New native plugin for forcing all midi to a particular channel (#780)

* New native plugin for forcing all midi to a particular channel

* Update midi-channelize.c

* Update _data.cpp

* Update midi-channelize.c

source/native-plugins/Makefile

@@ -29,6 +29,7 @@ OBJS = \
 	$(OBJDIR)/lfo.c.o \
 	$(OBJDIR)/midi-channel-filter.c.o \
 	$(OBJDIR)/midi-channel-ab.c.o \
+	$(OBJDIR)/midi-channelize.c.o \
 	$(OBJDIR)/midi-gain.c.o \
 	$(OBJDIR)/midi-join.c.o \
 	$(OBJDIR)/midi-split.c.o \

source/native-plugins/_all.c

@@ -30,6 +30,7 @@ extern void carla_register_native_plugin_midijoin(void);
 extern void carla_register_native_plugin_midisplit(void);
 extern void carla_register_native_plugin_midithrough(void);
 extern void carla_register_native_plugin_miditranspose(void);
+extern void carla_register_native_plugin_midichannelize(void);
 
 // Audio file
 extern void carla_register_native_plugin_audiofile(void);
@@ -65,6 +66,7 @@ void carla_register_all_native_plugins(void)
     carla_register_native_plugin_midisplit();
     carla_register_native_plugin_midithrough();
     carla_register_native_plugin_miditranspose();
+    carla_register_native_plugin_midichannelize();
 
     // Audio file
     carla_register_native_plugin_audiofile();

source/native-plugins/_data.cpp

@@ -175,6 +175,22 @@ 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  */ 1,
+    /* paramOuts */ 0,
+    /* name      */ "MIDI Channelize",
+    /* label     */ "midichannelize",
+    /* maker     */ "falkTX",
+    /* copyright */ "GNU GPL v2+",
+    DESCFUNCS
+},
 
 // --------------------------------------------------------------------------------------------------------------------
 // Audio file

source/native-plugins/midi-channelize.c

@@ -0,0 +1,210 @@
+/*
+ * Carla Native Plugins
+ * Copyright (C) 2012-2018 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>
+
+// -----------------------------------------------------------------------
+
+typedef enum {
+    PARAM_CHANNEL = 0,
+    PARAM_COUNT
+} MidiChannelizeParams;
+
+typedef struct {
+    const NativeHostDescriptor* host;
+    int channel;
+} MidiChannelizeHandle;
+
+// -----------------------------------------------------------------------
+
+static NativePluginHandle midichannelize_instantiate(const NativeHostDescriptor* host)
+{
+    MidiChannelizeHandle* const handle = (MidiChannelizeHandle*)malloc(sizeof(MidiChannelizeHandle));
+
+    if (handle == NULL)
+        return NULL;
+
+    handle->host    = host;
+    handle->channel = 1;
+    return handle;
+}
+
+#define handlePtr ((MidiChannelizeHandle*)handle)
+
+static void midichannelize_cleanup(NativePluginHandle handle)
+{
+    free(handlePtr);
+}
+
+static uint32_t midichannelize_get_parameter_count(NativePluginHandle handle)
+{
+    return PARAM_COUNT;
+
+    // unused
+    (void)handle;
+}
+
+static const NativeParameter* midichannelize_get_parameter_info(NativePluginHandle handle, uint32_t index)
+{
+    if (index > PARAM_COUNT)
+        return NULL;
+
+    static NativeParameter param;
+
+    param.hints = NATIVE_PARAMETER_IS_ENABLED|NATIVE_PARAMETER_IS_AUTOMABLE|NATIVE_PARAMETER_IS_INTEGER;
+    param.unit  = NULL;
+    param.scalePointCount = 0;
+    param.scalePoints     = NULL;
+
+    switch (index)
+    {
+    case PARAM_CHANNEL:
+        param.name = "Channel";
+        param.ranges.def = 1.0f,
+        param.ranges.min = 1.0f,
+        param.ranges.max = 16.0f,
+        param.ranges.step = 1.0f;
+        param.ranges.stepSmall = 1.0f;
+        param.ranges.stepLarge = 1.0f;
+        break;
+    }
+
+    return &param;
+
+    // unused
+    (void)handle;
+}
+
+static float midichannelize_get_parameter_value(NativePluginHandle handle, uint32_t index)
+{
+    switch (index)
+    {
+    case PARAM_CHANNEL:
+        return (float)handlePtr->channel;
+    default:
+        return 0.0f;
+    }
+}
+
+static void midichannelize_set_parameter_value(NativePluginHandle handle, uint32_t index, float value)
+{
+    switch (index)
+    {
+    case PARAM_CHANNEL:
+        handlePtr->channel = (int)value;
+        break;
+    }
+}
+
+static void midichannelize_process(NativePluginHandle handle, float** inBuffer, float** outBuffer, uint32_t frames, const NativeMidiEvent* midiEvents, uint32_t midiEventCount)
+{
+    const NativeHostDescriptor* const host = handlePtr->host;
+    const int channel = handlePtr->channel;
+    NativeMidiEvent tmpEvent;
+
+    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))
+        {
+            tmpEvent.port = midiEvent->port;
+            tmpEvent.time = midiEvent->time;
+
+            tmpEvent.data[0] = status | (channel - 1);
+            tmpEvent.data[1] = midiEvent->data[1];
+            tmpEvent.data[2] = midiEvent->data[2];
+            tmpEvent.data[3] = midiEvent->data[3];
+            tmpEvent.size = midiEvent->size;
+
+            host->write_midi_event(host->handle, &tmpEvent);
+        }
+    }
+
+    return;
+
+    // unused
+    (void)inBuffer;
+    (void)outBuffer;
+    (void)frames;
+}
+
+#undef handlePtr
+
+// -----------------------------------------------------------------------
+
+static const NativePluginDescriptor midichannelizeDesc = {
+    .category  = NATIVE_PLUGIN_CATEGORY_UTILITY,
+    .hints     = NATIVE_PLUGIN_IS_RTSAFE,
+    .supports  = NATIVE_PLUGIN_SUPPORTS_EVERYTHING,
+    .audioIns  = 0,
+    .audioOuts = 0,
+    .midiIns   = 1,
+    .midiOuts  = 1,
+    .paramIns  = 1,
+    .paramOuts = 0,
+    .name      = "MIDI Channelize",
+    .label     = "midichannelize",
+    .maker     = "falkTX",
+    .copyright = "GNU GPL v2+",
+
+    .instantiate = midichannelize_instantiate,
+    .cleanup     = midichannelize_cleanup,
+
+    .get_parameter_count = midichannelize_get_parameter_count,
+    .get_parameter_info  = midichannelize_get_parameter_info,
+    .get_parameter_value = midichannelize_get_parameter_value,
+
+    .get_midi_program_count = NULL,
+    .get_midi_program_info  = NULL,
+
+    .set_parameter_value = midichannelize_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    = midichannelize_process,
+
+    .get_state = NULL,
+    .set_state = NULL,
+
+    .dispatcher = NULL
+};
+
+// -----------------------------------------------------------------------
+
+void carla_register_native_plugin_midichannelize(void);
+
+void carla_register_native_plugin_midichannelize(void)
+{
+    carla_register_native_plugin(&midichannelizeDesc);
+}
+
+// -----------------------------------------------------------------------