Add midi-transpose plugin

source/backend/native/midi-transpose.c

@@ -0,0 +1,193 @@
+/*
+ * Carla Native Plugins
+ * Copyright (C) 2012-2013 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 GPL.txt file
+ */
+
+#include "CarlaNative.h"
+#include "CarlaMIDI.h"
+
+#include <stdlib.h>
+
+typedef struct _MidiTransposeHandle {
+    HostDescriptor* host;
+    int octaves;
+} MidiTransposeHandle;
+
+static PluginHandle midiTranspose_instantiate(const PluginDescriptor* _this_, HostDescriptor* host)
+{
+    MidiTransposeHandle* const handle = (MidiTransposeHandle*)malloc(sizeof(MidiTransposeHandle));
+
+    if (handle != NULL)
+    {
+        handle->host    = host;
+        handle->octaves = 0;
+        return handle;
+    }
+
+    return NULL;
+
+    // unused
+    (void)_this_;
+}
+
+#define handlePtr ((MidiTransposeHandle*)handle)
+
+static void midiTranspose_cleanup(PluginHandle handle)
+{
+    free(handlePtr);
+}
+
+static uint32_t midiTranspose_get_parameter_count(PluginHandle handle)
+{
+    return 1;
+
+    // unused
+    (void)handle;
+}
+
+const Parameter* midiTranspose_get_parameter_info(PluginHandle handle, uint32_t index)
+{
+    if (index != 0)
+        return NULL;
+
+    static Parameter param;
+
+    param.name  = "Octaves";
+    param.unit  = NULL;
+    param.hints = PARAMETER_IS_ENABLED|PARAMETER_IS_AUTOMABLE|PARAMETER_IS_INTEGER;
+    param.ranges.def = 0.0f;
+    param.ranges.min = -8.0f;
+    param.ranges.max = 8.0f;
+    param.ranges.step = 1.0f;
+    param.ranges.stepSmall = 1.0f;
+    param.ranges.stepLarge = 1.0f;
+    param.scalePointCount = 0;
+    param.scalePoints     = NULL;
+
+    return &param;
+
+    // unused
+    (void)handle;
+}
+
+static float midiTranspose_get_parameter_value(PluginHandle handle, uint32_t index)
+{
+    if (index != 0)
+        return 0.0f;
+
+    return (float)handlePtr->octaves;
+}
+
+static void midiTranspose_set_parameter_value(PluginHandle handle, uint32_t index, float value)
+{
+    if (index != 0)
+        return;
+
+    handlePtr->octaves = (int)value;
+}
+
+static void midiTranspose_process(PluginHandle handle, float** inBuffer, float** outBuffer, uint32_t frames, uint32_t midiEventCount, const MidiEvent* midiEvents)
+{
+    HostDescriptor* const host = handlePtr->host;
+    const int octaves = handlePtr->octaves;
+    MidiEvent tmpEvent;
+
+    for (uint32_t i=0; i < midiEventCount; i++)
+    {
+        const MidiEvent* const midiEvent = &midiEvents[i];
+
+        const uint8_t status = MIDI_GET_STATUS_FROM_DATA(midiEvent->data);
+
+        if (status == MIDI_STATUS_NOTE_OFF || status == MIDI_STATUS_NOTE_ON)
+        {
+            int note  = midiEvent->data[1];
+            int rnote = note + octaves*12;
+
+            if (rnote < 0 || rnote >= MAX_MIDI_NOTE)
+                continue;
+
+            tmpEvent.port    = midiEvent->port;
+            tmpEvent.time    = midiEvent->time;
+            tmpEvent.data[0] = midiEvent->data[0];
+            tmpEvent.data[1] = rnote;
+            tmpEvent.data[2] = midiEvent->data[2];
+
+            host->write_midi_event(host->handle, &tmpEvent);
+        }
+        else
+            host->write_midi_event(host->handle, &midiEvents[i]);
+    }
+
+    return;
+
+    // unused
+    (void)inBuffer;
+    (void)outBuffer;
+    (void)frames;
+}
+
+#undef handlePtr
+
+// -----------------------------------------------------------------------
+
+static const PluginDescriptor midiTransposeDesc = {
+    .category  = PLUGIN_CATEGORY_NONE,
+    .hints     = PLUGIN_IS_RTSAFE,
+    .audioIns  = 0,
+    .audioOuts = 0,
+    .midiIns   = 1,
+    .midiOuts  = 1,
+    .parameterIns  = 1,
+    .parameterOuts = 0,
+    .name      = "MIDI Transpose",
+    .label     = "midiTranspose",
+    .maker     = "falkTX",
+    .copyright = "GNU GPL v2+",
+
+    .instantiate = midiTranspose_instantiate,
+    .cleanup     = midiTranspose_cleanup,
+
+    .get_parameter_count = midiTranspose_get_parameter_count,
+    .get_parameter_info  = midiTranspose_get_parameter_info,
+    .get_parameter_value = midiTranspose_get_parameter_value,
+    .get_parameter_text  = NULL,
+
+    .get_midi_program_count = NULL,
+    .get_midi_program_info  = NULL,
+
+    .set_parameter_value = midiTranspose_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    = midiTranspose_process
+};
+
+// -----------------------------------------------------------------------
+
+void carla_register_native_plugin_midiTranspose()
+{
+    carla_register_native_plugin(&midiTransposeDesc);
+}
+
+// -----------------------------------------------------------------------