Set engine systems while running

[gacela.git] / src / system.scm

diff --git a/src/system.scm b/src/system.scm
index 3d5cb2b9ea482eaaaf65a81946e337d693cd94bb..2bf05208fefb215eec76c28e3075ce0a3f56e218 100644 (file)
--- a/src/system.scm
+++ b/src/system.scm
@@ -247,11 +247,20 @@
             (receive (e2 c2) ((join-thread (car thd)) e c)
               (run-wait (cdr thd) e2 c2)))))))
 
+(define (group-systems . systems)
+  (cond ((null? systems)
+        (make-system ()))
+       ((= (length systems) 1)
+        (car systems))
+       (else
+        (join-systems systems))))
+
 (export find-entities-by-components
        define-system
        make-system
        join-systems
-       threaded-systems)
+       threaded-systems
+       group-systems)
 
 
 ;;; Entities and components access inside systems