diff options
Diffstat (limited to 'plugins/eg02-midigate.lv2/midigate.c')
| -rw-r--r-- | plugins/eg02-midigate.lv2/midigate.c | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/plugins/eg02-midigate.lv2/midigate.c b/plugins/eg02-midigate.lv2/midigate.c deleted file mode 100644 index 8d2bd74..0000000 --- a/plugins/eg02-midigate.lv2/midigate.c +++ /dev/null @@ -1,227 +0,0 @@ -/* - Copyright 2013 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 <stdio.h> - -#include <math.h> -#include <stdlib.h> - -#include "lv2/lv2plug.in/ns/ext/atom/atom.h" -#include "lv2/lv2plug.in/ns/ext/atom/util.h" -#include "lv2/lv2plug.in/ns/ext/midi/midi.h" -#include "lv2/lv2plug.in/ns/ext/urid/urid.h" -#include "lv2/lv2plug.in/ns/lv2core/lv2.h" - -#define MIDIGATE_URI "http://lv2plug.in/plugins/eg-midigate" - -typedef enum { - MIDIGATE_CONTROL = 0, - MIDIGATE_IN = 1, - MIDIGATE_OUT = 2 -} PortIndex; - -typedef struct { - // Port buffers - const LV2_Atom_Sequence* control; - const float* in; - float* out; - - // Features - LV2_URID_Map* map; - - struct { - LV2_URID midi_MidiEvent; - } uris; - - unsigned n_active_notes; - unsigned program; // 0 = normal, 1 = inverted -} Midigate; - -static LV2_Handle -instantiate(const LV2_Descriptor* descriptor, - double rate, - const char* bundle_path, - const LV2_Feature* const* features) -{ - /** Scan features array for the URID feature we need. */ - LV2_URID_Map* map = NULL; - for (int i = 0; features[i]; ++i) { - if (!strcmp(features[i]->URI, LV2_URID__map)) { - map = (LV2_URID_Map*)features[i]->data; - break; - } - } - if (!map) { - /** - No URID feature given. This is a host bug since we require this - feature, but should be handled gracefully anyway. - */ - return NULL; - } - - Midigate* self = (Midigate*)calloc(1, sizeof(Midigate)); - self->map = map; - self->uris.midi_MidiEvent = map->map(map->handle, LV2_MIDI__MidiEvent); - - return (LV2_Handle)self; -} - -static void -connect_port(LV2_Handle instance, - uint32_t port, - void* data) -{ - Midigate* self = (Midigate*)instance; - - switch ((PortIndex)port) { - case MIDIGATE_CONTROL: - self->control = (const LV2_Atom_Sequence*)data; - break; - case MIDIGATE_IN: - self->in = (const float*)data; - break; - case MIDIGATE_OUT: - self->out = (float*)data; - break; - } -} - -static void -activate(LV2_Handle instance) -{ - Midigate* self = (Midigate*)instance; - self->n_active_notes = 0; - self->program = 0; -} - -/** - A function to write a chunk of output, to be called from run(). If the gate - is high, then the input will be passed through for this chunk, otherwise - silence is written. -*/ -static void -write_output(Midigate* self, uint32_t offset, uint32_t len) -{ - const bool active = (self->program == 0) - ? (self->n_active_notes > 0) - : (self->n_active_notes == 0); - if (active) { - memcpy(self->out + offset, self->in + offset, len * sizeof(float)); - } else { - memset(self->out + offset, 0, len * sizeof(float)); - } -} - -/** - This plugin works through the cycle in chunks starting at offset zero. The - +offset+ represents the current time within this this cycle, so - the output from 0 to +offset+ has already been written. - - MIDI events are read in a loop. In each iteration, the number of active - notes (on note on and note off) or the program (on program change) is - updated, then the output is written up until the current event time. Then - +offset+ is updated and the next event is processed. After the loop the - final chunk from the last event to the end of the cycle is emitted. - - There is currently no standard way to describe MIDI programs in LV2, so the - host has no way of knowing that these programs exist and should be presented - to the user. A future version of LV2 will address this shortcoming. - - This pattern of iterating over input events and writing output along the way - is a common idiom for writing sample accurate output based on event input. - - Note that this simple example simply writes input or zero for each sample - based on the gate. A serious implementation would need to envelope the - transition to avoid aliasing. -*/ -static void -run(LV2_Handle instance, uint32_t sample_count) -{ - Midigate* self = (Midigate*)instance; - uint32_t offset = 0; - - LV2_ATOM_SEQUENCE_FOREACH(self->control, ev) { - if (ev->body.type == self->uris.midi_MidiEvent) { - const uint8_t* const msg = (const uint8_t*)(ev + 1); - switch (lv2_midi_message_type(msg)) { - case LV2_MIDI_MSG_NOTE_ON: - ++self->n_active_notes; - break; - case LV2_MIDI_MSG_NOTE_OFF: - --self->n_active_notes; - break; - case LV2_MIDI_MSG_PGM_CHANGE: - if (msg[1] == 0 || msg[1] == 1) { - self->program = msg[1]; - } - break; - default: break; - } - } - - write_output(self, offset, ev->time.frames - offset); - offset = (uint32_t)ev->time.frames; - } - - write_output(self, offset, sample_count - offset); -} - -/** - We have no resources to free on deactivation. - Note that the next call to activate will re-initialise the state, namely - self->n_active_notes, so there is no need to do so here. -*/ -static void -deactivate(LV2_Handle instance) -{} - -static void -cleanup(LV2_Handle instance) -{ - free(instance); -} - -/** - This plugin also has no extension data to return. -*/ -static const void* -extension_data(const char* uri) -{ - return NULL; -} - -static const LV2_Descriptor descriptor = { - MIDIGATE_URI, - instantiate, - connect_port, - activate, - run, - deactivate, - cleanup, - extension_data -}; - -LV2_SYMBOL_EXPORT -const LV2_Descriptor* -lv2_descriptor(uint32_t index) -{ - switch (index) { - case 0: - return &descriptor; - default: - return NULL; - } -} |