resolved a merge conflict

examples/complex.ml

@@ -0,0 +1,34 @@
+open Joy.Shape
+
+(*
+   Complex shapes can also be created from lists of shapes.
+   This allows us to apply any of the libraries' transformations to a group of
+   shapes, like we're doing here with translate
+*)
+
+(* creates a list containing numbers between a and b *)
+let rec range a b = if a > b then [] else a :: range (a + 1) b
+
+(* creates a list of (int * int) tuples,
+   containing every combination of the elements of the two passsed lists *)
+let cartesian_product l l' =
+  List.concat (List.map (fun e -> List.map (fun e' -> (e, e')) l') l)
+
+let () =
+  init ();
+  (* radius which also acts as grid spacing *)
+  let radius = 50 in
+  let half_radius = radius / 2 in
+  (* creating a grid with cartesian_product *)
+  let coords = cartesian_product (range (-5) 5) (range (-5) 5) in
+  (* using map to turn that into a complex shape that is a grid of circles *)
+  let complex_shape =
+    complex
+      (List.map
+         (fun (x, y) -> circle ~x:(x * radius) ~y:(y * radius) radius)
+         coords)
+  in
+  (* translating that complex shape by radius / 2 *)
+  let complex_transformed = translate half_radius half_radius complex_shape in
+  show [ complex_shape; complex_transformed ];
+  close ()

examples/dune

@@ -92,3 +92,8 @@
  (name higher_transforms)
  (modules higher_transforms)
  (libraries joy))
+
+(executable
+ (name complex)
+ (modules complex)
+ (libraries joy))

examples/higher_transforms.ml

@@ -1,21 +1,20 @@
 open Joy.Shape
 
-(* Higher order transformations can be composed with `comp`, 
+(* Higher order transformations can be composed with `comp`,
    which applies its function args right-to-left.
    This allows us to create complex series transformations,
    that can be applied iteratively *)
 let transform = compose (translate 10 10) (scale 0.9)
-
 let rec range a b = if a > b then [] else a :: range (a + 1) b
 
-let () = 
+let () =
   init ();
-  let initial = rectangle ~x:(-250) ~y:(-250) 100 100 in 
-  let match_list l = 
-    match l with 
-    | [] -> [(transform initial)]
-    | last :: _ -> (transform last) :: l
-  in 
-  let shapes = List.fold_right (fun _ acc -> (match_list acc)) (range 0 32) [] in
+  let initial = rectangle ~x:(-250) ~y:(-250) 100 100 in
+  let match_list l =
+    match l with
+    | [] -> [ transform initial ]
+    | last :: _ -> transform last :: l
+  in
+  let shapes = List.fold_right (fun _ acc -> match_list acc) (range 0 32) [] in
   show shapes;
-  close ()
+  close ()

lib/shape.ml

@@ -11,6 +11,7 @@ type shape =
   | Rectangle of rectangle
   | Ellipse of ellipse
   | Line of line
+  | Complex of shape list
 
 type shapes = shape list
 
@@ -24,7 +25,7 @@ let draw_line x1 y1 x2 y2 = draw_poly_line [| (x1, y1); (x2, y2) |]
 let denormalize point =
   { x = point.x + canvas_mid.x; y = point.y + canvas_mid.y }
 
-let render_shape s =
+let rec render_shape s =
   match s with
   | Circle circle ->
       draw_circle (denormalize circle.c).x (denormalize circle.c).y
@@ -39,6 +40,7 @@ let render_shape s =
       let a = denormalize line.a in
       let b = denormalize line.b in
       draw_line a.x a.y b.x b.y
+  | Complex complex -> List.iter render_shape complex
 
 let circle ?x ?y r =
   match (x, y) with
@@ -60,7 +62,10 @@ let line ?x1 ?y1 x2 y2 =
   | Some x, Some y -> Line { a = { x; y }; b = { x = x2; y = y2 } }
   | _ -> Line { a = { x = 0; y = 0 }; b = { x = x2; y = y2 } }
 
-let translate dx dy shape =
+let complex shapes =
+  match shapes with _ :: _ -> Complex shapes | [] -> Complex []
+
+let rec translate dx dy shape =
   match shape with
   | Circle circle ->
       Circle { circle with c = { x = circle.c.x + dx; y = circle.c.y + dy } }
@@ -79,8 +84,9 @@ let translate dx dy shape =
           a = { x = line.a.x + dx; y = line.a.y + dy };
           b = { x = line.b.x + dx; y = line.b.y + dy };
         }
+  | Complex shapes -> Complex (List.map (translate dx dy) shapes)
 
-let scale factor s =
+let rec scale factor s =
   let round x = int_of_float (x +. 0.5) in
   let scale_length len fact = round (float_of_int len *. sqrt fact) in
   match s with
@@ -95,6 +101,7 @@ let scale factor s =
         (scale_length ellipse'.rx factor)
         (scale_length ellipse'.ry factor)
   | Line _line' -> failwith "Not Implemented"
+  | Complex shapes -> Complex (List.map (scale factor) shapes)
 
 let show shapes = List.iter render_shape shapes
 
@@ -112,7 +119,7 @@ let rot { x : int; y : int } degrees =
   let dx, dy = bi_to_uni dx dy in
   { x = dx; y = dy }
 
-let rotate degrees shape =
+let rec rotate degrees shape =
   match shape with
   | Circle circle -> Circle { c = rot circle.c degrees; radius = circle.radius }
   | Rectangle rectangle ->
@@ -124,9 +131,8 @@ let rotate degrees shape =
         }
   | Ellipse ellipse ->
       Ellipse { c = rot ellipse.c degrees; rx = ellipse.rx; ry = ellipse.ry }
-  | Line line -> 
-      Line { a= rot line.a degrees; b = rot line.b degrees }
-
+  | Line _line -> failwith "Not Implemented"
+  | Complex shapes -> Complex (List.map (rotate degrees) shapes)
 
 let compose f g x = g (f x)
 

lib/shape.mli

@@ -5,14 +5,13 @@ val render_shape : shape -> unit
 val circle : ?x:int -> ?y:int -> int -> shape
 val rectangle : ?x:int -> ?y:int -> int -> int -> shape
 val ellipse : ?x:int -> ?y:int -> int -> int -> shape
+val complex : shape list -> shape
 val line : ?x1:int -> ?y1:int -> int -> int -> shape
 val translate : int -> int -> shape -> shape
 val show : shape list -> unit
 val scale : float -> shape -> shape
 val rotate : int -> shape -> shape
-
 val compose : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c
-
 val draw_axes : bool -> unit
 val set_dimensions : int -> int -> unit
 val init : unit -> unit