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-rw-r--r--plugins/eg-metro.lv2/README.txt9
-rw-r--r--plugins/eg-metro.lv2/manifest.ttl.in7
-rw-r--r--plugins/eg-metro.lv2/metro.c352
-rw-r--r--plugins/eg-metro.lv2/metro.ttl30
l---------plugins/eg-metro.lv2/waf1
-rw-r--r--plugins/eg-metro.lv2/wscript64
6 files changed, 463 insertions, 0 deletions
diff --git a/plugins/eg-metro.lv2/README.txt b/plugins/eg-metro.lv2/README.txt
new file mode 100644
index 0000000..5e9a84a
--- /dev/null
+++ b/plugins/eg-metro.lv2/README.txt
@@ -0,0 +1,9 @@
+== Metronome ==
+
+This plugin demonstrates tempo synchronisation by clicking on every beat. The
+host sends this information to the plugin as events, so an event with new time
+and tempo information will be received whenever there is a change.
+
+Time is assumed to continue rolling at the tempo and speed defined by the last
+received tempo event, even across cycles, until a new tempo event is received
+or the plugin is deactivated.
diff --git a/plugins/eg-metro.lv2/manifest.ttl.in b/plugins/eg-metro.lv2/manifest.ttl.in
new file mode 100644
index 0000000..bd93f66
--- /dev/null
+++ b/plugins/eg-metro.lv2/manifest.ttl.in
@@ -0,0 +1,7 @@
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+
+<http://lv2plug.in/plugins/eg-metro>
+ a lv2:Plugin ;
+ lv2:binary <metro@LIB_EXT@> ;
+ rdfs:seeAlso <metro.ttl> .
diff --git a/plugins/eg-metro.lv2/metro.c b/plugins/eg-metro.lv2/metro.c
new file mode 100644
index 0000000..5e484b7
--- /dev/null
+++ b/plugins/eg-metro.lv2/metro.c
@@ -0,0 +1,352 @@
+/*
+ LV2 Metronome Example Plugin
+ Copyright 2012 David Robillard <d@drobilla.net>
+
+ 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 <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifndef __cplusplus
+# include <stdbool.h>
+#endif
+
+#include "lv2/lv2plug.in/ns/ext/atom/atom.h"
+#include "lv2/lv2plug.in/ns/ext/atom/util.h"
+#include "lv2/lv2plug.in/ns/ext/time/time.h"
+#include "lv2/lv2plug.in/ns/ext/urid/urid.h"
+#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
+
+#ifndef M_PI
+# define M_PI 3.14159265
+#endif
+
+#define EG_METRO_URI "http://lv2plug.in/plugins/eg-metro"
+
+typedef struct {
+ LV2_URID atom_Blank;
+ LV2_URID atom_Float;
+ LV2_URID atom_Object;
+ LV2_URID atom_Path;
+ LV2_URID atom_Resource;
+ LV2_URID atom_Sequence;
+ LV2_URID time_Position;
+ LV2_URID time_barBeat;
+ LV2_URID time_beatsPerMinute;
+ LV2_URID time_speed;
+} MetroURIs;
+
+static const double attack_s = 0.005;
+static const double decay_s = 0.075;
+
+enum {
+ METRO_CONTROL = 0,
+ METRO_OUT = 1
+};
+
+/** During execution this plugin can be in one of 3 states: */
+typedef enum {
+ STATE_ATTACK, // Envelope rising
+ STATE_DECAY, // Envelope lowering
+ STATE_OFF // Silent
+} State;
+
+/**
+ This plugin must keep track of more state than previous examples to be able
+ to render audio. The basic idea is to generate a single cycle of a sine
+ wave which is conceptually played continuously. The 'tick' is generated by
+ enveloping the amplitude so there is a short attack/decay peak around a
+ tick, and silence the rest of the time.
+
+ This example uses a simple AD envelope with fixed parameters. A more
+ sophisticated implementation might use a more advanced envelope and allow
+ the user to modify these parameters, the frequency of the wave, and so on.
