Creating a picture of a map with a recurssive function

Asked Dec 10 '16 at 15:13

Active Dec 10 '16 at 15:13

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i'm using haskell gloss for the first time and I'm having some trouble, in this code:

-- the initial c and l will be imagine for dimension 9: (-160) 160 
-- (so the square ends in the center of the window

--         column;  line;   dimension   
drawmap :: Float -> Float -> Float -> Picture
drawmap c l d = (drawline x c l d) : (drawmap xs c (l+40) d)

drawline :: Float -> Float -> Float -> Picture
drawline c l d = if (d>0) then (Translate c l $ Color red (circle 20)) : (drawline (c+40) l (d-1))
                          else (Translate c l $ Color red (circle 20))

The only question I have right now is with the type, because I need it to be the type Picture, and not [Picture], any help?

And also, how do i make this stop point:

drawline _ _ 0 = Nothing or []

I know this is not acceptable, but how do I tell it when to stop doing circles?

This is not pratical at all, is just an example very simple, if someone helps me understand this I can after apply what I really need to do.

asked Dec 10 '16 at 15:13

Dost

1. you can use `pictures` function for [Picture] -> Picture. – Junyoung Clare Jang Dec 10 '16 at 15:20
2. Just use helping function for `drawline` and make `drawline` using that helping function and `pictures` – Junyoung Clare Jang Dec 10 '16 at 15:23
P.S. use different type for Column, Line, Dimension, not just use comment. – Junyoung Clare Jang Dec 10 '16 at 15:23
I only used the comments to explain it here. – Dost Dec 10 '16 at 16:04
I have Column,Line and Dimension set as INT and I can't use int here xD – Dost Dec 10 '16 at 16:04
Then use other name, but a type, not a comment. – Junyoung Clare Jang Dec 10 '16 at 16:08
One more thing, what shoud i use in the place of: drawline _ _ 0 = Nothing or [] – Dost Dec 10 '16 at 16:13
It's my second point. Use helping function that generate [Picture] and return `[]` – Junyoung Clare Jang Dec 10 '16 at 16:31
Yes, I already solved, now i just need to place my functions to put what i want insteed of a bunch of circles in the screen. Thank you – Dost Dec 10 '16 at 16:35

Creating a picture of a map with a recurssive function

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