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Diffstat (limited to 'plugins/eg-fifths.lv2/fifths.c')
| -rw-r--r-- | plugins/eg-fifths.lv2/fifths.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/plugins/eg-fifths.lv2/fifths.c b/plugins/eg-fifths.lv2/fifths.c new file mode 100644 index 0000000..c7d12e1 --- /dev/null +++ b/plugins/eg-fifths.lv2/fifths.c @@ -0,0 +1,196 @@ +/* + LV2 Fifths Example Plugin + Copyright 2014 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 <stdlib.h> +#include <string.h> +#ifndef __cplusplus +# include <stdbool.h> +#endif + +#include <sndfile.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/patch/patch.h" +#include "lv2/lv2plug.in/ns/ext/state/state.h" +#include "lv2/lv2plug.in/ns/ext/urid/urid.h" +#include "lv2/lv2plug.in/ns/lv2core/lv2.h" + +#include "./uris.h" + +enum { + FIFTHS_IN = 0, + FIFTHS_OUT = 1 +}; + +typedef struct { + // Features + LV2_URID_Map* map; + + // Ports + const LV2_Atom_Sequence* in_port; + LV2_Atom_Sequence* out_port; + + // URIs + FifthsURIs uris; +} Fifths; + +static void +connect_port(LV2_Handle instance, + uint32_t port, + void* data) +{ + Fifths* self = (Fifths*)instance; + switch (port) { + case FIFTHS_IN: + self->in_port = (const LV2_Atom_Sequence*)data; + break; + case FIFTHS_OUT: + self->out_port = (LV2_Atom_Sequence*)data; + break; + default: + break; + } +} + +static LV2_Handle +instantiate(const LV2_Descriptor* descriptor, + double rate, + const char* path, + const LV2_Feature* const* features) +{ + // Allocate and initialise instance structure. + Fifths* self = (Fifths*)malloc(sizeof(Fifths)); + if (!self) { + return NULL; + } + memset(self, 0, sizeof(Fifths)); + + // Get host features + for (int i = 0; features[i]; ++i) { + if (!strcmp(features[i]->URI, LV2_URID__map)) { + self->map = (LV2_URID_Map*)features[i]->data; + } + } + if (!self->map) { + fprintf(stderr, "Missing feature urid:map\n"); + free(self); + return NULL; + } + + // Map URIs and initialise forge/logger + map_fifths_uris(self->map, &self->uris); + + return (LV2_Handle)self; +} + +static void +cleanup(LV2_Handle instance) +{ + free(instance); +} + +static void +run(LV2_Handle instance, + uint32_t sample_count) +{ + Fifths* self = (Fifths*)instance; + FifthsURIs* uris = &self->uris; + + // Struct for a 3 byte MIDI event, used for writing notes + typedef struct { + LV2_Atom_Event event; + uint8_t msg[3]; + } MIDINoteEvent; + + // Initially self->out_port contains a Chunk with size set to capacity + + // Get the capacity + const uint32_t out_capacity = self->out_port->atom.size; + + // Write an empty Sequence header to the output + lv2_atom_sequence_clear(self->out_port); + self->out_port->atom.type = self->in_port->atom.type; + + // Read incoming events + LV2_ATOM_SEQUENCE_FOREACH(self->in_port, ev) { + if (ev->body.type == uris->midi_Event) { + const uint8_t* const msg = (const uint8_t*)(ev + 1); + switch (lv2_midi_message_type(msg)) { + case LV2_MIDI_MSG_NOTE_ON: + case LV2_MIDI_MSG_NOTE_OFF: + // Forward note to output + lv2_atom_sequence_append_event( + self->out_port, out_capacity, ev); + + const uint8_t note = msg[1]; + if (note <= 127 - 7) { + // Make a note one 5th (7 semitones) higher than input + MIDINoteEvent fifth; + + // Could simply do fifth.event = *ev here instead... + fifth.event.time.frames = ev->time.frames; // Same time + fifth.event.body.type = ev->body.type; // Same type + fifth.event.body.size = ev->body.size; // Same size + + fifth.msg[0] = msg[0]; // Same status + fifth.msg[1] = msg[1] + 7; // Pitch up 7 semitones + fifth.msg[2] = msg[2]; // Same velocity + + // Write 5th event + lv2_atom_sequence_append_event( + self->out_port, out_capacity, &fifth.event); + } + break; + default: + // Forward all other MIDI events directly + lv2_atom_sequence_append_event( + self->out_port, out_capacity, ev); + break; + } + } + } +} + +static const void* +extension_data(const char* uri) +{ + return NULL; +} + +static const LV2_Descriptor descriptor = { + EG_FIFTHS_URI, + instantiate, + connect_port, + NULL, // activate, + run, + NULL, // deactivate, + cleanup, + extension_data +}; + +LV2_SYMBOL_EXPORT +const LV2_Descriptor* lv2_descriptor(uint32_t index) +{ + switch (index) { + case 0: + return &descriptor; + default: + return NULL; + } +} |