sample_arithmetic.h

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/*
    Beatmup image and signal processing library
    Copyright (C) 2019, lnstadrum
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#pragma once
#include "../basic_types.h"
#include "../utils/utils.hpp"
 
namespace Beatmup {
 
    /**
        Format of audio samples
    */
    enum AudioSampleFormat {
        Int8,       //!< signed integer, 8 bit per sample
        Int16,      //!< signed integer, 16 bit per sample
        Int32,      //!< signed integer, 32 bit per sample
        Float32     //!< floating point, 32 bit per sample
    };
 
    const int AUDIO_SAMPLE_SIZE[] = { 1, 2, 3, 4 };
    const char* const AUDIO_FORMAT_NAME[] = { "8 bit", "16 bit", "32 bit", "32 bit float" };
 
    struct sample8;
    struct sample16;
    struct sample32;
    struct sample32f;
 
    struct sample8 {
        signed char x;
        inline bool operator < (const sample8& sample) const { return x < sample.x; }
        operator sample16() const;
        operator sample32() const;
        operator sample32f() const;
        void operator =(const sample16 S);
        void operator =(const sample32 S);
        void operator =(const sample32f S);
        static const int
            MIN_VALUE = -128,
            MAX_VALUE = +127;
    };
 
    struct sample16 {
        signed short int x;
        inline bool operator < (const sample16& sample) const { return x < sample.x; }
        operator sample8() const;
        operator sample32() const;
        operator sample32f() const;
        void operator =(const sample8 S);
        void operator =(const sample32 S);
        void operator =(const sample32f S);
        static const int
            MIN_VALUE = -32768,
            MAX_VALUE = +32767;
    };
 
    struct sample32 {
        int x;
        inline bool operator < (const sample32& sample) const { return x < sample.x; }
        operator sample8() const;
        operator sample16() const;
        operator sample32f() const;
        void operator =(const sample8 S);
        void operator =(const sample16 S);
        void operator =(const sample32f S);
        static const long
            MIN_VALUE = -2147483647-1,
            MAX_VALUE = +2147483647;
    };
 
    struct sample32f {
        float x;
        inline bool operator < (const sample32f& sample) const { return x < sample.x; }
        operator sample8() const;
        operator sample16() const;
        operator sample32() const;
        void operator =(const sample8 S);
        void operator =(const sample16 S);
        void operator =(const sample32 S);
        static const float
            MIN_VALUE,
            MAX_VALUE;
    };
 
    //////////////////////////////////////////////////////////////
    //                      8 bit integer                       //
    //////////////////////////////////////////////////////////////
    
    inline sample8::operator sample16() const {
        return sample16{ (decltype(sample16::x)) (x << 8) };
    }
 
    inline sample8::operator sample32() const {
        return sample32{ x << 2 };
    }
 
    inline sample8::operator sample32f() const {
        return sample32f{ x / 127.0f };
    }
 
    inline void sample8::operator =(const sample16 S) {
        x = (decltype(x))( S.x >> 8 );
    }
 
    inline void sample8::operator =(const sample32 S) {
        x = (decltype(x))( S.x >> 24 );
    }
 
    inline void sample8::operator =(const sample32f S) {
        x = (decltype(x)) roundf_fast(S.x * 127);
    }
 
 
    //////////////////////////////////////////////////////////////
    //                      16 bit integer                      //
    //////////////////////////////////////////////////////////////
    
    inline sample16::operator sample8() const {
        return sample8{ (decltype(sample8::x))( x >> 8 ) };
    }
 
    inline sample16::operator sample32() const {
        return sample32{ x << 16 };
    }
 
    inline sample16::operator sample32f() const {
        return sample32f{ x / 32767.0f };
    }
 
    inline void sample16::operator =(const sample8 S) {
        x = S.x << 8;
    }
    
    inline void sample16::operator =(const sample32 S) {
        x = (decltype(x))( S.x >> 8 );
    }
 
    inline void sample16::operator =(const sample32f S) {
        x = (decltype(x)) roundf_fast(S.x * 32767);
    }
 
    //////////////////////////////////////////////////////////////
    //                      32 bit integer                      //
    //////////////////////////////////////////////////////////////
    
    inline sample32::operator sample8() const {
        return sample8{ (decltype(sample8::x)) (x >> 24) };
    }
 
    inline sample32::operator sample16() const {
        return sample16{ (decltype(sample16::x)) (x >> 16) };
    }
 
    inline sample32::operator sample32f() const {
        return sample32f{ x / 2147483647.0f };
    }
 
    inline void sample32::operator =(const sample8 S) {
        x = S.x << 24;
    }
 
    inline void sample32::operator =(const sample16 S) {
        x = S.x << 16;
    }
 
    inline void sample32::operator =(const sample32f S) {
        x = roundf_fast(S.x * 2147483647);
    }
 
    //////////////////////////////////////////////////////////////
    //                      32 bit float                        //
    //////////////////////////////////////////////////////////////
    
    inline sample32f::operator sample8() const {
        return sample8{ (decltype(sample8::x)) roundf_fast(x *127) };
    }
 
    inline sample32f::operator sample16() const {
        return sample16{ (decltype(sample16::x)) roundf_fast(x * 32767) };
    }
 
    inline sample32f::operator sample32() const {
        return sample32{ roundf_fast(x * 2147483647) };
    }
 
    inline void sample32f::operator =(const sample8 S) {
        x = S.x / 128.0f;
    }
 
    inline void sample32f::operator =(const sample16 S) {
        x = S.x / 32768.0f;
    }
 
    inline void sample32f::operator =(const sample32 S) {
        x = S.x / 2147483648.0f;
    }
 
    //////////////////////////////////////////////////////////////
    //                      Miscellaneous                       //
    //////////////////////////////////////////////////////////////
 
    inline bool operator!=(const sample16& A, const sample16& B) {
        return A.x != B.x;
    }
 
 
    template<typename in, typename out> void convertSamples(in* const input, void* output, msize count) {
        const in* stop = input + count;
        out* po = (out*)output;
        for (const in* pi = input; pi < stop; pi++, po++)
            *po = *pi;
    }
}