Add MIDI channel filter plugin

source/native-plugins/Makefile

@@ -48,6 +48,7 @@ OBJS = \
 OBJS += \
 	$(OBJDIR)/bypass.c.o \
 	$(OBJDIR)/lfo.c.o \
+	$(OBJDIR)/midi-channel-filter.c.o \
 	$(OBJDIR)/midi-gain.c.o \
 	$(OBJDIR)/midi-split.c.o \
 	$(OBJDIR)/midi-through.c.o \

source/native-plugins/_all.c

@@ -23,6 +23,7 @@
 // Simple plugins
 extern void carla_register_native_plugin_bypass(void);
 extern void carla_register_native_plugin_lfo(void);
+extern void carla_register_native_plugin_midichanfilter(void);
 extern void carla_register_native_plugin_midigain(void);
 extern void carla_register_native_plugin_midisplit(void);
 extern void carla_register_native_plugin_midithrough(void);
@@ -71,6 +72,7 @@ void carla_register_all_native_plugins(void)
     // Simple plugins
     carla_register_native_plugin_bypass();
     carla_register_native_plugin_lfo();
+    carla_register_native_plugin_midichanfilter();
     carla_register_native_plugin_midigain();
     carla_register_native_plugin_midisplit();
     carla_register_native_plugin_midithrough();

source/native-plugins/_data.cpp

@@ -62,6 +62,22 @@ static const NativePluginDescriptor sNativePluginDescriptors[] = {
     /* copyright */ "GNU GPL v2+",
     DESCFUNCS
 },
+{
+    /* category  */ NATIVE_PLUGIN_CATEGORY_UTILITY,
+    /* hints     */ NATIVE_PLUGIN_IS_RTSAFE,
+    /* supports  */ NATIVE_PLUGIN_SUPPORTS_EVERYTHING,
+    /* audioIns  */ 0,
+    /* audioOuts */ 0,
+    /* midiIns   */ 1,
+    /* midiOuts  */ 1,
+    /* paramIns  */ 0,
+    /* paramOuts */ 0,
+    /* name      */ "MIDI Channel Filter",
+    /* label     */ "midichanfilter",
+    /* maker     */ "falkTX",
+    /* copyright */ "GNU GPL v2+",
+    DESCFUNCS
+},
 {
     /* category  */ NATIVE_PLUGIN_CATEGORY_UTILITY,
     /* hints     */ NATIVE_PLUGIN_IS_RTSAFE,