+ */
+typedef struct {
+ LV2_URID_Map* map; // URID map feature
+ MetroURIs uris; // Cache of mapped URIDs
+
+ struct {
+ LV2_Atom_Sequence* control;
+ float* output;
+ } ports;
+
+ // Variables to keep track of the tempo information sent by the host
+ double rate; // Sample rate
+ float bpm; // Beats per minute (tempo)
+ float speed; // Transport speed (usually 0=stop, 1=play)
+
+ uint32_t elapsed_len; // Frames since the start of the last click
+ uint32_t wave_offset; // Current play offset in the wave
+ State state; // Current play state
+
+ // One cycle of a sine wave
+ float* wave;
+ uint32_t wave_len;
+
+ // Envelope parameters
+ uint32_t attack_len;
+ uint32_t decay_len;
+} Metro;
+
+static void
+connect_port(LV2_Handle instance,
+ uint32_t port,
+ void* data)
+{
+ Metro* self = (Metro*)instance;
+
+ switch (port) {
+ case METRO_CONTROL:
+ self->ports.control = (LV2_Atom_Sequence*)data;
+ break;
+ case METRO_OUT:
+ self->ports.output = (float*)data;
+ break;
+ default:
+ break;
+ }
+}
+
+/**
+ The activate() method resets the state completely, so the wave offset is
+ zero and the envelope is off.
+*/
+static void
+activate(LV2_Handle instance)
+{
+ Metro* self = (Metro*)instance;
+
+ self->elapsed_len = 0;
+ self->wave_offset = 0;
+ self->state = STATE_OFF;
+}
+
+/**
+ This plugin does a bit more work in instantiate() than the previous
+ examples. The tempo updates from the host contain several URIs, so those
+ are mapped, and the sine wave to be played needs to be generated based on
+ the current sample rate.
+*/
+static LV2_Handle
+instantiate(const LV2_Descriptor* descriptor,
+ double rate,
+ const char* path,
+ const LV2_Feature* const* features)
+{
+ Metro* self = (Metro*)calloc(1, sizeof(Metro));
+ if (!self) {
+ return NULL;
+ }
+
+ // Scan host features for URID map
+ LV2_URID_Map* map = NULL;
+ for (int i = 0; features[i]; ++i) {
+ if (!strcmp(features[i]->URI, LV2_URID_URI "#map")) {
+ map = (LV2_URID_Map*)features[i]->data;
+ }
+ }
+ if (!map) {
+ fprintf(stderr, "Host does not support urid:map.\n");
+ free(self);
+ return NULL;
+ }
+
+ // Map URIS
+ MetroURIs* const uris = &self->uris;
+ self->map = map;
+ uris->atom_Blank = map->map(map->handle, LV2_ATOM__Blank);
+ uris->atom_Float = map->map(map->handle, LV2_ATOM__Float);
+ uris->atom_Object = map->map(map->handle, LV2_ATOM__Object);
+ uris->atom_Path = map->map(map->handle, LV2_ATOM__Path);
+ uris->atom_Resource = map->map(map->handle, LV2_ATOM__Resource);
+ uris->atom_Sequence = map->map(map->handle, LV2_ATOM__Sequence);
+ uris->time_Position = map->map(map->handle, LV2_TIME__Position);
+ uris->time_barBeat = map->map(map->handle, LV2_TIME__barBeat);
+ uris->time_beatsPerMinute = map->map(map->handle, LV2_TIME__beatsPerMinute);
+ uris->time_speed = map->map(map->handle, LV2_TIME__speed);
+
+ // Initialise instance fields
+ self->rate = rate;
+ self->bpm = 120.0f;
+ self->attack_len = (uint32_t)(attack_s * rate);
+ self->decay_len = (uint32_t)(decay_s * rate);
+ self->state = STATE_OFF;
+
+ // Generate one cycle of a sine wave at the desired frequency
+ const double freq = 440.0 * 2.0;
+ const double amp = 0.5;
+ self->wave_len = (uint32_t)(rate / freq);
+ self->wave = (float*)malloc(self->wave_len * sizeof(float));
+ for (uint32_t i = 0; i < self->wave_len; ++i) {
+ self->wave[i] = (float)(sin(i * 2 * M_PI * freq / rate) * amp);
+ }
+
+ return (LV2_Handle)self;
+}
+
+static void
+cleanup(LV2_Handle instance)
+{
+ free(instance);
+}
+
+/**
+ Play back audio for the range [begin..end) relative to this cycle. This is
+ called by run() in-between events to output audio up until the current time.
