yet another example client

tokisbeats.cpp

@@ -0,0 +1,168 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/* 
+ * File:   main.cpp
+ * Author: thorsten
+ *
+ * Created on 12. August 2018, 00:23
+ */
+
+#include <cstdlib>
+#include <ctime>
+#include <cmath>
+#include <iostream>
+
+extern "C" {
+#include <jack/jack.h>
+#include <unistd.h>
+}
+
+using namespace std;
+
+float accel = 8.0;
+
+struct Instrument {
+    float freqA;
+    float freqB;
+    float shiftA;
+    float shiftB;
+    float power;
+    bool signum;
+    jack_default_audio_sample_t buffer[44100];
+
+    float compute(float x) {
+        float y = sin(x * freqA + shiftA);
+        if (signum) y = -signbit(y) * 2.0 + 1.0;
+        y *= (cos(x * freqB + shiftB) + 1.0) / 2.0;
+        y /= 1 + pow(x, power);
+        return y;
+    }
+
+    void randomize() {
+        freqA = (float) rand() / RAND_MAX * 0.19 + 0.01;
+        freqB = (float) rand() / RAND_MAX * 0.01 + 0.005;
+        shiftA = (float) rand() / RAND_MAX * 0.2;
+        shiftB = (float) rand() / RAND_MAX * 0.2;
+        power = (float) rand() / RAND_MAX * 0.2 + 0.2;
+        signum = rand() & 1;
+
+        for (int i = 0; i < sizeof (buffer) / sizeof (buffer[0]); ++i) buffer[i] = 0;
+
+        for (int i = 0; i < (float) sizeof (buffer) / (float) sizeof (buffer[0]) / accel; ++i) {
+            buffer[i] = compute((float) i / accel);
+        }
+
+        float sum = 0;
+        for (int i = 0; i < sizeof (buffer) / sizeof (buffer[0]); ++i) sum += buffer[i];
+        for (int i = 0; i < sizeof (buffer) / sizeof (buffer[0]); ++i) buffer[i] /= sum;
+        for (int i = 0; i < sizeof (buffer) / sizeof (buffer[0]); ++i) buffer[i] *= 200;
+    }
+};
+
+struct Pattern {
+    Instrument aud;
+    bool pat[16];
+
+    int bounds(int i) {
+        while (i < 0) i += 16;
+        while (i >= 16) i -= 16;
+
+        return i;
+    }
+
+    void randomize() {
+        for (int i = 0; i < 16; ++i) pat[i] = false;
+
+        for (int i = 0; i < 4; ++i) {
+            if (rand() & 1) {
+                pat[4 * i] = true;
+
+                if (rand() & 1) {
+                    pat[bounds(4 * i + 2)] = true;
+                }
+                if (rand() & 1) {
+                    pat[bounds(4 * i - 1)] = true;
+                }
+            }
+        }
+    }
+};
+
+int index = 0;
+int counter = 0;
+int x;
+jack_client_t *jc;
+jack_port_t *jp;
+Pattern patterns[10];
+
+void randomize() {
+    for (int i = 0; i < sizeof (patterns) / sizeof (patterns[0]); ++i) {
+        patterns[i].aud.randomize();
+        patterns[i].randomize();
+    }
+}
+
+int myCallback(jack_nframes_t nframes, void *arg) {
+    if (jack_port_connected(jp)) {
+        jack_default_audio_sample_t *b = (jack_default_audio_sample_t *) jack_port_get_buffer(jp, nframes);
+
+        for (int j = 0; j < nframes; ++j) {
+            b[j] = 0;
+            for (int i = 0; i < sizeof (patterns) / sizeof (patterns[0]); ++i) {
+                if (patterns[i].pat[index]) {
+                    b[j] += patterns[i].aud.buffer[x + j];
+                }
+            }
+        }
+
+        x += nframes;
+
+        if (x > (44100 / accel)) {
+            x = 0;
+            index += 1;
+
+            if (index >= 16) {
+                index = 0;
+                counter += 1;
+
+                if (counter >= 4) {
+                    counter = 0;
+                    randomize();
+                }
+            }
+        }
+    }
+
+    return 0;
+}
+
+/*
+ * 
+ */
+int main(int argc, char** argv) {
+    time_t t;
+    time(&t);
+    srand(t);
+
+    randomize();
+
+    jack_status_t stat;
+    jc = jack_client_open("TokisBeat", JackNullOption, &stat);
+    jack_set_process_callback(jc, myCallback, 0);
+
+    cout << stat << endl;
+
+    jp = jack_port_register(jc, "Mono Port", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
+    jack_activate(jc);
+
+    while (true) {
+        usleep(1000);
+    }
+
+    return 0;
+}
+