From e9d314ab38c7b3f3da0c10794352efa5c949e9e8 Mon Sep 17 00:00:00 2001
From: Alexander Rose <alexander.rose@weirdbyte.de>
Date: Wed, 11 Jul 2018 19:33:22 -0700
Subject: [PATCH] Vec3 improvements (slerp, exactEquals, equals)
---
src/mol-math/linear-algebra/3d/vec3.ts | 32 ++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/src/mol-math/linear-algebra/3d/vec3.ts b/src/mol-math/linear-algebra/3d/vec3.ts
index 071ce1785..1d87731d1 100644
--- a/src/mol-math/linear-algebra/3d/vec3.ts
+++ b/src/mol-math/linear-algebra/3d/vec3.ts
@@ -18,8 +18,8 @@
*/
import Mat4 from './mat4';
-import { Quat, Mat3 } from '../3d';
-import { spline as _spline } from '../../interpolate'
+import { Quat, Mat3, EPSILON } from '../3d';
+import { spline as _spline, clamp } from '../../interpolate'
interface Vec3 extends Array<number> { [d: number]: number, '@type': 'vec3', length: 3 }
@@ -124,6 +124,7 @@ namespace Vec3 {
return out;
}
+ /** Scales b, then adds a and b together */
export function scaleAndAdd(out: Vec3, a: Vec3, b: Vec3, scale: number) {
out[0] = a[0] + (b[0] * scale);
out[1] = a[1] + (b[1] * scale);
@@ -244,6 +245,15 @@ namespace Vec3 {
return out;
}
+ const slerpRelVec = Vec3.zero()
+ export function slerp(out: Vec3, a: Vec3, b: Vec3, t: number) {
+ const dot = clamp(Vec3.dot(a, b), -1, 1);
+ const theta = Math.acos(dot) * t;
+ Vec3.scaleAndAdd(slerpRelVec, b, a, -dot);
+ Vec3.normalize(slerpRelVec, slerpRelVec);
+ return Vec3.add(out, Vec3.scale(out, a, Math.cos(theta)), Vec3.scale(slerpRelVec, slerpRelVec, Math.sin(theta)));
+ }
+
/**
* Performs a hermite interpolation with two control points
*/
@@ -368,6 +378,24 @@ namespace Vec3 {
}
}
+ /**
+ * Returns whether or not the vectors have exactly the same elements in the same position (when compared with ===)
+ */
+ export function exactEquals(a: Vec3, b: Vec3) {
+ return a[0] === b[0] && a[1] === b[1] && a[2] === b[2];
+ }
+
+ /**
+ * Returns whether or not the vectors have approximately the same elements in the same position.
+ */
+ export function equals(a: Vec3, b: Vec3) {
+ const a0 = a[0], a1 = a[1], a2 = a[2];
+ const b0 = b[0], b1 = b[1], b2 = b[2];
+ return (Math.abs(a0 - b0) <= EPSILON.Value * Math.max(1.0, Math.abs(a0), Math.abs(b0)) &&
+ Math.abs(a1 - b1) <= EPSILON.Value * Math.max(1.0, Math.abs(a1), Math.abs(b1)) &&
+ Math.abs(a2 - b2) <= EPSILON.Value * Math.max(1.0, Math.abs(a2), Math.abs(b2)));
+ }
+
const rotTemp = zero();
export function makeRotation(mat: Mat4, a: Vec3, b: Vec3): Mat4 {
const by = angle(a, b);
--
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