142 lines
4 KiB
Scheme
142 lines
4 KiB
Scheme
(clear)
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(define-struct vg (v w h))
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(define (build-vg x y)
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(make-vg
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(build-vector (* x y) (lambda (n)
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(srndvec))) x y))
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(define (vg-ref vg x y)
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(if (and (>= x 0) (>= y 0) (< x (vg-w vg)) (< y (vg-h vg)))
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(vector-ref (vg-v vg) (+ (* y (vg-w vg)) x))
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(vector 0 0 0)))
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(define (vg-lerp vg x y)
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(let* ((ix (inexact->exact (floor x))) (iy (inexact->exact (floor y)))
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(fx (- x ix)) (fy (- y iy)))
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(if (and (>= ix 0) (>= iy 0) (< (+ ix 1) (vg-w vg)) (< (+ iy 1) (vg-h vg)))
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(let ((a (vector-ref (vg-v vg) (+ (* iy (vg-w vg)) ix)))
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(b (vector-ref (vg-v vg) (+ (* (+ iy 1) (vg-w vg)) (+ ix 1)))))
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(vector (+ (* (vx b) fx) (* (vx a) (- 1 fx)))
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(+ (* (vy b) fy) (* (vy a) (- 1 fy))) 0))
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(vector 0 0 0))))
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(define (vg-set! vg x y s)
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(when (and (>= x 0) (>= y 0) (< x (vg-w vg)) (< y (vg-h vg)))
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(vector-set! (vg-v vg) (+ (* y (vg-w vg)) x) s)))
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(define (vg-blend! vg)
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(for ((x (in-range 0 (vg-w vg))))
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(for ((y (in-range 0 (vg-h vg))))
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(vg-set! vg x y
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(vadd
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(vmul (vadd
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(vadd (vg-ref vg (- x 1) y) (vg-ref vg x (- y 1)))
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(vadd (vg-ref vg (+ x 1) y) (vg-ref vg x (+ y 1))))
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(/ 1 5))
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(vmul (vg-ref vg x y) (/ 1 5)))))))
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(define (vg-turbulate! vg s)
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(for ((x (in-range 0 (vg-w vg))))
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(for ((y (in-range 0 (vg-h vg))))
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(vg-set! vg x y
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(vmul
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(let ((x (* x 0.3)) (y (* y 0.3)))
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(vector (- (noise (+ x (time)) y) 0.5)
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(- (noise (+ x (time)) (+ y 100)) 0.5) 0)) s)))))
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(define (vg-jitter! vg s)
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(for ((x (in-range 0 (vg-w vg))))
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(for ((y (in-range 0 (vg-h vg))))
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(vg-set! vg x y
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(vadd
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(vmul
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(vector (crndf) (crndf) 0) s)
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(vmul (vg-ref vg x y) (- 1 s)))))))
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(define (render-vg root vg)
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(with-state
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(wire-colour (vector 1 1 1))
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(hint-none)
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(hint-wire)
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(line-width 1)
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(hint-unlit)
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(parent root)
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(for ((x (in-range 0 (vg-w vg))))
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(for ((y (in-range 0 (vg-h vg))))
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(let ((p (build-ribbon 2)))
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(with-primitive p
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(pdata-set! "p" 0 (vector x y 0))
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(pdata-set! "p" 1 (vadd (vector x y 0)
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(vmul (vg-ref vg x y) 1)))))))))
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;----------------------------------------------------------------
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(define (vg-push-particles vg c)
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(pdata-map!
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(lambda (p)
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(let ((v (vg-lerp vg (vx p) (vy p))))0
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(if (and (zero? (vx v)) (zero? (vy v)))
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(vadd c
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(vmul (vector (crndf) (crndf) 0) 1))
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(vadd (vadd p (vmul v 0.5))
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(vmul (vector (crndf) (crndf) 0) 0.1)))))
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"p"))
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(clear)
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(define p (with-state
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(hint-none)
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(hint-points)
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(build-particles 2000)))
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(define rp (with-state
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(hint-none)
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(hint-points)
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(build-particles 2000)))
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(with-primitive p
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(pdata-map!
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(lambda (p)
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(vadd (vector 15 15 0) (vmul (vector (crndf) (crndf) 0) 1)))
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"p")
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(pdata-map!
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(lambda (c)
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(vector 1 1 1))
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"c"))
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(with-primitive rp
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(pdata-map!
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(lambda (p)
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(vadd (vector 10 15 0) (vmul (vector (crndf) (crndf) 0) 1)))
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"p")
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(pdata-map!
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(lambda (c)
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(vector 1 0.5 0.5))
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"c"))
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(define r (build-locator))
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(define v (build-vg 30 30))
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(define (animate)
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(with-primitive p
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(vg-push-particles v (vector 5 15 0)))
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(with-primitive rp
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(vg-push-particles v (vector 15 15 0)))
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(vg-turbulate! v 5))
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(every-frame (animate))
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