+*/
+static void
+play(Metro* self, uint32_t begin, uint32_t end)
+{
+ float* const output = self->ports.output;
+ const uint32_t frames_per_beat = 60.0f / self->bpm * self->rate;
+
+ if (self->speed == 0.0f) {
+ memset(output, 0, (end - begin) * sizeof(float));
+ return;
+ }
+
+ for (uint32_t i = begin; i < end; ++i) {
+ switch (self->state) {
+ case STATE_ATTACK:
+ // Amplitude increases from 0..1 until attack_len
+ output[i] = self->wave[self->wave_offset] *
+ self->elapsed_len / (float)self->attack_len;
+ if (self->elapsed_len >= self->attack_len) {
+ self->state = STATE_DECAY;
+ }
+ break;
+ case STATE_DECAY:
+ // Amplitude decreases from 1..0 until attack_len + decay_len
+ output[i] = 0.0f;
+ output[i] = self->wave[self->wave_offset] *
+ (1 - ((self->elapsed_len - self->attack_len) /
+ (float)self->decay_len));
+ if (self->elapsed_len >= self->attack_len + self->decay_len) {
+ self->state = STATE_OFF;
+ }
+ break;
+ case STATE_OFF:
+ output[i] = 0.0f;
+ }
+
+ // We continuously play the sine wave regardless of envelope
+ self->wave_offset = (self->wave_offset + 1) % self->wave_len;
+
+ // Update elapsed time and start attack if necessary
+ if (++self->elapsed_len == frames_per_beat) {
+ self->state = STATE_ATTACK;
+ self->elapsed_len = 0;
+ }
+ }
+}
+
+/**
+ Update the current position based on a host message. This is called by
+ run() when a time:Position is received.
+*/
+static void
+update_position(Metro* self, const LV2_Atom_Object* obj)
+{
+ const MetroURIs* uris = &self->uris;
+
+ // Received new transport position/speed
+ LV2_Atom *beat = NULL, *bpm = NULL, *speed = NULL;
+ lv2_atom_object_get(obj,
+ uris->time_barBeat, &beat,
+ uris->time_beatsPerMinute, &bpm,
+ uris->time_speed, &speed,
+ NULL);
+ if (bpm && bpm->type == uris->atom_Float) {
+ // Tempo changed, update BPM
+ self->bpm = ((LV2_Atom_Float*)bpm)->body;
+ }
+ if (speed && speed->type == uris->atom_Float) {
+ // Speed changed, e.g. 0 (stop) to 1 (play)
+ self->speed = ((LV2_Atom_Float*)speed)->body;
+ }
+ if (beat && beat->type == uris->atom_Float) {
+ // Received a beat position, synchronise
+ // This hard sync may cause clicks, a real plugin would be more graceful
+ const float frames_per_beat = 60.0f / self->bpm * self->rate;
+ const float bar_beats = ((LV2_Atom_Float*)beat)->body;
+ const float beat_beats = bar_beats - floorf(bar_beats);
+ self->elapsed_len = beat_beats * frames_per_beat;
+ if (self->elapsed_len < self->attack_len) {
+ self->state = STATE_ATTACK;
+ } else if (self->elapsed_len < self->attack_len + self->decay_len) {
+ self->state = STATE_DECAY;
+ } else {
+ self->state = STATE_OFF;
+ }
+ }
+}
+
+static void
+run(LV2_Handle instance, uint32_t sample_count)
+{
+ Metro* self = (Metro*)instance;
+ const MetroURIs* uris = &self->uris;
+
+ // Work forwards in time frame by frame, handling events as we go
+ const LV2_Atom_Sequence* in = self->ports.control;
+ uint32_t last_t = 0;
+ for (const LV2_Atom_Event* ev = lv2_atom_sequence_begin(&in->body);
+ !lv2_atom_sequence_is_end(&in->body, in->atom.size, ev);
+ ev = lv2_atom_sequence_next(ev)) {
+
+ // Play the click for the time slice from last_t until now
+ play(self, last_t, ev->time.frames);
+
+ // Check if this event is an Object
+ // (or deprecated Blank to tolerate old hosts)
+ if (ev->body.type == uris->atom_Object ||
+ ev->body.type == uris->atom_Blank) {
+ const LV2_Atom_Object* obj = (const LV2_Atom_Object*)&ev->body;
+ if (obj->body.otype == uris->time_Position) {
+ // Received position information, update
+ update_position(self, obj);
+ }
+ }
+
+ // Update time for next iteration and move to next event
+ last_t = ev->time.frames;
+ }
+
+ // Play for remainder of cycle
+ play(self, last_t, sample_count);
+}
+
+static const LV2_Descriptor descriptor = {
+ EG_METRO_URI,
+ instantiate,
+ connect_port,
+ activate,
+ run,
+ NULL, // deactivate,
+ cleanup,
+ NULL, // extension_data
+};
+
+LV2_SYMBOL_EXPORT const LV2_Descriptor*
+lv2_descriptor(uint32_t index)
+{
+ switch (index) {
+ case 0:
+ return &descriptor;
+ default:
+ return NULL;
+ }
+}
diff --git a/plugins/eg-metro.lv2/metro.ttl b/plugins/eg-metro.lv2/metro.ttl
new file mode 100644
index 0000000..8b4af3d
--- /dev/null
+++ b/plugins/eg-metro.lv2/metro.ttl
@@ -0,0 +1,30 @@
+@prefix atom: <http://lv2plug.in/ns/ext/atom#> .
