Add simple oscilloscope example

examples/CMakeLists.txt

@@ -22,6 +22,9 @@ link_directories (${CMAKE_BINARY_DIR}/libol)
 add_executable(circlescope circlescope.c)
 target_link_libraries(circlescope ${JACK_LIBRARIES} m)
 
+add_executable(scope scope.c)
+target_link_libraries(scope ${JACK_LIBRARIES} m)
+
 add_executable(simple simple.c)
 target_link_libraries(simple openlase)
 

examples/scope.c

@@ -0,0 +1,134 @@
+/*
+        OpenLase - a realtime laser graphics toolkit
+
+Copyright (C) 2009-2011 Hector Martin "marcan" <hector@marcansoft.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 or version 3.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#define _BSD_SOURCE
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <jack/jack.h>
+
+#include <stdint.h>
+#include <math.h>
+
+typedef jack_default_audio_sample_t sample_t;
+typedef jack_nframes_t nframes_t;
+
+jack_port_t *in_l;
+jack_port_t *in_r;
+jack_port_t *out_x;
+jack_port_t *out_y;
+jack_port_t *out_w;
+
+nframes_t rate;
+
+sample_t max_size = 1.0f;
+sample_t min_size = 0.2f;
+sample_t boost = 8;
+
+//float w = 110 * (2*M_PI);
+float w = 523.251131f / 4.0f;
+float pos = 0.0f;
+
+#define MAX(a,b) (((a)<(b))?(b):(a))
+#define MIN(a,b) (((a)>(b))?(b):(a))
+
+int process (nframes_t nframes, void *arg)
+{
+	sample_t *i_l = (sample_t *) jack_port_get_buffer (in_l, nframes);
+	sample_t *i_r = (sample_t *) jack_port_get_buffer (in_r, nframes);
+	sample_t *o_x = (sample_t *) jack_port_get_buffer (out_x, nframes);
+	sample_t *o_y = (sample_t *) jack_port_get_buffer (out_y, nframes);
+	sample_t *o_w = (sample_t *) jack_port_get_buffer (out_w, nframes);
+
+	nframes_t frm;
+	for (frm = 0; frm < nframes; frm++) {
+		sample_t val = (*i_l++ + *i_r++) / 2;
+
+		val *= boost;
+		val = MAX(MIN(val,1.0f),-1.0f);
+
+		if (pos < 0.05 || pos > 0.95)
+			*o_w++ = 0.0f;
+		else
+			*o_w++ = 1.0f;
+		*o_x++ = pos * 2 - 1;
+		*o_y++ = val;
+
+		pos += w / rate;
+		while(pos >= 1) {
+			pos -= 1;
+		}
+	}
+
+	return 0;
+}
+
+int bufsize (nframes_t nframes, void *arg)
+{
+	printf ("the maximum buffer size is now %u\n", nframes);
+	return 0;
+}
+
+int srate (nframes_t nframes, void *arg)
+{
+	rate = nframes;
+	printf ("Sample rate: %u/sec\n", nframes);
+	return 0;
+}
+
+void jack_shutdown (void *arg)
+{
+	exit (1);
+}
+
+int main (int argc, char *argv[])
+{
+	jack_client_t *client;
+
+	if ((client = jack_client_new ("circlescope")) == 0) {
+		fprintf (stderr, "jack server not running?\n");
+		return 1;
+	}
+
+	jack_set_process_callback (client, process, 0);
+	jack_set_buffer_size_callback (client, bufsize, 0);
+	jack_set_sample_rate_callback (client, srate, 0);
+	jack_on_shutdown (client, jack_shutdown, 0);
+
+	in_l = jack_port_register (client, "in_l", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
+	in_r = jack_port_register (client, "in_r", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
+	out_x = jack_port_register (client, "out_x", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
+	out_y = jack_port_register (client, "out_y", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
+	out_w = jack_port_register (client, "out_w", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
+
+	if (jack_activate (client)) {
+		fprintf (stderr, "cannot activate client");
+		return 1;
+	}
+
+	while (1)
+		sleep(1);
+	jack_client_close (client);
+	exit (0);
+}
+