>>106307320
>Instead of trying to figure out the angles, measure the coordinates and use trigonometry to aim towards them.
I'm going to have to reteach myself some minimal trig for that. It's been a while. I did work on it a bit more, and noticed my offset for the circle wasn't quite right so I fixed that, and that alone made things much closer as the attached gif will show.
- Red is the official naval flag, and
- Blue is my flag with perfectly even intervals for the rays.
- The angular differences are very small.

(define (japan-naval #:width [width 300]
#:fg [fg (make-color 188 0 45)]
#:bg [bg "white"])
(let* ([height (/ width 3/2)]
[radius (/ width 6)]
[offset (- radius (/ radius 3))]
[uncropped (overlay/offset
(overlay
(circle radius "solid" fg)
(polygon
(map (lambda (xy) (apply make-posn xy))
(rays 16 width)) "solid" fg))
;; move rectangle $offset pixels to the right
offset 0
(rectangle width height "solid" bg))]
[x (- (/ (image-width uncropped) 2) (/ width 2) (- offset))]
[y (- (/ (image-height uncropped) 2) (/ height 2))]
[cropped (crop x y width height uncropped)])
cropped))