+(define view-meshes-set! (record-modifier view-type 'meshes))
+(define view-controllers (record-accessor view-type 'controllers))
+(define view-controllers-set! (record-modifier view-type 'controllers))
+(define view-priority (record-accessor view-type 'priority))
+
+(defmacro* view (#:key (priority 0) . elements)
+ `(let ((e (view-elements ,@elements)))
+ (make-view (car e) (cadr e) ,priority)))
+
+(define-macro (view-elements . elements)
+ (cond ((null? elements) `'(() ()))
+ (else
+ `(let ((l (view-elements ,@(cdr elements))))
+ ,(let ((e (car elements)))
+ `(cond ((mesh? ,e)
+ (list (car l) (cons ,e (cadr l))))
+ ((procedure? ,e)
+ (list (cons ,(if (list? e) e `(lambda () (,e))) (car l))
+ (cadr l)))
+ (else l)))))))
+
+(define (controllers-list list controllers)
+ (cond ((null? controllers)
+ list)
+ ((list? (car controllers))
+ (assoc-set! (controllers-list list (cdr controllers)) (caar controllers) (cadar controllers)))
+ (else
+ (assoc-set! (controllers-list list (cdr controllers)) (gensym) (car controllers)))))
+
+(define activated-views '())
+
+(define (sort-views views-alist)
+ (sort views-alist
+ (lambda (v1 v2)
+ (< (view-priority (cdr v1)) (view-priority (cdr v2))))))
+
+(define (activate-view view)
+ (set! activated-views
+ (sort-views (assoc-set! activated-views (view-id view) view)))
+ view)
+
+(define (view-actived? view)
+ (and (assoc (view-id view) activated-views) #t))