Merge branch 'main' into refactor

README.md

@@ -38,7 +38,7 @@ let () =
 
 and renders this:
 
-![circle](/tutorial-circle.png)
+![circle](/tutorial/tutorial-circle.png)
 
 Let's break this down. `init` does all the behind-the-scenes render magic that 
 allows our shape to be drawn to an image file. `circle 100` creates a circle at 
@@ -48,7 +48,7 @@ like this:
 
 `let c = circle ~c:(point 0 100) 100`
 
-![offset-circle](/tutorial-circle-offset.png)
+![offset-circle](/tutorial/tutorial-circle-offset.png)
 
 Notice the call to `show`, the circle is placed within a list. This is how we 
 render shapes in Joy. Placing our shape arguments in a list allows us to draw 
@@ -73,7 +73,7 @@ let () =
     write ()
 ```
 
-![rotate](/tutorial-rotate.png)
+![rotate](/tutorial/tutorial-rotate.png)
 
 Transformations can also be composed together:
 
@@ -92,7 +92,7 @@ let rect = rectangle 100 100 in
 let spiral = repeat 16 (rotate 45) rect
 ```
 
-![spiral](/tutorial-spiral.png)
+![spiral](/tutorial/tutorial-spiral.png)
 
 This is how we build more complex shapes out of the simple primitives and 
 transformations in the library. It may look a little intimidating if you are new
@@ -131,7 +131,7 @@ let l = line (point (-250) 250) in
 let bunch = complex [ c; r; e; l ]
 ```
 
-![complex](/tutorial-complex.png)
+![complex](/tutorial/tutorial-complex.png)
 
 # Going further
 

examples/dune

@@ -137,3 +137,8 @@
  (name smile)
  (modules smile)
  (libraries joy))
+
+(executable
+  (name simple_rotate_ellipse)
+  (modules simple_rotate_ellipse)
+  (libraries joy))

examples/rotate_ellipse.ml

@@ -4,7 +4,7 @@ let max = 32.
 let rec range a b = if a > b then [] else a :: range (a +. 1.) b
 
 let _ =
-  init ();
+  init ~size:(500, 500) ~axes:true ();
   let ell = ellipse 100 50 |> translate 60 60 in
   let nums = range 0. max in
   let rotated =

examples/simple_rotate_ellipse.ml

@@ -0,0 +1,7 @@
+open Joy
+
+let _ =
+  init ();
+  let ell = ellipse 100 50 in
+  show [ ell; ell |> rotate 60 ];
+  write ~filename:"simple_rotate_ellipse.png" ()

lib/backend_cairo.ml

@@ -41,10 +41,15 @@ let draw_ellipse ctx (cx, cy) rx ry rotation stroke fill =
   (* Save the current transformation matrix *)
   let save_matrix = Cairo.get_matrix ctx.cairo_ctx in
 
+  (* Apply rotation *)
+  let radians = Util.to_radians rotation in
+  Cairo.rotate ctx.cairo_ctx radians;
+
   (* Translate and scale to create an ellipse from a circle *)
   Cairo.translate ctx.cairo_ctx cx (Float.neg cy);
-  Cairo.rotate ctx.cairo_ctx rotation;
   Cairo.scale ctx.cairo_ctx rx ry;
+
+  (* Arc from 0 to 2pi is a circle *)
   Cairo.arc ctx.cairo_ctx 0. 0. ~r:1. ~a1:0. ~a2:(2. *. Float.pi);
 
   (* Restore the original transformation matrix *)

lib/shape.ml

@@ -7,7 +7,7 @@ type ellipse = {
   c : float point;
   rx : float;
   ry : float;
-  rotation : float;
+  rotation : int;
   stroke : color;
   fill : color;
 }
@@ -27,7 +27,7 @@ let point x y =
   let x, y = (float_of_int x, float_of_int y) in
   { x; y }
 
-let origin = { x = 0.; y = 0. }
+let origin = point 0 0
 
 let circle ?(c = origin) r =
   Circle
@@ -52,8 +52,7 @@ let rectangle ?(c = origin) width height =
 
 let ellipse ?(c = origin) rx ry =
   let rx, ry = (float_of_int rx, float_of_int ry) in
-  Ellipse
-    { c; rx; ry; stroke = Color.black; fill = Color.transparent; rotation = 0. }
+  Ellipse { c; rx; ry; stroke = Color.black; fill = Color.transparent; rotation = 0 }
 
 let line ?(a = origin) b = Line { a; b; stroke = Color.black }
 

lib/shape.mli

@@ -6,7 +6,7 @@ type ellipse = {
   c : float point;
   rx : float;
   ry : float;
-  rotation : float;
+  rotation : int;
   stroke : color;
   fill : color;
 }

lib/transform.ml

@@ -1,4 +1,5 @@
 open Shape
+open Util
 
 type transformation = shape -> shape
 
@@ -64,8 +65,6 @@ let rec scale factor = function
         }
   | Complex shapes -> Complex (List.map (scale factor) shapes)
 
-let to_radians degrees = float_of_int degrees *. Stdlib.Float.pi /. 180.
-
 let to_polar point =
   let { x; y } = point in
   (sqrt ((x *. x) +. (y *. y)), atan2 y x)
@@ -86,7 +85,7 @@ let rec rotate degrees = function
         {
           ellipse' with
           c = rotate_point degrees ellipse'.c;
-          rotation = ellipse'.rotation +. to_radians degrees;
+          rotation = ellipse'.rotation + degrees;
         }
   | Line line' ->
       Line

lib/util.ml

@@ -36,4 +36,4 @@ let rec partition n ?(step = 0) lst =
 
 (* Misc *)
 let range n = List.init n Fun.id
-let to_radians degrees = degrees *. Stdlib.Float.pi /. 180.
+let to_radians degrees = (float_of_int degrees) *. Stdlib.Float.pi /. 180.

lib/util.mli

@@ -10,4 +10,4 @@ val ( >> ) : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c
 val take : int -> 'a list -> 'a list * 'a list
 val partition : int -> ?step:int -> 'a list -> 'a list list
 val range : int -> int list
-val to_radians : float -> float
+val to_radians : int -> float