source/native-plugins/midi-channel-filter.c

   1 /*
   2  * Carla Native Plugins
   3  * Copyright (C) 2012-2019 Filipe Coelho <falktx@falktx.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * For a full copy of the GNU General Public License see the doc/GPL.txt file.
  16  */
  17
  18 #include "CarlaNative.h"
  19 #include "CarlaMIDI.h"
  20
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24
  25 // -----------------------------------------------------------------------
  26
  27 typedef struct {
  28     const NativeHostDescriptor* host;
  29     bool channels[MAX_MIDI_CHANNELS];
  30 } MidiGainHandle;
  31
  32 // -----------------------------------------------------------------------
  33
  34 static NativePluginHandle midichanfilter_instantiate(const NativeHostDescriptor* host)
  35 {
  36     MidiGainHandle* const handle = (MidiGainHandle*)malloc(sizeof(MidiGainHandle));
  37
  38     if (handle == NULL)
  39         return NULL;
  40
  41     handle->host = host;
  42
  43     for (int i=MAX_MIDI_CHANNELS; --i>=0;)
  44         handle->channels[i] = 1.0f;
  45
  46     return handle;
  47 }
  48
  49 #define handlePtr ((MidiGainHandle*)handle)
  50
  51 static void midichanfilter_cleanup(NativePluginHandle handle)
  52 {
  53     free(handlePtr);
  54 }
  55
  56 static uint32_t midichanfilter_get_parameter_count(NativePluginHandle handle)
  57 {
  58     return MAX_MIDI_CHANNELS;
  59
  60     // unused
  61     (void)handle;
  62 }
  63
  64 static const NativeParameter* midichanfilter_get_parameter_info(NativePluginHandle handle, uint32_t index)
  65 {
  66     if (index > MAX_MIDI_CHANNELS)
  67         return NULL;
  68
  69     static NativeParameter param;
  70     static const NativeParameterScalePoint scalePoints[2] = { { "Off", 0.0f }, { "On", 1.0f } };
  71     static char paramName[24];
  72
  73     param.hints = NATIVE_PARAMETER_IS_ENABLED|NATIVE_PARAMETER_IS_AUTOMATABLE|NATIVE_PARAMETER_IS_BOOLEAN|NATIVE_PARAMETER_USES_SCALEPOINTS;
  74     param.name  = paramName;
  75     param.unit  = NULL;
  76     param.ranges.def       = 1.0f;
  77     param.ranges.min       = 0.0f;
  78     param.ranges.max       = 1.0f;
  79     param.ranges.step      = 1.0f;
  80     param.ranges.stepSmall = 1.0f;
  81     param.ranges.stepLarge = 1.0f;
  82     param.scalePointCount  = 2;
  83     param.scalePoints      = scalePoints;
  84
  85     snprintf(paramName, 24, "%u", index+1);
  86
  87     return &param;
  88
  89     // unused
  90     (void)handle;
  91 }
  92
  93 static float midichanfilter_get_parameter_value(NativePluginHandle handle, uint32_t index)
  94 {
  95     if (index > MAX_MIDI_CHANNELS)
  96         return 0.0f;
  97
  98     return handlePtr->channels[index] ? 1.0f : 0.0f;
  99 }
 100
 101 static void midichanfilter_set_parameter_value(NativePluginHandle handle, uint32_t index, float value)
 102 {
 103     if (index > MAX_MIDI_CHANNELS)
 104         return;
 105
 106     handlePtr->channels[index] = (value >= 0.5f);
 107 }
 108
 109 // FIXME for v3.0, use const for the input buffer
 110 static void midichanfilter_process(NativePluginHandle handle,
 111                                    float** inBuffer, float** outBuffer, uint32_t frames,
 112                                    const NativeMidiEvent* midiEvents, uint32_t midiEventCount)
 113 {
 114     const NativeHostDescriptor* const host     = handlePtr->host;
 115     const bool*                 const channels = handlePtr->channels;
 116
 117     for (uint32_t i=0; i < midiEventCount; ++i)
 118     {
 119         const NativeMidiEvent* const midiEvent = &midiEvents[i];
 120
 121         const uint8_t status = (uint8_t)MIDI_GET_STATUS_FROM_DATA(midiEvent->data);
 122
 123         if (MIDI_IS_CHANNEL_MESSAGE(status))
 124         {
 125             const uint8_t channel = (uint8_t)MIDI_GET_CHANNEL_FROM_DATA(midiEvent->data);
 126
 127             if (channel >= MAX_MIDI_CHANNELS)
 128                 continue;
 129
 130             if (channels[channel])
 131                 host->write_midi_event(host->handle, midiEvent);
 132         }
 133         else
 134         {
 135             // pass through all non-message events
 136             host->write_midi_event(host->handle, midiEvent);
 137         }
 138     }
 139
 140     return;
 141
 142     // unused
 143     (void)inBuffer;
 144     (void)outBuffer;
 145     (void)frames;
 146 }
 147
 148 // -----------------------------------------------------------------------
 149
 150 static const NativePluginDescriptor midichanfilterDesc = {
 151     .category  = NATIVE_PLUGIN_CATEGORY_UTILITY,
 152     .hints     = NATIVE_PLUGIN_IS_RTSAFE,
 153     .supports  = NATIVE_PLUGIN_SUPPORTS_EVERYTHING,
 154     .audioIns  = 0,
 155     .audioOuts = 0,
 156     .cvIns     = 0,
 157     .cvOuts    = 0,
 158     .midiIns   = 1,
 159     .midiOuts  = 1,
 160     .paramIns  = 0,
 161     .paramOuts = 0,
 162     .name      = "MIDI Channel Filter",
 163     .label     = "midichanfilter",
 164     .maker     = "falkTX",
 165     .copyright = "GNU GPL v2+",
 166
 167     .instantiate = midichanfilter_instantiate,
 168     .cleanup     = midichanfilter_cleanup,
 169
 170     .get_parameter_count = midichanfilter_get_parameter_count,
 171     .get_parameter_info  = midichanfilter_get_parameter_info,
 172     .get_parameter_value = midichanfilter_get_parameter_value,
 173
 174     .get_midi_program_count = NULL,
 175     .get_midi_program_info  = NULL,
 176
 177     .set_parameter_value = midichanfilter_set_parameter_value,
 178     .set_midi_program    = NULL,
 179     .set_custom_data     = NULL,
 180
 181     .ui_show = NULL,
 182     .ui_idle = NULL,
 183
 184     .ui_set_parameter_value = NULL,
 185     .ui_set_midi_program    = NULL,
 186     .ui_set_custom_data     = NULL,
 187
 188     .activate   = NULL,
 189     .deactivate = NULL,
 190     .process    = midichanfilter_process,
 191
 192     .get_state = NULL,
 193     .set_state = NULL,
 194
 195     .dispatcher = NULL
 196 };
 197
 198 // -----------------------------------------------------------------------
 199
 200 void carla_register_native_plugin_midichanfilter(void);
 201
 202 void carla_register_native_plugin_midichanfilter(void)
 203 {
 204     carla_register_native_plugin(&midichanfilterDesc);
 205 }
 206
 207 // -----------------------------------------------------------------------