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ADDED: Audio stream input callback #2212 -WIP-

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WARNING: This addition is based on a PR and it's still under review, not sure if it will be maintained in the future. In general, raylib tries to avoid callbacks usage mechanisms.
This commit is contained in:
Ray 2022-03-24 20:49:11 +01:00
parent bcd84cd36d
commit 381236051f
3 changed files with 64 additions and 5 deletions
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43
examples/audio/audio_raw_stream.c
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@ -20,6 +20,35 @@
#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;
void AudioCallback(void *buffer, unsigned int frames)
{
audioFrequency = frequency + (audioFrequency - frequency)*0.95f;
audioFrequency += 1.0f;
audioFrequency -= 1.0f;
float incr = audioFrequency/44100.0f;
short *d = (short *)buffer;
for (int i = 0; i < frames; i++)
{
d[i] = (short)(32000.0f*sinf(2*PI*sineIdx));
sineIdx += incr;
if (sineIdx > 1.0f) sineIdx -= 1.0f;
}
}
int main(void)
{
// Initialization
@ -33,9 +62,11 @@ int main(void)
SetAudioStreamBufferSizeDefault(MAX_SAMPLES_PER_UPDATE);
// Init raw audio stream (sample rate: 22050, sample size: 16bit-short, channels: 1-mono)
// Init raw audio stream (sample rate: 44100, sample size: 16bit-short, channels: 1-mono)
AudioStream stream = LoadAudioStream(44100, 16, 1);
SetAudioStreamCallback(stream, &AudioCallback);
// Buffer for the single cycle waveform we are synthesizing
short *data = (short *)malloc(sizeof(short)*MAX_SAMPLES);
@ -47,6 +78,7 @@ int main(void)
// Position read in to determine next frequency
Vector2 mousePosition = { -100.0f, -100.0f };
/*
// Cycles per second (hz)
float frequency = 440.0f;
@ -55,6 +87,7 @@ int main(void)
// 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;
@ -82,7 +115,7 @@ int main(void)
SetAudioStreamPan(stream, pan);
}
// Rewrite the sine wave.
// Rewrite the sine wave
// Compute two cycles to allow the buffer padding, simplifying any modulation, resampling, etc.
if (frequency != oldFrequency)
{
@ -92,17 +125,18 @@ int main(void)
if (waveLength > MAX_SAMPLES/2) waveLength = MAX_SAMPLES/2;
if (waveLength < 1) waveLength = 1;
// Write sine wave.
// Write sine wave
for (int i = 0; i < waveLength*2; i++)
{
data[i] = (short)(sinf(((2*PI*(float)i/waveLength)))*32000);
}
// Scale read cursor's position to minimize transition artifacts
readCursor = (int)(readCursor * ((float)waveLength / (float)oldWavelength));
//readCursor = (int)(readCursor * ((float)waveLength / (float)oldWavelength));
oldFrequency = frequency;
}
/*
// Refill audio stream if required
if (IsAudioStreamProcessed(stream))
{
@ -131,6 +165,7 @@ int main(void)
// Copy finished frame to audio stream
UpdateAudioStream(stream, writeBuf, MAX_SAMPLES_PER_UPDATE);
}
*/
//----------------------------------------------------------------------------------
// Draw