Archivist
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raylib-src
дзеркало https://github.com/raysan5/raylib


								/*******************************************************************************************

								*

								*   raylib [audio] example - Music stream processing effects

								*

								*   Example originally created with raylib 4.2, last time updated with raylib 5.0

								*

								*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,

								*   BSD-like license that allows static linking with closed source software

								*

								*   Copyright (c) 2022-2024 Ramon Santamaria (@raysan5)

								*

								********************************************************************************************/


								#include "raylib.h"


								#include <stdlib.h> // Required for: NULL


								// Required delay effect variables

								static float *delayBuffer = NULL;

								static unsigned int delayBufferSize = 0;

								static unsigned int delayReadIndex = 2;

								static unsigned int delayWriteIndex = 0;


								//------------------------------------------------------------------------------------

								// Module Functions Declaration

								//------------------------------------------------------------------------------------

								static void AudioProcessEffectLPF(void *buffer, unsigned int frames);   // Audio effect: lowpass filter

								static void AudioProcessEffectDelay(void *buffer, unsigned int frames); // Audio effect: delay


								//------------------------------------------------------------------------------------

								// Program main entry point

								//------------------------------------------------------------------------------------

								int main(void)

								{

								    // Initialization

								    //--------------------------------------------------------------------------------------

								    const int screenWidth = 800;

								    const int screenHeight = 450;


								    InitWindow(screenWidth, screenHeight, "raylib [audio] example - stream effects");


								    InitAudioDevice();              // Initialize audio device


								    Music music = LoadMusicStream("resources/country.mp3");


								    // Allocate buffer for the delay effect

								    delayBufferSize = 48000*2;      // 1 second delay (device sampleRate*channels)

								    delayBuffer = (float *)RL_CALLOC(delayBufferSize, sizeof(float));


								    PlayMusicStream(music);


								    float timePlayed = 0.0f;        // Time played normalized [0.0f..1.0f]

								    bool pause = false;             // Music playing paused


								    bool enableEffectLPF = false;   // Enable effect low-pass-filter

								    bool enableEffectDelay = false; // Enable effect delay (1 second)


								    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second

								    //--------------------------------------------------------------------------------------


								    // Main game loop

								    while (!WindowShouldClose())    // Detect window close button or ESC key

								    {

								        // Update

								        //----------------------------------------------------------------------------------

								        UpdateMusicStream(music);   // Update music buffer with new stream data


								        // Restart music playing (stop and play)

								        if (IsKeyPressed(KEY_SPACE))

								        {

								            StopMusicStream(music);

								            PlayMusicStream(music);

								        }


								        // Pause/Resume music playing

								        if (IsKeyPressed(KEY_P))

								        {

								            pause = !pause;


								            if (pause) PauseMusicStream(music);

								            else ResumeMusicStream(music);

								        }


								        // Add/Remove effect: lowpass filter

								        if (IsKeyPressed(KEY_F))

								        {

								            enableEffectLPF = !enableEffectLPF;

								            if (enableEffectLPF) AttachAudioStreamProcessor(music.stream, AudioProcessEffectLPF);

								            else DetachAudioStreamProcessor(music.stream, AudioProcessEffectLPF);

								        }


								        // Add/Remove effect: delay

								        if (IsKeyPressed(KEY_D))

								        {

								            enableEffectDelay = !enableEffectDelay;

								            if (enableEffectDelay) AttachAudioStreamProcessor(music.stream, AudioProcessEffectDelay);

								            else DetachAudioStreamProcessor(music.stream, AudioProcessEffectDelay);

								        }


								        // Get normalized time played for current music stream

								        timePlayed = GetMusicTimePlayed(music)/GetMusicTimeLength(music);


								        if (timePlayed > 1.0f) timePlayed = 1.0f;   // Make sure time played is no longer than music

								        //----------------------------------------------------------------------------------


								        // Draw

								        //----------------------------------------------------------------------------------

								        BeginDrawing();


								            ClearBackground(RAYWHITE);


								            DrawText("MUSIC SHOULD BE PLAYING!", 245, 150, 20, LIGHTGRAY);


								            DrawRectangle(200, 180, 400, 12, LIGHTGRAY);

								            DrawRectangle(200, 180, (int)(timePlayed*400.0f), 12, MAROON);

								            DrawRectangleLines(200, 180, 400, 12, GRAY);


								            DrawText("PRESS SPACE TO RESTART MUSIC", 215, 230, 20, LIGHTGRAY);

								            DrawText("PRESS P TO PAUSE/RESUME MUSIC", 208, 260, 20, LIGHTGRAY);


								            DrawText(TextFormat("PRESS F TO TOGGLE LPF EFFECT: %s", enableEffectLPF? "ON" : "OFF"), 200, 320, 20, GRAY);

								            DrawText(TextFormat("PRESS D TO TOGGLE DELAY EFFECT: %s", enableEffectDelay? "ON" : "OFF"), 180, 350, 20, GRAY);


								        EndDrawing();

								        //----------------------------------------------------------------------------------

								    }


								    // De-Initialization

								    //--------------------------------------------------------------------------------------

								    UnloadMusicStream(music);   // Unload music stream buffers from RAM


								    CloseAudioDevice();         // Close audio device (music streaming is automatically stopped)


								    RL_FREE(delayBuffer);       // Free delay buffer


								    CloseWindow();              // Close window and OpenGL context

								    //--------------------------------------------------------------------------------------


								    return 0;

								}


								//------------------------------------------------------------------------------------

								// Module Functions Definition

								//------------------------------------------------------------------------------------

								// Audio effect: lowpass filter

								static void AudioProcessEffectLPF(void *buffer, unsigned int frames)

								{

								    static float low[2] = { 0.0f, 0.0f };

								    static const float cutoff = 70.0f / 44100.0f; // 70 Hz lowpass filter

								    const float k = cutoff / (cutoff + 0.1591549431f); // RC filter formula


								    // Converts the buffer data before using it

								    float *bufferData = (float *)buffer;

								    for (unsigned int i = 0; i < frames*2; i += 2)

								    {

								        const float l = bufferData[i];

								        const float r = bufferData[i + 1];


								        low[0] += k * (l - low[0]);

								        low[1] += k * (r - low[1]);

								        bufferData[i] = low[0];

								        bufferData[i + 1] = low[1];

								    }

								}


								// Audio effect: delay

								static void AudioProcessEffectDelay(void *buffer, unsigned int frames)

								{

								    for (unsigned int i = 0; i < frames*2; i += 2)

								    {

								        float leftDelay = delayBuffer[delayReadIndex++];    // ERROR: Reading buffer -> WHY??? Maybe thread related???

								        float rightDelay = delayBuffer[delayReadIndex++];


								        if (delayReadIndex == delayBufferSize) delayReadIndex = 0;


								        ((float *)buffer)[i] = 0.5f*((float *)buffer)[i] + 0.5f*leftDelay;

								        ((float *)buffer)[i + 1] = 0.5f*((float *)buffer)[i + 1] + 0.5f*rightDelay;


								        delayBuffer[delayWriteIndex++] = ((float *)buffer)[i];

								        delayBuffer[delayWriteIndex++] = ((float *)buffer)[i + 1];

								        if (delayWriteIndex == delayBufferSize) delayWriteIndex = 0;

								    }

								}