47 lines
1.3 KiB
Rust
47 lines
1.3 KiB
Rust
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// nih-plug: plugins, but rewritten in Rust
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// Copyright (C) 2022 Robbert van der Helm
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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pub const MINUS_INFINITY_DB: f32 = -100.0;
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/// Convert decibels to gain, treating anything below -100 dB as minus infinity.
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pub fn db_to_gain(dbs: f32) -> f32 {
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if dbs > MINUS_INFINITY_DB {
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10.0f32.powf(dbs * 0.05)
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} else {
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0.0
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_db_to_gain_positive() {
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assert_eq!(db_to_gain(3.0), 1.4125376);
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}
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#[test]
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fn test_db_to_gain_negative() {
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assert_eq!(db_to_gain(-3.0), 1.4125376f32.recip());
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}
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#[test]
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fn test_db_to_gain_minus_infinity() {
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assert_eq!(db_to_gain(-100.0), 0.0);
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}
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}
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