+@prefix doap: <http://usefulinc.com/ns/doap#> .
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix time: <http://lv2plug.in/ns/ext/time#> .
+@prefix urid: <http://lv2plug.in/ns/ext/urid#> .
+
+<http://lv2plug.in/plugins/eg-metro>
+ a lv2:Plugin ;
+ doap:name "Example Metronome" ;
+ doap:license <http://opensource.org/licenses/isc> ;
+ lv2:project <http://lv2plug.in/ns/lv2> ;
+ lv2:requiredFeature urid:map ;
+ lv2:optionalFeature lv2:hardRTCapable ;
+ lv2:port [
+ a lv2:InputPort ,
+ atom:AtomPort ;
+ atom:bufferType atom:Sequence ;
+# Since this port supports time:Position, the host knows to deliver time and
+# tempo information
+ atom:supports time:Position ;
+ lv2:index 0 ;
+ lv2:symbol "control" ;
+ lv2:name "Control" ;
+ ] , [
+ a lv2:AudioPort ,
+ lv2:OutputPort ;
+ lv2:index 1 ;
+ lv2:symbol "out" ;
+ lv2:name "Out" ;
+ ] .
diff --git a/plugins/eg-metro.lv2/waf b/plugins/eg-metro.lv2/waf
new file mode 120000
index 0000000..59a1ac9
--- /dev/null
+++ b/plugins/eg-metro.lv2/waf
@@ -0,0 +1 @@
+../../waf \ No newline at end of file
diff --git a/plugins/eg-metro.lv2/wscript b/plugins/eg-metro.lv2/wscript
new file mode 100644
index 0000000..40642b6
--- /dev/null
+++ b/plugins/eg-metro.lv2/wscript
@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+from waflib.extras import autowaf as autowaf
+import re
+
+# Variables for 'waf dist'
+APPNAME = 'eg-metro.lv2'
+VERSION = '1.0.0'
+
+# Mandatory variables
+top = '.'
+out = 'build'
+
+def options(opt):
+ opt.load('compiler_c')
+ autowaf.set_options(opt)
+
+def configure(conf):
+ conf.load('compiler_c')
+ autowaf.configure(conf)
+ autowaf.set_c99_mode(conf)
+ autowaf.display_header('Metro Configuration')
+
+ if not autowaf.is_child():
+ autowaf.check_pkg(conf, 'lv2', atleast_version='0.2.0', uselib_store='LV2')
+
+ autowaf.display_msg(conf, 'LV2 bundle directory', conf.env.LV2DIR)
+ print('')
+
+def build(bld):
+ bundle = 'eg-metro.lv2'
+
+ # Make a pattern for shared objects without the 'lib' prefix
+ module_pat = re.sub('^lib', '', bld.env.cshlib_PATTERN)
+ module_ext = module_pat[module_pat.rfind('.'):]
+
+ # Build manifest.ttl by substitution (for portable lib extension)
+ bld(features = 'subst',
+ source = 'manifest.ttl.in',
+ target = '%s/%s' % (bundle, 'manifest.ttl'),
+ install_path = '${LV2DIR}/%s' % bundle,
+ LIB_EXT = module_ext)
+
+ # Copy other data files to build bundle (build/eg-metro.lv2)
+ bld(features = 'subst',
+ is_copy = True,
+ source = 'metro.ttl',
+ target = '%s/metro.ttl' % bundle,
+ install_path = '${LV2DIR}/%s' % bundle)
+
+ # Use LV2 headers from parent directory if building as a sub-project
+ includes = ['.']
+ if autowaf.is_child:
+ includes += ['../..']
+
+ # Build plugin library
+ obj = bld(features = 'c cshlib',
+ source = 'metro.c',
+ name = 'metro',
+ target = '%s/metro' % bundle,
+ install_path = '${LV2DIR}/%s' % bundle,
+ use = 'LV2',
+ includes = includes)
+ obj.env.cshlib_PATTERN = module_pat
+
generated by cgit v1.2.1 (git 2.18.0) at 2024-12-28 12:45:19 +0000