MovingCubes

From MHCGraphics

; Mead example file - moving cubes!
; This demonstrates the ability to get handles on Mead objects
; at various times, and how to use them to animate objects
;
; Jim Teresco
; Computer Science 110
; Mount Holyoke College
;
; $Id: MovingCubes.scm 624 2008-04-13 21:01:46Z terescoj $
;
(require (lib "Defs.ss" "Mead"))

(tell image
      (background white)
      (fileName "MovingCubes")
      (frameNumber 0)
      (viewResult #f)
      )

; let's add some cubes, some using the default Cube, which we know
; is defined by Mead as:
; (object cube Cube)
; and some we define to have a different size
(object myCube Cube
        (scale .5 .5 .5))

(define c1
  (tell scene
        (add cube redPlaster
             (translate -100 100 0)
             )
        )
  )
(define c2
  (tell scene
        (add cube bluePlaster
             (translate -100 -100 0)
             )
        )
  )
(define c3
  (tell scene
        (add myCube greenPlaster
             (translate 100 100 0)
             )
        )
  )
(define c4
  (tell scene
        (add myCube magentaPlaster
             (translate 100 -100 0)
             )
        )
  )

; define a movement function for our cubes
(define (moveCubes whichCube pos scaling yRotVal)
  (tell whichCube
        (absoluteXform
         (compose
          (yRot yRotVal)
          (scale scaling scaling scaling)
          (translate (car pos)(cadr pos)(caddr pos))
          )
         )
        )
  )

; another movement function
(define (relativeScaleCubes whichCube scaling)
  ; this one is a relativeXform, so it scales "in place"
  (tell whichCube
        (scale scaling scaling scaling)
        )
  )

(define (absoluteScaleCubes whichCube scaling)
  ; this one is a relativeXform, so it scales "in place"
  (tell whichCube
        (absoluteXform
         (scale scaling scaling scaling)
         )
        )
  )

; lots of possibilities for animations:
; try each to see what happens and understand why
(tell camera
      ;(film 30 moveCubes c1 '((-100 100 0)) 1 '(0 90))
      ;(film 30 moveCubes c2 '((-100 -100 0)) 1 '(0 90))
      ;(film 30 moveCubes c3 '((100 100 0)) 1 '(0 90))
      ;(film 30 moveCubes c4 '((100 -100 0)) 1 '(0 90))
      ;(film 30 relativeScaleCubes cube .9)
      ;(film 30 absoluteScaleCubes cube '(1 .1 1))
      ;(film 30 relativeScaleCubes myCube .9)
      ;(film 30 absoluteScaleCubes myCube '(1 .1 1))
      (film 30 relativeScaleCubes c3 .9)
      ;(film 30 absoluteScaleCubes c3 '(1 .1 1))
      (buildMovie)
      )