groworld/plant-eyes/extrude.scm

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2009-06-25 10:18:37 +00:00
(define (draw-profile index profile offset)
(cond ((not (null? profile))
(pdata-set! "p" index (vadd (car profile) offset))
(draw-profile (+ index 1) (cdr profile) offset))))
(define (transform-profile profile m)
(cond
((null? profile) '())
(else
(cons (vtransform (car profile) m)
(transform-profile (cdr profile) m)))))
; figures out the vector for rotation of the profile
(define (path-vector first-segment path lv)
(let* ((v (if (null? (cdr path)) ; last segment?
lv ; use the last vector used
(vsub (cadr path) (car path)))) ; use the next point
(vd (if first-segment v ; first segment?
(vadd (vmul lv 0.5) ; blend with the last vector
(vmul v 0.5)))))
vd))
(define (extrude-segment index profile path lv)
(cond ((not (null? path))
(let ((v (path-vector (zero? index) path lv)))
(draw-profile index (transform-profile profile
(mmul
(maim v (vector 0 1 0))
(mrotate (vector 0 90 0))))
(car path))
v))))
(define (mmix a b t)
(vector
(+ (* (vector-ref a 0) (- 1 t)) (* (vector-ref b 0) t))
(+ (* (vector-ref a 1) (- 1 t)) (* (vector-ref b 1) t))
(+ (* (vector-ref a 2) (- 1 t)) (* (vector-ref b 2) t))
(+ (* (vector-ref a 3) (- 1 t)) (* (vector-ref b 3) t))
(+ (* (vector-ref a 4) (- 1 t)) (* (vector-ref b 4) t))
(+ (* (vector-ref a 5) (- 1 t)) (* (vector-ref b 5) t))
(+ (* (vector-ref a 6) (- 1 t)) (* (vector-ref b 6) t))
(+ (* (vector-ref a 7) (- 1 t)) (* (vector-ref b 7) t))
(+ (* (vector-ref a 8) (- 1 t)) (* (vector-ref b 8) t))
(+ (* (vector-ref a 9) (- 1 t)) (* (vector-ref b 9) t))
(+ (* (vector-ref a 10) (- 1 t)) (* (vector-ref b 10) t))
(+ (* (vector-ref a 11) (- 1 t)) (* (vector-ref b 11) t))
(+ (* (vector-ref a 12) (- 1 t)) (* (vector-ref b 12) t))
(+ (* (vector-ref a 13) (- 1 t)) (* (vector-ref b 13) t))
(+ (* (vector-ref a 14) (- 1 t)) (* (vector-ref b 14) t))
(+ (* (vector-ref a 15) (- 1 t)) (* (vector-ref b 15) t))))
(define (extrude-segment-blend index profile path lv t)
(cond ((not (null? path))
; figure out the vector for rotation of the profile
(let ((v (path-vector (zero? index) path v)))
(cond ((null? (cdr path))
(draw-profile index (transform-profile profile
(mmul
(maim v (vector 0 1 0))
(mrotate (vector 0 90 0))))
(car path)))
(else
(let ((v2 (path-vector (zero? index) (cdr path) v)))
(draw-profile index (transform-profile profile
(mmul
(maim (vmix (vnormalise v) (vnormalise v2) t) (vector 0 1 0))
(mrotate (vector 0 90 0))))
(vmix (car path) (vadd (car path) v2) t)))))
v))))
(define (extrude index profile path lv)
(cond ((not (null? path))
(let ((v (extrude-segment index profile path lv)))
(extrude (+ index (length profile)) profile (cdr path) v)))))
(define (stitch-face index count profile-size in)
(cond
((eq? 1 count)
(append in (list (+ (- index profile-size) 1) index (+ index profile-size)
(+ (- index profile-size) 1 profile-size))))
(else
(append
(list (+ index 1) index
(+ index profile-size) (+ index profile-size 1))
(stitch-face (+ index 1) (- count 1) profile-size in)))))
(define (stitch-indices index profile-size path-size in)
(cond
((eq? 1 path-size) in)
(else
(append
