input.test.ts

1	import { describe, expect, it } from 'vitest'
2	import { padSteer, tiltSteer } from '../src/input.js'
3
4	describe('steering by tilt', () => {
5	it('is nothing for a phone held level, or nearly', () => {
6	for (const roll of [0, 2, -3.9, 4]) expect(tiltSteer(40, roll, 0)).toBe(0)
7	})
8
9	it('steers the way the phone is leaned, more the further, and no more than fully', () => {
10	expect(tiltSteer(40, 10, 0)).toBeCloseTo(0.25, 5)
11	expect(tiltSteer(40, 16, 0)).toBeCloseTo(0.5, 5)
12	expect(tiltSteer(40, -16, 0)).toBeCloseTo(-0.5, 5)
13	expect(tiltSteer(40, 28, 0)).toBe(1)
14	expect(tiltSteer(40, 75, 0)).toBe(1)
15	expect(tiltSteer(40, -75, 0)).toBe(-1)
16	})
17
18	it('takes no notice of how far back the phone is tipped, held upright', () => {
19	for (const tip of [0, 30, 60, 85]) expect(tiltSteer(tip, 16, 0)).toBeCloseTo(0.5, 5)
20	})
21
22	it('held on its side, steers by what was its tip, whichever side is up', () => {
23	// Top edge to the left: leaning right is the top edge rising.
24	expect(tiltSteer(16, 0, 90)).toBeCloseTo(0.5, 5)
25	expect(tiltSteer(-16, 0, 90)).toBeCloseTo(-0.5, 5)
26	// Top edge to the right: the other way about.
27	expect(tiltSteer(16, 0, 270)).toBeCloseTo(-0.5, 5)
28	// And upside down, the roll is reversed.
29	expect(tiltSteer(0, 16, 180)).toBeCloseTo(-0.5, 5)
30	})
31	})
32
33	describe('steering by a controller', () => {
34	it('is nothing for a stick at rest, which is never quite at its middle', () => {
35	for (const lean of [0, 0.05, -0.12, 0.15]) expect(padSteer(lean)).toBe(0)
36	})
37
38	it('eases in from there to full steering with the stick right over', () => {
39	expect(padSteer(0.575)).toBeCloseTo(0.5, 5)
40	expect(padSteer(-0.575)).toBeCloseTo(-0.5, 5)
41	expect(padSteer(1)).toBe(1)
42	expect(padSteer(-1)).toBe(-1)
43	})
44	})