diff options
Diffstat (limited to 'midi_matrix_channel_filter.c')
| -rw-r--r-- | midi_matrix_channel_filter.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/midi_matrix_channel_filter.c b/midi_matrix_channel_filter.c new file mode 100644 index 0000000..b5141fc --- /dev/null +++ b/midi_matrix_channel_filter.c @@ -0,0 +1,195 @@ +/* + * Copyright (c) 2015-2016 Hanspeter Portner (dev@open-music-kontrollers.ch) + * + * This is free software: you can redistribute it and/or modify + * it under the terms of the Artistic License 2.0 as published by + * The Perl Foundation. + * + * This source 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 + * Artistic License 2.0 for more details. + * + * You should have received a copy of the Artistic License 2.0 + * along the source as a COPYING file. If not, obtain it from + * http://www.perlfoundation.org/artistic_license_2_0. + */ + +#include <midi_matrix.h> + +typedef struct _Handle Handle; + +struct _Handle { + LV2_URID_Map *map; + struct { + LV2_URID midi_MidiEvent; + } uris; + + const LV2_Atom_Sequence *midi_in; + LV2_Atom_Sequence *midi_out; + float *control [0x10]; + uint16_t mask [0x10]; + + LV2_Atom_Forge forge; + LV2_Atom_Forge_Frame frame; +}; + +static LV2_Handle +instantiate(const LV2_Descriptor* descriptor, double rate, const char *bundle_path, const LV2_Feature *const *features) +{ + int i; + Handle *handle = (Handle *)calloc(1, sizeof(Handle)); + if(!handle) + return NULL; + + for(i=0; features[i]; i++) + if(!strcmp(features[i]->URI, LV2_URID__map)) + handle->map = (LV2_URID_Map *)features[i]->data; + + if(!handle->map) + { + fprintf(stderr, "%s: Host does not support urid:map\n", descriptor->URI); + free(handle); + return NULL; + } + + handle->uris.midi_MidiEvent = handle->map->map(handle->map->handle, LV2_MIDI__MidiEvent); + lv2_atom_forge_init(&handle->forge, handle->map); + + return handle; +} + +static void +connect_port(LV2_Handle instance, uint32_t port, void *data) +{ + Handle *handle = (Handle *)instance; + switch(port) + { + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0a: + case 0x0b: + case 0x0c: + case 0x0d: + case 0x0e: + case 0x0f: + handle->control[port] = (float *)data; + break; + case 0x10: + handle->midi_in = (const LV2_Atom_Sequence *)data; + break; + case 0x11: + handle->midi_out = (LV2_Atom_Sequence *)data; + break; + default: + break; + } +} + +static void +activate(LV2_Handle instance) +{ + Handle *handle = (Handle *)instance; + //nothing +} + +static void +run(LV2_Handle instance, uint32_t sample_count) +{ + Handle *handle = (Handle *)instance; + + if(!handle->midi_in || !handle->midi_out) + return; + + // fill channel mask array + int i; + for(i=0x0; i<0x10; i++) + handle->mask[i] = (uint16_t)*handle->control[i]; + + // prepare midi atom forge + const uint32_t capacity = handle->midi_out->atom.size; + LV2_Atom_Forge *forge = &handle->forge; + lv2_atom_forge_set_buffer(forge, (uint8_t *)handle->midi_out, capacity); + lv2_atom_forge_sequence_head(forge, &handle->frame, 0); + + // process incoming events + LV2_ATOM_SEQUENCE_FOREACH(handle->midi_in, ev) + { + if(ev->body.type == handle->uris.midi_MidiEvent) + { + int64_t frames = ev->time.frames; + const uint32_t len = ev->body.size; + const uint8_t *buf = LV2_ATOM_BODY_CONST(&ev->body); + + const uint8_t cmd = buf[0] & 0xf0; + if(cmd == 0xf0) + continue; // ignore system messages + + const uint8_t src = buf[0] & 0x0f; // source channel + if(handle->mask[src]) // are there any active output channels at all for this input channel? + { + uint8_t dst; + uint16_t mask; + for(dst=0x0, mask=0x1; dst<0x10; dst++, mask=mask<<1) + { + if(handle->mask[src] & mask) // is this output channel active? + { + LV2_Atom midiatom; + midiatom.type = handle->uris.midi_MidiEvent; + midiatom.size = len; + const uint8_t m = (buf[0] & 0xf0) | dst; // rewrite channel number + + lv2_atom_forge_frame_time(forge, frames); + lv2_atom_forge_raw(forge, &midiatom, sizeof(LV2_Atom)); + lv2_atom_forge_raw(forge, &m, 1); + lv2_atom_forge_raw(forge, &buf[1], len-1); + lv2_atom_forge_pad(forge, sizeof(LV2_Atom) + len); + } + } + } + } + } + + lv2_atom_forge_pop(forge, &handle->frame); +} + +static void +deactivate(LV2_Handle instance) +{ + Handle *handle = (Handle *)instance; + //nothing +} + +static void +cleanup(LV2_Handle instance) +{ + Handle *handle = (Handle *)instance; + + free(handle); +} + +static const void* +extension_data(const char* uri) +{ + //nothing + return NULL; +} + +const LV2_Descriptor channel_filter = { + .URI = MIDI_MATRIX_CHANNEL_FILTER_URI, + .instantiate = instantiate, + .connect_port = connect_port, + .activate = activate, + .run = run, + .deactivate = deactivate, + .cleanup = cleanup, + .extension_data = extension_data +}; |