;; --- CSU213 Fall 2006 Lecture Notes ---------
;; Copyright 2006 Viera K. Proulx

;; Lecture 3: September 11, 2006
;; Part 1: Playing Calder

;; Building Mobiles
;; ----------------

;; A Mobile Construction is (make-mobilething Posn Mobile)
(define-struct mobilething (origin mobile))

;; A Mobile-Construction is (make-mobile Posn Mobile)
(define-struct mconstruction (origin mobile))

;; A Mobile is one of
;; --- (make-mend Number Number Color)
;; --- (make-mstrut Number Number Mobile Number Mobile)

(define-struct mend (length weight color))
(define-struct mstrut (length loffset lmobile roffst rmobile))

;; Examples:

(define redmobile (make-mend 10 6 "red"))
(define greenmobile (make-mend 10 4 "green"))
(define bluemobile (make-mend 40 10 "blue"))

(define leftmobile (make-mstrut 30 40 redmobile 20 greenmobile))
(define mymobile (make-mstrut 20 50 leftmobile 30 bluemobile))

(define themobile (make-mconstruction (make-posn 120 20) mymobile))