(stitch-face index profile-size profile-size '())
(stitch-indices (+ index profile-size)
profile-size
(- path-size 1)
in)))))
(define (build-extrusion profile path)
(let ((p (build-polygons (* (length profile) (length path)) 'quad-list)))
(with-primitive p
(poly-set-index (stitch-indices 0 (length profile) (length path) '()))
(extrude 0 profile path (vector 0 0 0))
(recalc-normals 0))
p))
; partial extrusions are for animating
(define (build-partial-extrusion profile path)
(let ((p (build-polygons (* (length profile) (length path)) 'quad-list)))
(with-primitive p
(poly-set-index (stitch-indices 0 (length profile) (length path) '())))
p))
(define (chop-front l n)
(cond ((null? l) l)
(else
(if (zero? n) (cons (car l) (chop-front (cdr l) n))
(chop-front (cdr l) (- n 1))))))
; returns the last vector
(define (partial-extrude p t v profile path)
(with-primitive p 0
(let* ((start (* (floor t) (length profile)))
(end (* (length path) (length profile)))
(v (extrude-segment start profile
(chop-front path (floor t)) v)))
(when (< t (- (length path) 1))
(for ((i (in-range (+ start (length profile)) (+ start (* 2 (length profile))))))
(pdata-set! "p" i (vsub (pdata-ref "p" (- i (length profile)))
(vmul v (- (floor t) t)))))
; collapse the yet un-extruded part into the last vert
(for ((i (in-range (+ start (* (length profile) 2)) end)))
(pdata-set! "p" i (pdata-get "p" (+ (length profile) start)))))
(recalc-normals 0)
v)))
#;(define (partial-extrude p t v profile path)
(with-primitive p 0
(let* ((start (* (floor t) (length profile)))
(end (* (length path) (length profile)))
(v (extrude-segment-blend start profile
(chop-front path (floor t)) v (- (floor t) t))))
(when (< t (- (length path) 1))
#;(for ((i (in-range (+ start (length profile)) (+ start (* 2 (length profile))))))
(pdata-set! "p" i (vsub (pdata-ref "p" (- i (length profile)))
(vmul v (- (floor t) t)))))
; collapse the yet un-extruded part into the last vert
(for ((i (in-range (+ start (* (length profile) 1)) end)))
(pdata-set! "p" i (pdata-get "p" start))))
(recalc-normals 0)
v)))
(define (build-circle-profile n r)
(define (_ n c l)
(cond ((zero? c) l)
(else
(let ((a (* (/ c n) (* 2 3.141))))
(_ n (- c 1)
(cons (vmul (vector (sin a) (cos a) 0) r) l))))))
(_ n n '()))
(clear)
(define l (make-light 'point 'free))
(light-diffuse 0 (vector 0 0 0))
(light-diffuse l (vector 1 1 1))
(light-position l (vector 50 50 0))
(light-specular l (vector 1 1 1))
(define profile (build-circle-profile 12 0.5))
(define path (build-list 50
(lambda (n) (vmul (vector (sin (* 0.5 n)) 0 (cos (* 0.5 n))) (+ 0.5 (* 0.2 n))))))
#;(define path (build-list 10
(lambda (n) (vector (* 10 (rndf)) 0 (* 3 n)))))
(define p (with-state
; (hint-wire)
(colour (vector 0 0.5 0.5))
(specular (vector 1 1 1))
(shinyness 20)
(build-partial-extrusion profile path)))
(define v (vector 0 0 0))
(define (animate)
(set! v (partial-extrude p (fmod (* 2 (time)) (length path)) v profile path)))
(every-frame (animate))
(with-state
(wire-opacity 0.4)
(translate (vector 0 0 0))
(wire-colour (vector 0 0 1))
(hint-none)
(hint-wire)
; (hint-normal)
(backfacecull 1)
(point-width 5)
(build-extrusion profile path))