; an example of the fluxus extrusion tool

(require scheme/class)

(define min-fin-len 3)
(define fin-length-var 6)
(define fin-grow-prob 2)
(define max-fins-per-twig 5)


(define fin%
    (class object%
        (init-field
            (fin-size 1)
            (twig-ob #f)
            (col (vector 0 0 0))
            (path-len 0)
            (profile-len 0))
        
        (field
            (fin-len (min path-len (+ min-fin-len (random fin-length-var))))
            (root (build-polygons (* fin-len 2) 'triangle-strip))
            (pos (random profile-len))
            (start (* (random (- path-len fin-len)) profile-len))
            (grow-t 0)
            (grow-speed (* (rndf) 0.1)))
        
        (define/public (build)
            (with-primitive root
                (parent twig-ob)
                (texture (load-texture "textures/fin-roots.png"))
                (hint-unlit)
                (hint-depth-sort)
                (colour col)
                (backfacecull 0)
                (pdata-index-map!
                    (lambda (i t)
                        (vector (/ (+ (quotient i 2) 1) (/ (pdata-size) 2)) (if (odd? i) 1 0) 0))
                    "t")))
        
        (define/public (update t d)
            (when (< grow-t 1)
            (with-primitive root
                (pdata-index-map!            
                    (lambda (i p)            
                        (let* ((ti (+ start pos (* (quotient i 2) profile-len)))
                                (tp (with-primitive twig-ob (pdata-ref "p" ti)))
                                (tn (with-primitive twig-ob (pdata-ref "n" ti))))
                            (if (even? i)
                                tp
                                (vadd tp (vmul tn (* grow-t fin-size))))))
                    "p"))
            
            (set! grow-t (+ grow-t (* d grow-speed)))))
        
        (super-new)))

(clear)
(clear-colour 0.5)
(define profile (build-circle-profile 12 0.5))

(define width (build-list 20
        (lambda (n) (* n 0.01 (+ 1.5 (cos (* 0.5 n)))))))

(define path (build-list 20
        (lambda (n) (vadd (vector 1 0 0) (vmul (vector (sin (* 0.2 n)) 0 (cos (* 0.2 n))) (* 0.05 n))))))

(define p (with-state
        (wire-colour 0)
        (colour (vector 1 1 1))   
        (specular (vector 1 1 1))
        (shinyness 20)
        (hint-wire)
        ;        (hint-normal)
        (build-extrusion profile path width 10 (vector 0 1 0))))

(define fins (build-list 10
    (lambda (_)
        (let ((f (make-object fin% 0.5 p (vector 1 1 1) (length path) (length profile))))
            (send f build)
            f))))

(every-frame (for-each
        (lambda (f)
             (send f update (time) (delta)))
        fins))
        

#;(define (animate)
    (with-primitive p
        (partial-extrude 
            (* (* 0.5 (+ 1 (sin (* 1 (time))))) (+ (length path) 5)) 
            profile path width (vector 0 1 0) 0.05)))

#;(every-frame (animate))