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audio_raw_stream.c
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214 lines (164 loc) · 7.57 KB
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/*******************************************************************************************
*
* raylib [audio] example - raw stream
*
* Example complexity rating: [★★★☆] 3/4
*
* Example originally created with raylib 1.6, last time updated with raylib 4.2
*
* Example created by Ramon Santamaria (@raysan5) and reviewed by James Hofmann (@triplefox)
*
* 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) 2015-2025 Ramon Santamaria (@raysan5) and James Hofmann (@triplefox)
*
********************************************************************************************/
#include "raylib.h"
#include <stdlib.h> // Required for: malloc(), free()
#include <math.h> // Required for: sinf()
#include <string.h> // Required for: memcpy()
#define MAX_SAMPLES 512
#define MAX_SAMPLES_PER_UPDATE 4096
// Cycles per second (hz)
float frequency = 440.0f;
// Audio frequency, for smoothing
float audioFrequency = 440.0f;
// Previous value, used to test if sine needs to be rewritten, and to smoothly modulate frequency
float oldFrequency = 1.0f;
// Index for audio rendering
float sineIdx = 0.0f;
// Audio input processing callback
void AudioInputCallback(void *buffer, unsigned int frames)
{
audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
float incr = audioFrequency/44100.0f;
short *d = (short *)buffer;
for (unsigned int i = 0; i < frames; i++)
{
d[i] = (short)(32000.0f*sinf(2*PI*sineIdx));
sineIdx += incr;
if (sineIdx > 1.0f) sineIdx -= 1.0f;
}
}
//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib [audio] example - raw stream");
InitAudioDevice(); // Initialize audio device
SetAudioStreamBufferSizeDefault(MAX_SAMPLES_PER_UPDATE);
// Init raw audio stream (sample rate: 44100, sample size: 16bit-short, channels: 1-mono)
AudioStream stream = LoadAudioStream(44100, 16, 1);
SetAudioStreamCallback(stream, AudioInputCallback);
// Buffer for the single cycle waveform we are synthesizing
short *data = (short *)malloc(sizeof(short)*MAX_SAMPLES);
// Frame buffer, describing the waveform when repeated over the course of a frame
short *writeBuf = (short *)malloc(sizeof(short)*MAX_SAMPLES_PER_UPDATE);
PlayAudioStream(stream); // Start processing stream buffer (no data loaded currently)
// Position read in to determine next frequency
Vector2 mousePosition = { -100.0f, -100.0f };
/*
// Cycles per second (hz)
float frequency = 440.0f;
// Previous value, used to test if sine needs to be rewritten, and to smoothly modulate frequency
float oldFrequency = 1.0f;
// Cursor to read and copy the samples of the sine wave buffer
int readCursor = 0;
*/
// Computed size in samples of the sine wave
int waveLength = 1;
Vector2 position = { 0, 0 };
SetTargetFPS(30); // Set our game to run at 30 frames-per-second
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
mousePosition = GetMousePosition();
if (IsMouseButtonDown(MOUSE_BUTTON_LEFT))
{
float fp = (float)(mousePosition.y);
frequency = 40.0f + (float)(fp);
float pan = (float)(mousePosition.x)/(float)screenWidth;
SetAudioStreamPan(stream, pan);
}
// Rewrite the sine wave
// Compute two cycles to allow the buffer padding, simplifying any modulation, resampling, etc.
if (frequency != oldFrequency)
{
// Compute wavelength. Limit size in both directions
//int oldWavelength = waveLength;
waveLength = (int)(22050/frequency);
if (waveLength > MAX_SAMPLES/2) waveLength = MAX_SAMPLES/2;
if (waveLength < 1) waveLength = 1;
// Write sine wave
for (int i = 0; i < waveLength*2; i++)
{
data[i] = (short)(sinf(((2*PI*(float)i/waveLength)))*32000);
}
// Make sure the rest of the line is flat
for (int j = waveLength*2; j < MAX_SAMPLES; j++)
{
data[j] = (short)0;
}
// Scale read cursor's position to minimize transition artifacts
//readCursor = (int)(readCursor*((float)waveLength/(float)oldWavelength));
oldFrequency = frequency;
}
/*
// Refill audio stream if required
if (IsAudioStreamProcessed(stream))
{
// Synthesize a buffer that is exactly the requested size
int writeCursor = 0;
while (writeCursor < MAX_SAMPLES_PER_UPDATE)
{
// Start by trying to write the whole chunk at once
int writeLength = MAX_SAMPLES_PER_UPDATE-writeCursor;
// Limit to the maximum readable size
int readLength = waveLength-readCursor;
if (writeLength > readLength) writeLength = readLength;
// Write the slice
memcpy(writeBuf + writeCursor, data + readCursor, writeLength*sizeof(short));
// Update cursors and loop audio
readCursor = (readCursor + writeLength)%waveLength;
writeCursor += writeLength;
}
// Copy finished frame to audio stream
UpdateAudioStream(stream, writeBuf, MAX_SAMPLES_PER_UPDATE);
}
*/
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(RAYWHITE);
DrawText(TextFormat("sine frequency: %i",(int)frequency), GetScreenWidth() - 220, 10, 20, RED);
DrawText("click mouse button to change frequency or pan", 10, 10, 20, DARKGRAY);
// Draw the current buffer state proportionate to the screen
for (int i = 0; i < screenWidth; i++)
{
position.x = (float)i;
position.y = 250 + 50*data[i*MAX_SAMPLES/screenWidth]/32000.0f;
DrawPixelV(position, RED);
}
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
free(data); // Unload sine wave data
free(writeBuf); // Unload write buffer
UnloadAudioStream(stream); // Close raw audio stream and delete buffers from RAM
CloseAudioDevice(); // Close audio device (music streaming is automatically stopped)
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}