.h

@@ -114,6 +114,9 @@ cairo_public void
 cairo_ps_surface_debug_set_creation_date (cairo_surface_t *abstract_surface,
 					  time_t	  date);
 
+cairo_public void
+cairo_ps_surface_debug_force_fallbacks (cairo_surface_t *abstract_surface);
+
 CAIRO_END_DECLS
 
 #else  /* CAIRO_HAS_PS_SURFACE */