From 01c0f5faf98b78d44aaae7f70e0cf4229ad8ed91 Mon Sep 17 00:00:00 2001
From: Sébastien Dailly <sebastien@chimrod.com>
Date: Sat, 19 Dec 2020 20:26:26 +0100
Subject: Save the point information in each bezier curve

---
 path/builder.ml | 92 +++++++++++++++++++++++++--------------------------------
 1 file changed, 41 insertions(+), 51 deletions(-)

(limited to 'path/builder.ml')

diff --git a/path/builder.ml b/path/builder.ml
index 4fe8951..01dfb35 100755
--- a/path/builder.ml
+++ b/path/builder.ml
@@ -82,10 +82,10 @@ module Make(Point:P) = struct
             lastPoint p4 p3 p2 p1 in
 
         let bezier_point =
-          { p0 = lastPoint
-          ; p1 = p4
-          ; ctrl0 = bezier.Shapes.Bezier.ctrl0
-          ; ctrl1 = bezier.Shapes.Bezier.ctrl1
+          { p0 = p2
+          ; p1 = p1
+          ; ctrl0 = bezier.Shapes.Bezier.ctrl1
+          ; ctrl1 = bezier.Shapes.Bezier.ctrl0
           } in
 
         (* We remove the last point and add the bezier curve in the list*)
@@ -148,21 +148,23 @@ module Make(Point:P) = struct
             ; p1 = Point.empty } in
 
         let _ = List.fold_left points
-            ~init:(true, first_point, 0)
-            ~f:(fun (first, prev_point, i) point ->
-                if first then (false, prev_point, i)
+            ~init:(first_point, -1)
+            ~f:(fun (prev_point, i) point ->
+                (* In the first step, prev_point = point *)
+                if i < 0 then
+                  ( prev_point
+                  , 0)
                 else
 
                   let bezier_curve = Array.get beziers i in
-
                   Array.set curves i
-                    { p0 = prev_point
-                    ; ctrl0 = bezier_curve.Shapes.Bezier.ctrl1
-                    ; ctrl1 = bezier_curve.Shapes.Bezier.ctrl0
-                    ; p1 = point };
-
+                    { p0 = Point.copy prev_point bezier_curve.Shapes.Bezier.p0
+                    ; ctrl0 = bezier_curve.Shapes.Bezier.ctrl0
+                    ; ctrl1 = bezier_curve.Shapes.Bezier.ctrl1
+                    ; p1 = Point.copy point bezier_curve.Shapes.Bezier.p1 };
 
-                  (false, point, i + 1)
+                  ( point
+                  , i + 1)
               ) in
         curves
 
@@ -174,19 +176,16 @@ module Make(Point:P) = struct
     = fun (points, beziers) ->
 
       let path = Point.create_path () in
-      let path, last = match points with
+      let path = match points with
         | [] ->
-          ( path
-          , None )
+          ( path )
         | p1::[] ->
-          ( Point.start p1 path
-          , Some p1 )
+          ( Point.start p1 path )
         | p1::p2::[] ->
           let path =
             Point.start p1 path
             |> Point.line_to p2 in
-          ( path
-          , Some p2 )
+          ( path )
         | p0::p1::p2::[] ->
           let path = Point.start p0 path in
 
@@ -201,14 +200,13 @@ module Make(Point:P) = struct
           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
-          , Some p2 )
+          ( Point.quadratic_to p0' ctrl0 ctrl1 p2' path )
         | (p0::_ as points) ->
 
           let (let*) v f =
             match v with
             | Ok beziers -> f beziers
-            | _ -> path, None in
+            | _ -> path in
 
           let points' = List.map ~f:Point.get_coord points in
           let connexion = match beziers with
@@ -226,44 +224,36 @@ module Make(Point:P) = struct
           let path = ref path in
           let point = ref p0 in
 
-          List.iteri points
+          List.iteri
+            points
             ~f:(fun i pt ->
 
-                if i < Array.length beziers then (
-
-                  let bezier = Array.get beziers i in
+                (* 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 p0' = Point.copy pt bezier.Shapes.Bezier.p0
+                  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' = Point.copy pt bezier.Shapes.Bezier.p1 in
+                  and p1' = pt in
 
                   path := Point.quadratic_to p0' ctrl0 ctrl1 p1' (!path);
 
-                  let () = if i > 0 then
-                      point := pt in
-                  ()
+                  point := pt;
                 )
               );
-          ( !path
-          , Some !point )
+          ( !path )
       in
 
-      let path = match last with
-        | None -> path
-        | Some pt ->
-
-          (* TODO : instead of copying the last point, keeep a track for each
-             point as declared in the type P.t *)
-
-          List.fold_left beziers
-            ~init:path
-            ~f:(fun path bezier ->
-                let p0' = bezier.p0
-                and ctrl0 = Point.copy pt bezier.ctrl0
-                and ctrl1 = Point.copy pt bezier.ctrl1
-                and p1' = bezier.p1 in
-                Point.quadratic_to p0' ctrl0 ctrl1 p1' path
-              )
+      let path = 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 p1' = bezier.p1 in
+              Point.quadratic_to p0' ctrl0 ctrl1 p1' path
+            )
       in Point.stop path
 end
-- 
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