mirror of
https://github.com/RGBCube/serenity
synced 2025-10-30 23:52:43 +00:00
76b71fcb75
This was a rather easy change, since only parameter names make use of strings in the first place. This also improves OOM resistance: If we can't create a parameter name, we will just set it to the empty string.
70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
/*
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* Copyright (c) 2021, Arne Elster <arne@elster.li>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/FixedArray.h>
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#include <AK/Math.h>
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namespace DSP {
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template<typename T>
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class Window final {
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public:
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template<size_t size>
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constexpr static Array<T, size> hamming() { return make_window<size>(calculate_hamming); }
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constexpr static FixedArray<T> hamming(size_t size) { return make_window(size, calculate_hamming); }
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template<size_t size>
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constexpr static Array<T, size> hann() { return make_window<size>(calculate_hann); }
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constexpr static FixedArray<T> hann(size_t size) { return make_window(size, calculate_hann); }
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template<size_t size>
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constexpr static Array<T, size> blackman_harris() { return make_window<size>(calculate_blackman_harris); }
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constexpr static FixedArray<T> blackman_harris(size_t size) { return make_window(size, calculate_blackman_harris); }
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private:
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constexpr static float calculate_hann(size_t index, size_t size)
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{
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return 0.5f * (1 - AK::cos<float>((2 * AK::Pi<T> * index) / (size - 1)));
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}
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constexpr static float calculate_hamming(size_t index, size_t size)
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{
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return 0.54f - 0.46f * AK::cos<float>((2 * AK::Pi<T> * index) / (size - 1));
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}
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constexpr static float calculate_blackman_harris(size_t index, size_t size)
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{
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T const a0 = 0.35875;
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T const a1 = 0.48829;
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T const a2 = 0.14128;
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T const a3 = 0.01168;
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return a0 - a1 * AK::cos(2 * AK::Pi<T> * index / size) + a2 * AK::cos(4 * AK::Pi<T> * index / size) - a3 * AK::cos(6 * AK::Pi<T> * index / size);
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}
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template<size_t size>
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constexpr static Array<T, size> make_window(auto window_function)
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{
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Array<T, size> result;
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for (size_t i = 0; i < size; i++) {
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result[i] = window_function(i, size);
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}
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return result;
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}
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constexpr static FixedArray<T> make_window(size_t size, auto window_function)
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{
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FixedArray<T> result;
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result.resize(size);
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for (size_t i = 0; i < size; i++) {
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result[i] = window_function(i, size);
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}
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return result;
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}
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};
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}
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