Update

1 files changed, 103 insertions, 85 deletions

diff --git a/path/builder.ml b/path/builder.ml
index 01dfb35..2774cae 100755
--- a/path/builder.ml
+++ b/path/builder.ml
@@ -10,6 +10,11 @@ module type P = sig
 
   val copy : t -> Gg.v2 -> t
 
+end
+
+module type REPR = sig
+  type t
+
   type 'a repr
 
   val create_path
@@ -23,7 +28,7 @@ module type P = sig
     : t -> 'a repr -> 'a repr
 
   val quadratic_to
-    : t -> t -> t -> t -> 'a repr -> 'a repr
+    : t -> Gg.v2 -> Gg.v2 -> t -> 'a repr -> 'a repr
 
   val stop
     : 'a repr -> 'a repr
@@ -34,8 +39,8 @@ module Make(Point:P) = struct
   (** Point creation  **)
 
   type bezier =
-    { p0:Point.t      (* The starting point *)
-    ; p1:Point.t      (* The end point *)
+    { p0:Point.t    (* The starting point *)
+    ; p1:Point.t    (* The end point *)
     ; ctrl0:Gg.v2   (* The control point *)
     ; ctrl1:Gg.v2 } (* The control point *)
 
@@ -169,91 +174,104 @@ module Make(Point:P) = struct
         curves
 
 
-  (** Drawing path **)
-
-  let draw
-    : t -> 'a Point.repr
-    = fun (points, beziers) ->
-
-      let path = Point.create_path () in
-      let path = match points with
-        | [] ->
-          ( path )
-        | p1::[] ->
-          ( Point.start p1 path )
-        | p1::p2::[] ->
-          let path =
-            Point.start p1 path
-            |> Point.line_to p2 in
-          ( path )
-        | p0::p1::p2::[] ->
-          let path = Point.start p0 path in
-
-          let b = Shapes.Bezier.three_points_quadratic
-              (Point.get_coord p0)
-              (Point.get_coord p1)
-              (Point.get_coord p2)
-                  |> Shapes.Bezier.quadratic_to_cubic in
-
-          let p0' = Point.copy p0 b.Shapes.Bezier.p0
-          and ctrl0 = Point.copy p0 b.Shapes.Bezier.ctrl0
-          and ctrl1 = Point.copy p1 b.Shapes.Bezier.ctrl1
-          and p2' = Point.copy p1 b.Shapes.Bezier.p1 in
-
-          ( Point.quadratic_to p0' ctrl0 ctrl1 p2' path )
-        | (p0::_ as points) ->
-
-          let (let*) v f =
-            match v with
-            | Ok beziers -> f beziers
-            | _ -> path in
-
-          let points' = List.map ~f:Point.get_coord points in
-          let connexion = match beziers with
-            | [] -> None
-            | hd ::_ -> Some (Point.get_coord hd.p1) in
-
-          let* beziers = Shapes.Bspline.to_bezier ?connexion1:connexion points' in
-
-          (* Stdlib does not provide fold_left_i function and we need to map
-             each bezier point with the associated point in the curve.
-
-             So I use references here for keeping each result element
-
-          *)
-          let path = ref path in
-          let point = ref p0 in
-
-          List.iteri
-            points
-            ~f:(fun i pt ->
-
-                (* The first iteration is ignored, as we need both previous and
-                   current point for the two point in the curve *)
-                if i > 0 then (
-
-                  let bezier = Array.get beziers (i - 1) in
-                  let p0' = !point
-                  and ctrl0 = Point.copy (!point) bezier.Shapes.Bezier.ctrl0
-                  and ctrl1 = Point.copy pt bezier.Shapes.Bezier.ctrl1
-                  and p1' = pt in
-
-                  path := Point.quadratic_to p0' ctrl0 ctrl1 p1' (!path);
-
-                  point := pt;
-                )
-              );
-          ( !path )
-      in
-
-      let path = List.fold_left beziers
+  module Draw(Repr:REPR with type t = Point.t) = struct
+
+    (** Drawing path **)
+
+    let draw
+      : t -> 'a Repr.repr
+      = fun (points, beziers) ->
+
+        let path = Repr.create_path () in
+
+        (* Represent the last points *)
+        let path = match points with
+          | [] ->
+            ( path )
+          | p1::[] ->
+            ( Repr.start p1 path )
+          | p1::p2::[] ->
+            let path =
+              Repr.start p1 path
+              |> Repr.line_to p2 in
+            ( path )
+          | p0::p1::p2::[] ->
+            let path = Repr.start p0 path in
+
+            let b = Shapes.Bezier.quadratic_to_cubic
+              @@ Shapes.Bezier.three_points_quadratic
+                (Point.get_coord p0)
+                (Point.get_coord p1)
+                (Point.get_coord p2)
+            in
+
+            let p0' = Point.copy p0 b.Shapes.Bezier.p0
+            and p2' = Point.copy p1 b.Shapes.Bezier.p1 in
+
+            ( Repr.quadratic_to
+                p0'
+                b.Shapes.Bezier.ctrl0
+                b.Shapes.Bezier.ctrl1
+                p2'
+                path )
+          | (p0::_ as points) ->
+
+            let (let*) v f =
+              match v with
+              | Ok beziers -> f beziers
+              | _ -> path in
+
+            let points' = List.map ~f:Point.get_coord points in
+            let connexion = match beziers with
+              | [] -> None
+              | hd ::_ -> Some (Point.get_coord hd.p1) in
+
+            let* beziers = Shapes.Bspline.to_bezier ?connexion1:connexion points' in
+
+            (* Stdlib does not provide fold_left_i function and we need to map
+               each bezier point with the associated point in the curve.
+
+               So I use references here for keeping each result element
+
+            *)
+            let path = ref path in
+            let point = ref p0 in
+
+            List.iteri
+              points
+              ~f:(fun i pt ->
+
+                  (* The first iteration is ignored, as we need both previous and
+                     current point for the two point in the curve.
+
+                     Do not forget that there is always n-1 bezier curve for n
+                     points *)
+                  if i > 0 then (
+
+                    let bezier = Array.get beziers (i - 1) in
+
+                    path := Repr.quadratic_to
+                        !point
+                        bezier.Shapes.Bezier.ctrl0
+                        bezier.Shapes.Bezier.ctrl1
+                        pt
+                        (!path);
+                    point := pt;
+                  )
+                );
+            ( !path )
+        in
+
+        (* Now represent the already evaluated points. Much easer to do, just
+           iterate on them *)
+        Repr.stop @@ List.fold_left beziers
           ~init:path
           ~f:(fun path bezier ->
               let p0' = bezier.p0
-              and ctrl0 = Point.copy bezier.p0 bezier.ctrl0
-              and ctrl1 = Point.copy bezier.p1 bezier.ctrl1
+              and ctrl0 = bezier.ctrl0
+              and ctrl1 = bezier.ctrl1
               and p1' = bezier.p1 in
-              Point.quadratic_to p0' ctrl0 ctrl1 p1' path
+              Repr.quadratic_to p0' ctrl0 ctrl1 p1' path
             )
-      in Point.stop path
+  end
 end