pplugins/ptap/ptap.cpp

/*
  Copyright 2013 Peter Nelson

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <math.h>
#include <lv2.h>
#include "ptap.h"

#define BUFFER_SECONDS 10

struct PTap
{
	double sample_rate;
	size_t buffer_max;

	/* Ports */
	struct {
		float *in[NUM_CHANNELS];
		float *out[NUM_CHANNELS];
		float *matrix[NUM_GAINS][NUM_GAINS];
		float *gain[NUM_GAINS];
		float *delay[NUM_TAPS];
	} ports;

	float *buffers[NUM_TAPS];           ///< Tap audio buffers
	const float *buffers_end[NUM_TAPS]; ///< Audio buffer end points
	float *wp[NUM_TAPS];                ///< Write pointers

	PTap(double sample_rate);
	~PTap();
};

PTap::PTap(double sample_rate)
{
	this->sample_rate = sample_rate;
	this->buffer_max  = sample_rate * BUFFER_SECONDS + 1;

	for (int i = 0; i < NUM_TAPS; i++) {
		this->buffers[i] = new float[this->buffer_max]();
		this->buffers_end[i] = this->buffers[i] + this->buffer_max;
		this->wp[i] = this->buffers[i];
	}
}

PTap::~PTap()
{
	for (int i = 0; i < NUM_TAPS; i++) {
		delete[] this->buffers[i];
	}
}

static LV2_Handle ptap_instantiate(
	const LV2_Descriptor *descriptor,
	double sample_rate,
	const char *bundle_path,
	const LV2_Feature *const *host_features)
{
	/* Allocate local data */
	PTap *ptap = new PTap(sample_rate);

	return (LV2_Handle)ptap;
}

static void ptap_connect_port(LV2_Handle lv2instance, uint32_t port, void *data)
{
	PTap *ptap = (PTap *)lv2instance;
	float *fdata = (float *)data;

	/* Audio ports */
	if (port >= TAP_INS && port < TAP_OUTS) {
		port -= TAP_INS;
		ptap->ports.in[port] = fdata;
		return;
	}
	
	if (port >= TAP_OUTS && port < TAP_MATRIX) {
		port -= TAP_OUTS;
		ptap->ports.out[port] = fdata;
		return;
	}

	if (port >= TAP_MATRIX && port < TAP_GAINS) {
		port -= TAP_MATRIX;
		ptap->ports.matrix[port / NUM_GAINS][port % NUM_GAINS] = fdata;
		return;
	}

	if (port >= TAP_GAINS && port < TAP_DELAYS) {
		port -= TAP_GAINS;
		ptap->ports.gain[port] = fdata;
		return;
	}

	if (port >= TAP_DELAYS && port < TAP_END) {
		port -= TAP_DELAYS;
		ptap->ports.delay[port] = fdata;
		return;
	}

	fprintf(stderr, "Unknown port index %u\n", port);
}

static void ptap_run(LV2_Handle lv2instance, uint32_t sample_count)
{
	PTap *ptap = (PTap *)lv2instance;

	const float *readp[NUM_GAINS];
	float gain[NUM_GAINS];
	bool check_overflow = false;

	/* Position read pointers behind write pointers */
	for (int i = 0; i < NUM_TAPS; i++) {
		int delay = *ptap->ports.delay[i] * ptap->sample_rate;
		/* Zero delay results in processing order dependencies. Tapiir doesn't permit it either... */
		if (delay < 1) delay = 1;
		readp[i] = ptap->wp[i] - delay;
		if (readp[i] < ptap->buffers[i]) {
			readp[i] += ptap->buffer_max;
		}
		if (ptap->wp[i] + sample_count >= ptap->buffers_end[i]) check_overflow = true;
		if (readp[i] + sample_count >= ptap->buffers_end[i]) check_overflow = true;
		gain[i] = *ptap->ports.gain[i];
	}

	float *out[NUM_CHANNELS];
	for (int i = 0; i < NUM_CHANNELS; i++) {
		out[i]              = ptap->ports.out[i];
		readp[NUM_TAPS + i] = ptap->ports.in[i];
		gain[NUM_TAPS + i]  = *ptap->ports.gain[NUM_TAPS + i];
	}

	while (sample_count--) {
		float rp[NUM_GAINS];
		float wp[NUM_GAINS];

		/* Read input to local buffers */
		for (int i = 0; i < NUM_GAINS; i++) rp[i] = *readp[i]++;

		/* Process delays */
		for (int i = 0; i < NUM_GAINS; i++) {
			float sample = 0;
			for (int j = 0; j < NUM_GAINS; j++) sample += rp[j] * *ptap->ports.matrix[i][j];
			wp[i] = sample * gain[i];
		}

		/* Write outputs */
		for (int i = 0; i < NUM_TAPS; i++) *ptap->wp[i]++ = wp[i];
		for (int i = 0; i < NUM_CHANNELS; i++) *out[i]++ = wp[NUM_TAPS + i];

		/* Check read/write pointers */
		if (check_overflow) {
			for (int i = 0; i < NUM_TAPS; i++) {
				if (ptap->wp[i] >= ptap->buffers_end[i]) ptap->wp[i] = ptap->buffers[i];
				if (readp[i] >= ptap->buffers_end[i]) readp[i] = ptap->buffers[i];
			}
		}
	}
}

static void ptap_cleanup(LV2_Handle lv2instance)
{
	PTap *ptap = (PTap *)lv2instance;
	delete ptap;
}

static const LV2_Descriptor s_lv2descriptor =
{
	PTAP_URI,
	&ptap_instantiate,
	&ptap_connect_port,
	NULL,
	&ptap_run,
	NULL,
	&ptap_cleanup,
	NULL,
};

const LV2_Descriptor *lv2_descriptor(uint32_t index)
{
	if (index == 0) {
		return &s_lv2descriptor;
	}

	return NULL;
}