Cross-Correlation of Two Signals (DI and Microphone) - c++

Question

I'm wondering if anyone would possibly be able to give me some advice on how to implement a cross-correlation function within two simple delay lines that I have set up. My problem is that I have two hard coded delay lines that I can manually change to align two signals going in. I'm using a DI signal and a microphone signal from a bass amp. If I use this code in its current state it will delay the DI signal, but what I want it to do, is take the two signals and align them within the DSP for it to output them in phase with one and other. My current code can be seen below:
#include <Bela.h>
#define DELAY_BUFFER_SIZE 44100
// Buffer holding previous samples per channel
float gDelayBuffer_l[DELAY_BUFFER_SIZE] = {0};
float gDelayBuffer_r[DELAY_BUFFER_SIZE] = {0};
// Write pointer
int gDelayBufWritePtr = 0;
// Amount of delay
float gDelayAmount = 1;
// Amount of feedback
float gDelayFeedbackAmount = 0;
// Level of pre-delay input
float gDelayAmountPre = 1;
// Amount of delay in samples
int gDelayInSamples = 22050;
// Buffer holding previous samples per channel
float hDelayBuffer_l[DELAY_BUFFER_SIZE] = {0};
float hDelayBuffer_r[DELAY_BUFFER_SIZE] = {0};
// Write pointer
int hDelayBufWritePtr = 0;
// Amount of delay
float hDelayAmount = 1;
// Amount of feedback
float hDelayFeedbackAmount = 0;
// Level of pre-delay input
float hDelayAmountPre = 1;
// Amount of delay in samples
int hDelayInSamples = 44100;
bool setup(BelaContext *context, void *userData)
{
return true;
}
void render(BelaContext *context, void *userData)
{
for(unsigned int n = 0; n < context->analogFrames; n++) {
float out_l = 0;
float out_r = 0;
// Read audio inputs
out_l = analogRead(context,n,0);
out_r = analogRead(context,n,1);
// Increment delay buffer write pointer
if(++gDelayBufWritePtr>DELAY_BUFFER_SIZE)
gDelayBufWritePtr = 0;
// Increment delay buffer write pointer
// Calculate the sample that will be written into the delay buffer...
// 1. Multiply the current (dry) sample by the pre-delay gain level (set above)
// 2. Get the previously delayed sample from the buffer, multiply it by the feedback gain and add it to the current sample
float del_input_l = (gDelayAmountPre * out_l + gDelayBuffer_l[(gDelayBufWritePtr-gDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * gDelayFeedbackAmount);
float del_input_r = (gDelayAmountPre * out_r + gDelayBuffer_r[(gDelayBufWritePtr-gDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * gDelayFeedbackAmount);
// Now we can write it into the delay buffer
gDelayBuffer_l[gDelayBufWritePtr] = del_input_l;
gDelayBuffer_r[gDelayBufWritePtr] = del_input_r;
// Get the delayed sample (by reading `gDelayInSamples` many samples behind our current write pointer) and add it to our output sample
out_l = gDelayBuffer_l[(gDelayBufWritePtr-gDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * gDelayAmount;
out_r = gDelayBuffer_r[(gDelayBufWritePtr-gDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * gDelayAmount;
// Write the sample into the output buffer
analogWrite(context, n, 0, out_l);
analogWrite(context, n, 1, out_r);
}
for(unsigned int n = 0; n < context->analogFrames; n++) {
float out_l = 0;
float out_r = 0;
// Read audio inputs
out_l = analogRead(context,n,2);
out_r = analogRead(context,n,3);
// Increment delay buffer write pointer
if(++hDelayBufWritePtr>DELAY_BUFFER_SIZE)
hDelayBufWritePtr = 0;
// Increment delay buffer write pointer
if(++hDelayBufWritePtr>DELAY_BUFFER_SIZE)
hDelayBufWritePtr = 0;
// Calculate the sample that will be written into the delay buffer...
// 1. Multiply the current (dry) sample by the pre-delay gain level (set above)
// 2. Get the previously delayed sample from the buffer, multiply it by the feedback gain and add it to the current sample
float del_input_l = (hDelayAmountPre * out_l + hDelayBuffer_l[(hDelayBufWritePtr-hDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * hDelayFeedbackAmount);
float del_input_r = (hDelayAmountPre * out_r + hDelayBuffer_r[(hDelayBufWritePtr-hDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * hDelayFeedbackAmount);
// Now we can write it into the delay buffer
hDelayBuffer_l[hDelayBufWritePtr] = del_input_l;
hDelayBuffer_r[hDelayBufWritePtr] = del_input_r;
// Get the delayed sample (by reading `gDelayInSamples` many samples behind our current write pointer) and add it to our output sample
out_l = hDelayBuffer_l[(hDelayBufWritePtr-hDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * hDelayAmount;
out_r = hDelayBuffer_r[(hDelayBufWritePtr-hDelayInSamples+DELAY_BUFFER_SIZE)%DELAY_BUFFER_SIZE] * hDelayAmount;
// Write the sample into the output buffer
analogWrite(context, n, 2, out_l);
analogWrite(context, n, 3, out_r);
}
}
void cleanup(BelaContext *context, void *userData)
{
}