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

@@ -0,0 +1,200 @@
+/*
+ * Carla Native Plugins
+ * Copyright (C) 2012-2015 Filipe Coelho <falktx@falktx.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or any later version.
+ *
+ * This program 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
+ * GNU General Public License for more details.
+ *
+ * For a full copy of the GNU General Public License see the doc/GPL.txt file.
+ */
+
+#include "CarlaNative.h"
+#include "CarlaMIDI.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+// -----------------------------------------------------------------------
+
+typedef struct {
+    const NativeHostDescriptor* host;
+    bool channels[MAX_MIDI_CHANNELS];
+} MidiGainHandle;
+
+// -----------------------------------------------------------------------
+
+static NativePluginHandle midichanfilter_instantiate(const NativeHostDescriptor* host)
+{
+    MidiGainHandle* const handle = (MidiGainHandle*)malloc(sizeof(MidiGainHandle));
+
+    if (handle == NULL)
+        return NULL;
+
+    handle->host = host;
+    memset(handle->channels, 0, sizeof(bool)*MAX_MIDI_CHANNELS);
+
+    return handle;
+}
+
+#define handlePtr ((MidiGainHandle*)handle)
+
+static void midichanfilter_cleanup(NativePluginHandle handle)
+{
+    free(handlePtr);
+}
+
+static uint32_t midichanfilter_get_parameter_count(NativePluginHandle handle)
+{
+    return MAX_MIDI_CHANNELS;
+
+    // unused
+    (void)handle;
+}
+
+static const NativeParameter* midichanfilter_get_parameter_info(NativePluginHandle handle, uint32_t index)
+{
+    if (index > MAX_MIDI_CHANNELS)
+        return NULL;
+
+    static NativeParameter param;
+    static char paramName[24];
+
+    param.hints = NATIVE_PARAMETER_IS_ENABLED|NATIVE_PARAMETER_IS_AUTOMABLE|NATIVE_PARAMETER_IS_BOOLEAN;
+    param.name  = paramName;
+    param.unit  = NULL;
+    param.ranges.def       = 1.0f;
+    param.ranges.min       = 0.0f;
+    param.ranges.max       = 0.0f;
+    param.ranges.step      = 1.0f;
+    param.ranges.stepSmall = 1.0f;
+    param.ranges.stepLarge = 1.0f;
+    param.scalePointCount  = 0;
+    param.scalePoints      = NULL;
+
+    snprintf(paramName, 24, "%u", index+1);
+
+    return &param;
+
+    // unused
+    (void)handle;
+}
+
+static float midichanfilter_get_parameter_value(NativePluginHandle handle, uint32_t index)
+{
+    if (index > MAX_MIDI_CHANNELS)
+        return 0.0f;
+
+    return handlePtr->channels[index] ? 1.0f : 0.0f;
+}
+
+static void midichanfilter_set_parameter_value(NativePluginHandle handle, uint32_t index, float value)
+{
+    if (index > MAX_MIDI_CHANNELS)
+        return;
+
+    handlePtr->channels[index] = (value >= 0.5f);
+}
+
+static void midichanfilter_process(NativePluginHandle handle, float** inBuffer, float** outBuffer, uint32_t frames, const NativeMidiEvent* midiEvents, uint32_t midiEventCount)
+{
+    const NativeHostDescriptor* const host     = handlePtr->host;
+    const bool*                 const channels = handlePtr->channels;
+
+    for (uint32_t i=0; i < midiEventCount; ++i)
+    {
+        const NativeMidiEvent* const midiEvent = &midiEvents[i];
+
+        const uint8_t status = (uint8_t)MIDI_GET_STATUS_FROM_DATA(midiEvent->data);
+
+        if (MIDI_IS_CHANNEL_MESSAGE(status))
+        {
+            const uint8_t channel = (uint8_t)MIDI_GET_CHANNEL_FROM_DATA(midiEvent->data);
+
+            if (channel >= MAX_MIDI_CHANNELS)
+                continue;
+
+            if (channels[channel])
+                host->write_midi_event(host->handle, midiEvent);
+        }
+        else
+        {
+            // pass through all non-message events
+            host->write_midi_event(host->handle, midiEvent);
+        }
+    }
+
+    return;
+
+    // unused
+    (void)inBuffer;
+    (void)outBuffer;
+    (void)frames;
+}
+
+// -----------------------------------------------------------------------
+
+static const NativePluginDescriptor midichanfilterDesc = {
+    .category  = NATIVE_PLUGIN_CATEGORY_UTILITY,
+    .hints     = NATIVE_PLUGIN_IS_RTSAFE,
+    .supports  = NATIVE_PLUGIN_SUPPORTS_EVERYTHING,
+    .audioIns  = 0,
+    .audioOuts = 0,
+    .midiIns   = 1,
+    .midiOuts  = 1,
+    .paramIns  = 0,
+    .paramOuts = 0,
+    .name      = "MIDI Channel Filter",
+    .label     = "midichanfilter",
+    .maker     = "falkTX",
+    .copyright = "GNU GPL v2+",
+
+    .instantiate = midichanfilter_instantiate,
+    .cleanup     = midichanfilter_cleanup,
+
+    .get_parameter_count = midichanfilter_get_parameter_count,
+    .get_parameter_info  = midichanfilter_get_parameter_info,
+    .get_parameter_value = midichanfilter_get_parameter_value,
+    .get_parameter_text  = NULL,
+
+    .get_midi_program_count = NULL,
+    .get_midi_program_info  = NULL,
+
+    .set_parameter_value = midichanfilter_set_parameter_value,
+    .set_midi_program    = NULL,
+    .set_custom_data     = NULL,
+
+    .ui_show = NULL,
+    .ui_idle = NULL,
+
+    .ui_set_parameter_value = NULL,
+    .ui_set_midi_program    = NULL,
+    .ui_set_custom_data     = NULL,
+
+    .activate   = NULL,
+    .deactivate = NULL,
+    .process    = midichanfilter_process,
+
+    .get_state = NULL,
+    .set_state = NULL,
+
+    .dispatcher = NULL
+};
+
+// -----------------------------------------------------------------------
+
+void carla_register_native_plugin_midichanfilter(void);
+
+void carla_register_native_plugin_midichanfilter(void)
+{
+    carla_register_native_plugin(&midichanfilterDesc);
+}
+
+// -----------------------------------------------------------------------