From 97a7529081c2bfa6bddf5f2fd8d32f3b01e17219 Mon Sep 17 00:00:00 2001
From: William Candillon <wcandillon@gmail.com>
Date: Wed, 29 Apr 2020 12:07:25 +0200
Subject: [PATCH] =?UTF-8?q?feat(=E2=A8=AF):=20New=20vector=20functions?=
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---
 packages/core/src/Vectors.ts                | 23 ++++++++++++++++++---
 packages/core/src/__tests__/Vectors.test.ts |  4 ++--
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/packages/core/src/Vectors.ts b/packages/core/src/Vectors.ts
index 7d832ca9..02d7d927 100644
--- a/packages/core/src/Vectors.ts
+++ b/packages/core/src/Vectors.ts
@@ -47,8 +47,11 @@ const apply = (fn: Fn, ...vectors: Adaptable[]) => ({
 
 const add = (...vectors: BinArgOp) => apply(Animated.add, ...vectors);
 const sub = (...vectors: BinArgOp) => apply(Animated.sub, ...vectors);
-const dot = (...vectors: BinArgOp) => apply(Animated.multiply, ...vectors);
 const div = (...vectors: BinArgOp) => apply(Animated.divide, ...vectors);
+const mul = (...vectors: BinArgOp) => apply(Animated.multiply, ...vectors);
+const pow = (...vectors: [Adaptable, number]) =>
+  apply(Animated.pow, ...vectors);
+const sqrt = (...vectors: SingleArgOp) => apply(Animated.sqrt, ...vectors);
 const cos = (...vectors: SingleArgOp) => apply(Animated.cos, ...vectors);
 const sin = (...vectors: SingleArgOp) => apply(Animated.sin, ...vectors);
 const min = (vector: Adaptable, value: Animated.Adaptable<number>) =>
@@ -58,7 +61,7 @@ const max = (vector: Adaptable, value: Animated.Adaptable<number>) =>
 const clamp = (value: Adaptable, minVec: Adaptable, maxVec: Adaptable) =>
   apply(clamp1, value, minVec, maxVec);
 
-const invert = (a: Adaptable) => dot(-1, a);
+const invert = (a: Adaptable) => mul(-1, a);
 
 const set = (a: Vector<Animated.Value<number>>, b: Adaptable) =>
   block([
@@ -66,6 +69,14 @@ const set = (a: Vector<Animated.Value<number>>, b: Adaptable) =>
     Animated.set(a.y, isAdaptable(b) ? b : b.y),
   ]);
 
+const length = (v: Vector) =>
+  Animated.sqrt(Animated.add(Animated.pow(v.x, 2), Animated.pow(v.y, 2)));
+const normalize = (v: Vector) => div(v, length(v));
+const dot = (v1: Vector, v2: Vector) =>
+  add(Animated.multiply(v1.x, v2.x), Animated.multiply(v1.y, v2.y));
+const cross = (v1: Vector, v2: Vector) =>
+  sub(Animated.multiply(v1.x, v2.y), Animated.multiply(v1.y, v2.x));
+
 export const vec = {
   create,
   createValue,
@@ -74,8 +85,11 @@ export const vec = {
   sub,
   dot,
   div,
-  multiply: dot,
+  mul,
+  multiply: mul,
   divide: div,
+  pow,
+  sqrt,
   set,
   clamp,
   apply,
@@ -83,4 +97,7 @@ export const vec = {
   max,
   cos,
   sin,
+  length,
+  normalize,
+  cross,
 };
diff --git a/packages/core/src/__tests__/Vectors.test.ts b/packages/core/src/__tests__/Vectors.test.ts
index 985d729d..37fdbcf6 100644
--- a/packages/core/src/__tests__/Vectors.test.ts
+++ b/packages/core/src/__tests__/Vectors.test.ts
@@ -70,8 +70,8 @@ test("multiply", () => {
   const c = vec.create(1, 1);
   const d = vec.create(2, 2);
   const result = vec.createValue(2, 2);
-  expect(vec.dot(a, b, c, d)).toEqual(result);
-  expect(vec.dot(2, 1, 1, 1)).toEqual(result);
+  expect(vec.mul(a, b, c, d)).toEqual(result);
+  expect(vec.mul(2, 1, 1, 1)).toEqual(result);
 });
 
 test("divide", () => {