pythia6_rng_callback.c.patch

--- /dev/null	2011-01-28 15:18:26.820752001 +0100
+++ pythia6_rng_callback.c	2011-02-03 21:35:13.542831166 +0100
@@ -0,0 +1,24 @@
+/* forward decl, original Pythia impl */
+extern double old_pyr_(int* idummy);
+
+/* function pointer contating the current impl */
+double (*pyr_callback)(int*) = 0;
+
+/* setter for the pyr callback */
+void set_pyr_callback(double (*new_callback)(int*) )
+{
+  pyr_callback = new_callback;
+}
+
+/* call the current PYR implementation */
+double ext_pyr_(int* idummy)
+{
+  if (pyr_callback)
+  {
+    return (*pyr_callback)(idummy);
+  }
+  else
+  {
+    return old_pyr_(idummy);
+  }
+}