64 lines
1.8 KiB
C++
64 lines
1.8 KiB
C++
/*
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* fold.h
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* Copyright (c) 2025 Christopher Herb
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#pragma once
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namespace trnr {
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// folds the wave from -1 to 1
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inline float fold(float& sample)
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{
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while (sample > 1.0 || sample < -1.0) {
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if (sample > 1.0) {
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sample = 2.0 - sample;
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} else if (sample < -1.0) {
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sample = -2.0 - sample;
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}
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}
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return sample;
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}
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// folds the positive part of the wave independently from the negative part.
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inline float fold_bipolar(float& sample)
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{
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// fold positive values
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if (sample > 1.0) {
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sample = 2.0 - sample;
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if (sample < 0.0) { sample = -sample; }
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return fold(sample);
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}
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// fold negative values
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else if (sample < -1.0) {
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sample = -2.0 - sample;
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if (sample > 0.0) { sample = -sample; }
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return fold(sample);
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} else {
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return sample;
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}
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}
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}; // namespace trnr
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