(clear)
(define v (vector 0 0 0))
(define i (vector 0 0 0))
(define t (vector 0 0 0))
(define points '())
(gain 0.1)
(clear-colour (vector 0 0 1))

;(hint-none)
(hint-unlit)
;(hint-wire)
;(line-width 4)
;(texture (load-texture "grad.png"))
(define ob (build-nurbs-sphere 5 7))

; reads the points into a list
(define (store n)
    (set! points (cons (pdata-get "p" n) points))
    (if (< n 0)
        0
        (store (- n 1))))

(define (deform n p)
    (set! v (vector (* 0.4 (sin (+ (time) (*(vector-ref (car p) 1) 10.4)))) 0 0))
    (set! v (vmul v (* (gh n) 0.1)))
    (pdata-set "p" n (vadd v (car p)))
    (if (< n 0)
        0
        (deform (- n 1) (cdr p))))    
    
(define (toon n camerapos obpos)
    (set! v (vadd obpos (pdata-get "p" n))) ; vertex in worldspace 
    (set! i (vnormalise (vsub v camerapos))) ; incident direction    
    (pdata-set "t" n (vector (vdot i (pdata-get "n" n)) 0 0)) ; set s to the facing ratio    
    (if (< n 0)
        0
        (toon (- n 1) camerapos obpos)))    

(define (render)
    (grab ob)
    (deform (pdata-size) points)
    (recalc-normals)
    (toon (pdata-size)
        (vtransform (vector 0 0 0) (get-camera-transform))
        (vtransform (vector 0 0 0) (get-transform)))
    (ungrab)

    ;(render-instances 1)
)

(define (render-instances n)
    (translate (vector 1 0 0))
    (draw-instance ob)
    (if (< n 0)
        0
        (render-instances (- n 1))))

(grab ob)
(store (pdata-size))
(ungrab)

(every-frame "(render)")