OfflineBufferProcesses.cpp

// BufRev, an NRT buffer samples swapper
// Pierre Alexandre Tremblay, 2018
// A digital debris of the FluCoMa project, funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 725899)

#include "SC_PlugIn.h"

static InterfaceTable *ft;

void BufRev(World *world, struct SndBuf *buf, struct sc_msg_iter *msg)
{
	float *data = buf->data;
	int size = buf->samples;
	int chans = buf->channels;
	int frames = buf->frames;
	int halfframe = frames/2;
	float temp;
	int loadd,hiadd;

	for (int i = 0; i < halfframe; ++i) {
		for (int j = 0; j < chans; ++j) {
			hiadd = j+size-((i+1)*chans);
			loadd = j+(i*chans);
			temp = data[hiadd];
			data[hiadd] = data[loadd];
			data[loadd] = temp;
		}
	}
}

void BufAdd(World *world, struct SndBuf *buf, struct sc_msg_iter *msg)
{
	float *data = buf->data;
	int size = buf->samples;
	float offset = msg->getf(0.0);

	for (int i = 0; i < size; ++i)
	data[i] += offset;
}

void BufGain(World *world, struct SndBuf *buf, struct sc_msg_iter *msg)
{
	float *data = buf->data;
	int size = buf->samples;
	float gain = msg->getf(-1.0);

	for (int i = 0; i < size; ++i)
	data[i] *= gain;
}

void BufRemoveDC(World *world, struct SndBuf *buf, struct sc_msg_iter *msg)
{
	float *data = buf->data;
	int chans = buf->channels;
	int frames = buf->frames;
	float coeff = msg->getf(0.995);
	float previn, in;
	double prevout, out;

	for (int j = 0; j < chans; ++j) {
		previn = data[j];
		prevout = previn;
		for (int i = 1; i < frames; ++i) {
			in = data[(i*chans)+j];
			out = in - previn + coeff * prevout;
			data[(i*chans)+j] = out;
			prevout = out;
			previn = in;
		}
	}
}

void BufChunkSwap(World *world, struct SndBuf *buf, struct sc_msg_iter *msg)
{
	float *data = buf->data;
	int chans = buf->channels;
	int frames = buf->frames;

	// reading the arguments with default values
	int srcStartAt = msg->geti(0);
	int dstStartAt = msg->geti(-1);
	int numFrames = msg->geti(0);

	// should default value happen, retrieve them
	if (dstStartAt == -1)
	dstStartAt = frames - 1; // defaults to last sample
	if (numFrames == 0)
	numFrames = (frames * -1) / 2;

	// define end writing frames (inclusive) and the incrementor value
	int AbsNumFrames = std::abs(numFrames);
	int dstStep = numFrames == AbsNumFrames ? 1 : -1;
	int srcStopAt = srcStartAt + AbsNumFrames - 1;
	int dstStopAt = dstStartAt + numFrames - dstStep;

	if (srcStartAt < 0 || srcStartAt >= frames) {
		Print("chunkSwap is not happy because the source starting is outside the buffer.\n");
		return;
	}
	else if (srcStopAt < 0 || srcStopAt >= frames) {
		Print("chunkSwap is not happy because the source finishing is outside the buffer.\n");
		return;
	}
	else if (dstStartAt < 0 || dstStartAt >= frames) {
		Print("chunkSwap is not happy because the destination starting is outside the buffer.\n");
		return;
	}
	else if (dstStopAt < 0 || dstStopAt >= frames) {
		Print("chunkSwap is not happy because the destination finishing is outside the buffer.\n");
		return;
	}

	float temp;
	int srcAdd,dstAdd;

	for (int i = srcStartAt; i <= srcStopAt; ++i) {
		for (int j = 0; j < chans; ++j) {
			dstAdd = j+(dstStartAt*chans);
			srcAdd = j+(i*chans);
			// Print("%d %d %d %d\n", i, j, hiadd, loadd);
			temp = data[dstAdd];
			data[dstAdd] = data[srcAdd];
			data[srcAdd] = temp;
		}
		dstStartAt+= dstStep;
	}
}

void BufWaveSetCopyTo(World *world, struct SndBuf *buf, struct sc_msg_iter *msg)
{
	int frames1 = buf->frames;
	int channels1 = buf->channels;

	uint32 bufnum2 = msg->geti();
	int repetitions = msg->geti();

	if (bufnum2 >= world->mNumSndBufs){
		Print("waveSetCopyTo is not happy because the source buffer does not exist.\n");
		return;
	}

	SndBuf* buf2 = world->mSndBufs + bufnum2;

	if (buf2->data == buf->data){
		Print("waveSetCopyTo is not happy because the source buffer is the same as the destination buffer.\n");
		return;
	}

	int frames2 = buf2->frames;
	int channels2 = buf2->channels;

	if (channels1 != channels2) {
		Print("waveSetCopyTo is not happy because the source buffer has a different channel count than the destination buffer.\n");
		return;
	}

	// checks if default value (0) or error in quantity and sets to a filling behaviour or at least one
	if (repetitions < 1){
		repetitions = int(frames1 / frames2);
		if (repetitions < 1)
		repetitions = 1;
	}

	//for each channels
	for (int j=0;j<channels2;j++){
		long lastXadd = -1; //set start frame as invalid address flag
		short prevpol = (buf2->data[j] > 0); //set the previous sample polarity as the first sample
		long writeindex = 0; // set the writing index at the start of the buffer
		long wavesetlenght;

		//interates through the source samples
		for (int i=0;i<frames2;i++){
			//if previously positive...
			if (prevpol){
				// Print("in1\n");
				//... and currently negative ...
				if (buf2->data[(i*channels2)+j] < 0.0) {
					// Print("in1-1\n");
					// ... flag as being now in negativeland and exit.
					prevpol = 0;
				}
			} else {
				// if previously in negativeland...
				// Print("in2\n");
				if (buf2->data[(i*channels2)+j] >= 0.0) {
					// ...and now being zero or up, so we write
					// Print("in2-2\n");
					// check it is not the first zero crossing
					if (lastXadd >=0) {
						// check if the lenght will be too long for all repetitions
						wavesetlenght = i - lastXadd;
						if (((wavesetlenght*repetitions)+ writeindex) > frames1) break;

						// write if enough place
						for (int k = 0; k < repetitions; k++){
							for (int l = 0; l < wavesetlenght; l++) {
								buf->data[(writeindex*channels2)+j] = buf2->data[((lastXadd+l)*channels2)+j];
								writeindex++;
							}
						}
					}
					// setting the flag and the new past
					prevpol = 1;
					lastXadd = i;
				}
			}
		}
	}
}

PluginLoad(OfflineBufferProcessesUGens) {
	ft = inTable;
	DefineBufGen("mul", BufGain);
	DefineBufGen("add", BufAdd);
	DefineBufGen("reverse", BufRev);
	DefineBufGen("removeDC", BufRemoveDC);
	DefineBufGen("chunkSwap", BufChunkSwap);
	DefineBufGen("waveSetCopyTo", BufWaveSetCopyTo);
}