From 35c7ca2324f9d8eb22d70f0d329827c555357f9d Mon Sep 17 00:00:00 2001
From: Damien Seguin <dmnsgn@gmail.com>
Date: Thu, 30 Jun 2022 16:52:25 +0100
Subject: [PATCH] feat: change hitTestPlane signature to use plane

- optimise ray
---
 ray.js      | 25 ++++++++++++++-----------
 test/ray.js | 12 ++++++------
 2 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/ray.js b/ray.js
index 34f4a19..b068ee2 100644
--- a/ray.js
+++ b/ray.js
@@ -42,32 +42,35 @@ export function create() {
 }
 
 /**
- * Determines if a ray intersect a plane
+ * Determines if a ray intersect a plane and set intersection point
  * https://www.cs.princeton.edu/courses/archive/fall00/cs426/lectures/raycast/sld017.htm
  * @param {ray} ray
- * @param {import("pex-math").vec3} point
- * @param {import("pex-math").vec3} normal
+ * @param {plane} plane
  * @param {import("pex-math").vec3} out
  * @returns {number}
  */
-export function hitTestPlane(ray, point, normal, out = vec3.create()) {
-  const origin = vec3.set(TEMP_0, ray[0]);
-  const direction = vec3.set(TEMP_1, ray[1]);
+export function hitTestPlane(
+  [origin, direction],
+  [point, normal],
+  out = vec3.create()
+) {
+  vec3.set(TEMP_0, origin);
+  vec3.set(TEMP_1, direction);
 
-  const dotDirectionNormal = vec3.dot(direction, normal);
+  const dotDirectionNormal = vec3.dot(TEMP_1, normal);
   if (dotDirectionNormal === 0) return Intersections.SamePlane;
 
-  point = vec3.set(TEMP_2, point);
+  vec3.set(TEMP_2, point);
 
-  const t = vec3.dot(vec3.sub(point, origin), normal) / dotDirectionNormal;
+  const t = vec3.dot(vec3.sub(TEMP_2, TEMP_0), normal) / dotDirectionNormal;
   if (t < 0) return Intersections.Parallel;
 
-  vec3.set(out, vec3.add(origin, vec3.scale(direction, t)));
+  vec3.set(out, vec3.add(TEMP_0, vec3.scale(TEMP_1, t)));
   return Intersections.Intersect;
 }
 
 /**
- * Determines if a ray intersect a triangle
+ * Determines if a ray intersect a triangle and set intersection point
  * http://geomalgorithms.com/a06-_intersect-2.html#intersect3D_RayTriangle()
  * @param {ray} ray
  * @param {triangle} triangle
diff --git a/test/ray.js b/test/ray.js
index 1efafa9..b7afa6b 100644
--- a/test/ray.js
+++ b/test/ray.js
@@ -20,26 +20,26 @@ describe("ray", () => {
   describe("hitTestPlane()", () => {
     it("should return 1 if the ray is intersecting", () => {
       deepEqual(
-        ray.hitTestPlane(Y_UP_RAY, ...Y_UP_PLANE),
+        ray.hitTestPlane(Y_UP_RAY, Y_UP_PLANE),
         ray.Intersections.Intersect
       );
       deepEqual(
-        ray.hitTestPlane(Y_DOWN_RAY, ...Y_UP_PLANE),
+        ray.hitTestPlane(Y_DOWN_RAY, Y_UP_PLANE),
         ray.Intersections.Intersect
       );
       deepEqual(
-        ray.hitTestPlane(XYZ_RAY, ...Y_UP_PLANE),
+        ray.hitTestPlane(XYZ_RAY, Y_UP_PLANE),
         ray.Intersections.Intersect
       );
     });
     it("should set the plane intersection point", () => {
       const out = [];
-      ray.hitTestPlane(Y_UP_RAY, ...Y_UP_PLANE, out);
+      ray.hitTestPlane(Y_UP_RAY, Y_UP_PLANE, out);
       deepEqual(out, ORIGIN);
     });
     it("should return -1 if the ray is not intersecting (ray on the plane)", () => {
       deepEqual(
-        ray.hitTestPlane(Z_UP_RAY, ...Y_UP_PLANE),
+        ray.hitTestPlane(Z_UP_RAY, Y_UP_PLANE),
         ray.Intersections.SamePlane
       );
     });
@@ -50,7 +50,7 @@ describe("ray", () => {
             [0, 1, 0],
             [0, 1, 1],
           ],
-          ...Y_UP_PLANE
+          Y_UP_PLANE
         ),
         ray.Intersections.Parallel
       );