28 lines
811 B
TypeScript
28 lines
811 B
TypeScript
import { expect, test } from "vitest";
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import { vec } from "./given.ts";
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import { dot, length, normalize } from "./mathv.ts";
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test("length uses Pythagoras", () => {
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expect(length(vec(3, 4))).toBe(5);
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expect(length(vec(0, 0))).toBe(0);
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});
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test("normalize gives a unit vector in the same direction", () => {
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const n = normalize(vec(3, 4));
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expect(n.x).toBeCloseTo(0.6);
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expect(n.y).toBeCloseTo(0.8);
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expect(length(n)).toBeCloseTo(1);
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});
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test("normalize of the zero vector is (0,0), not NaN", () => {
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const n = normalize(vec(0, 0));
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expect(n).toEqual({ x: 0, y: 0 });
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expect(Number.isNaN(n.x)).toBe(false);
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expect(Number.isNaN(n.y)).toBe(false);
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});
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test("dot product", () => {
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expect(dot(vec(1, 0), vec(0, 1))).toBe(0); // perpendicular
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expect(dot(vec(2, 3), vec(4, 5))).toBe(23); // 8 + 15
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});
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