ikarus/benchmarks.larceny/src/pnpoly.scm

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;;; PNPOLY - Test if a point is contained in a 2D polygon.
(define (pt-in-poly2 xp yp x y)
(let loop ((c #f) (i (- (FLOATvector-length xp) 1)) (j 0))
(if (< i 0)
c
(if (or (and (or (FLOAT> (FLOATvector-ref yp i) y)
(FLOAT>= y (FLOATvector-ref yp j)))
(or (FLOAT> (FLOATvector-ref yp j) y)
(FLOAT>= y (FLOATvector-ref yp i))))
(FLOAT>= x
(FLOAT+ (FLOATvector-ref xp i)
(FLOAT/ (FLOAT*
(FLOAT- (FLOATvector-ref xp j)
(FLOATvector-ref xp i))
(FLOAT- y (FLOATvector-ref yp i)))
(FLOAT- (FLOATvector-ref yp j)
(FLOATvector-ref yp i))))))
(loop c (- i 1) i)
(loop (not c) (- i 1) i)))))
(define (run)
(let ((count 0)
(xp (FLOATvector-const 0. 1. 1. 0. 0. 1. -.5 -1. -1. -2. -2.5
-2. -1.5 -.5 1. 1. 0. -.5 -1. -.5))
(yp (FLOATvector-const 0. 0. 1. 1. 2. 3. 2. 3. 0. -.5 -1.
-1.5 -2. -2. -1.5 -1. -.5 -1. -1. -.5)))
(if (pt-in-poly2 xp yp .5 .5) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp .5 1.5) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp -.5 1.5) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp .75 2.25) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp 0. 2.01) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp -.5 2.5) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp -1. -.5) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp -1.5 .5) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp -2.25 -1.) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp .5 -.25) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp .5 -1.25) (set! count (+ count 1)))
(if (pt-in-poly2 xp yp -.5 -2.5) (set! count (+ count 1)))
count))
(define (main . args)
(run-benchmark
"pnpoly"
pnpoly-iters
(lambda (result)
(and (number? result) (= result 6)))
(lambda () (lambda () (run)))))