| // Copyright 2021 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| /// Rounds the given volume level to the nearest 1%. Input should be a float between 0.0 and 1.0 and |
| /// the result will also be clamped to this range. |
| /// |
| /// Rounding should be applied to audio levels handled by settings service that come from external |
| /// sources. |
| pub fn round_volume_level(volume: f32) -> f32 { |
| return ((volume * 100.0).round() / 100.0).max(0.0).min(1.0); |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::round_volume_level; |
| |
| /// Various tests to verify rounding works as expected. |
| #[test] |
| fn test_round_volume() { |
| assert_eq!(round_volume_level(1.0), 1.0); |
| assert_eq!(round_volume_level(0.0), 0.0); |
| assert_eq!(round_volume_level(0.222222), 0.22); |
| assert_eq!(round_volume_level(0.349), 0.35); |
| assert_eq!(round_volume_level(0.995), 1.0); |
| assert_eq!(round_volume_level(0.994), 0.99); |
| } |
| |
| /// Verifies that values below 0.0 round to 0.0. |
| #[test] |
| fn test_round_volume_below_range() { |
| assert_eq!(round_volume_level(-1.0), 0.0); |
| assert_eq!(round_volume_level(-0.1), 0.0); |
| assert_eq!(round_volume_level(-0.0), 0.0); |
| assert_eq!(round_volume_level(std::f32::MIN), 0.0); |
| } |
| |
| /// Verifies that values above 1.0 round to 1.0. |
| #[test] |
| fn test_round_volume_above_range() { |
| assert_eq!(round_volume_level(2.0), 1.0); |
| assert_eq!(round_volume_level(1.1), 1.0); |
| assert_eq!(round_volume_level(std::f32::MAX), 1.0); |
| } |
| } |
