Thank you, I just implemented a UCBLogo compatible `arc`: (define (arc angle radius) (let* ([alpha (* 2 (asin (/ 1 (* 2 radius))))] [rangle (* pi (/ angle 180))] [n (abs (/ rangle alpha))] [astep (if (> angle 0) (- alpha) alpha)]) (tprompt (move radius) (turn (if (> angle 0) -90 90)) (for ([i (in-range n)]) (draw 1) (turn/radians astep))) (turn (- angle))))
Greetings. Killian Zhuo (KDr2, https://kdr2.com) On Tuesday, February 2, 2021, 11:32:59 AM GMT+8, making-a-racket <[email protected]> wrote: Turtles can only turn or move forward with or without drawing. To draw an arc, you'll need to combine these methods to do that. I highly recommend the book Turtle Geometry by Abelson and diSessa. Below you can find an excerpt of the book that talks about drawing circles and arcs. Here's an implementation of a circle in Racket using the turtle library you referenced. #lang racket (require graphics/turtles) (turtles #t) (for ([i (in-range 360)]) (draw 1) (turn 1)) On Monday, February 1, 2021 at 5:54:05 PM UTC-6 [email protected] wrote: > I am imitating the Logo API to draw some shapes with `graphics/turtles`, but > in it I only find functions to draw lines, is there a way to draw an arc? > > > > Greetings. > > Killian Zhuo (KDr2, https://kdr2.com) -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/aea4ad53-162e-4924-87ed-1e7311c2aef3n%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/625594723.1001568.1612254850718%40mail.yahoo.com.
