3 files changed, 90 insertions, 0 deletions
diff --git a/script.it/shapes/tools/dune b/script.it/shapes/tools/dune
new file mode 100755
index 0000000..a2c3fdb
--- /dev/null
+++ b/script.it/shapes/tools/dune
@@ -0,0 +1,6 @@
+(library
+ (name tools)
+ (libraries 
+   gg
+   )
+  )
diff --git a/script.it/shapes/tools/utils.ml b/script.it/shapes/tools/utils.ml
new file mode 100755
index 0000000..b8a473f
--- /dev/null
+++ b/script.it/shapes/tools/utils.ml
@@ -0,0 +1,63 @@
+open Gg.V2
+
+let norm_angle vect =
+  mod_float
+    ((angle vect) +. Gg.Float.two_pi)
+    Gg.Float.two_pi
+
+
+let intersection
+  : (Gg.v2 * Gg.v2) -> (Gg.v2 * Gg.v2) -> Gg.v2 option
+  = fun (p0, p1) (p2, p3) ->
+    let i = p1 - p0
+    and j = p3 - p2 in
+
+    let d = (x i *. y j) -. (y i *. x j) in
+    if Float.( (abs d) <= 0.01 ) then
+      None
+    else
+      let m = ((x i) *. (y p0)
+               -. (x i) *. (y p2)
+               -. (y i) *. (x p0)
+               +. (y i) *. (x p2)) /. d in
+      Some (p2 + m * j)
+      (*
+      let k = ((x j) *. (y p0)
+               -. (x j) *. (y p2)
+               -. (y j) *. (x p0)
+               +. (y j) *. (x p2)) /. d in
+      Some (p0 + k * i)
+      *)
+
+
+let center
+  : Gg.v2 -> Gg.v2 -> Gg.v2 -> Gg.v2 option
+  = fun p0 p1 p2 ->
+    (* deltas *)
+    let d1 = p1 - p0
+    and d2 = p2 - p1 in
+
+    (* perpendiculars *)
+    let d1p = ortho d1
+    and d2p = ortho d2 in
+
+    (* Chord midpoints *)
+    let m1 = half (p0 + p1)
+    and m2 = half (p1 + p2) in
+
+    (* midpoint offsets *)
+    let m1n = m1 + d1p
+    and m2n = m2 + d2p in
+
+    intersection (m1, m1n) (m2, m2n)
+
+let rotate
+  : Gg.v2 -> float -> Gg.v2
+  = fun p0 theta ->
+    let r = x (to_polar p0) in
+    of_polar (v r theta)
+
+let equal_point
+  : float -> Gg.v2 -> Gg.v2 -> bool
+  = fun eps p0 p1 ->
+    Gg.V2.equal_f (fun v0 v1 ->  (Float.abs (v1 -. v0)) <= eps ) p0 p1
diff --git a/script.it/shapes/tools/utils.mli b/script.it/shapes/tools/utils.mli
new file mode 100755
index 0000000..4e12906
--- /dev/null
+++ b/script.it/shapes/tools/utils.mli
@@ -0,0 +1,21 @@
+(** Return a normalize angle *)
+val norm_angle 
+  : Gg.v2 -> float
+
+(** return the interesction for two segments *)
+val intersection
+  : (Gg.v2 * Gg.v2) -> (Gg.v2 * Gg.v2) -> Gg.v2 option
+
+(** Return the center of the cercle for three points  
+    None if the point cannot be evaluated
+*)
+val center
+  : Gg.v2 -> Gg.v2 -> Gg.v2 -> Gg.v2 option
+
+(** Rotate the vector by the given angle *)
+val rotate
+  : Gg.v2 -> float -> Gg.v2
+
+(** Test equality between two points *)
+val equal_point
+  : float -> Gg.v2 -> Gg.v2 -> bool