Implement LV2 ControlInputPort change request feature

Signed-off-by: falkTX <falktx@falktx.com>

source/backend/plugin/CarlaPluginLV2.cpp

@@ -188,6 +188,7 @@ enum CarlaLv2Features {
     kFeatureIdWorker,
     kFeatureIdInlineDisplay,
     kFeatureIdMidnam,
+    kFeatureIdCtrlInPortChangeReq,
     kFeatureCountPlugin,
     // UI features
     kFeatureIdUiDataAccess = kFeatureCountPlugin,
@@ -835,6 +836,9 @@ public:
         if (fFeatures[kFeatureIdMidnam] != nullptr && fFeatures[kFeatureIdMidnam]->data != nullptr)
             delete (LV2_Midnam*)fFeatures[kFeatureIdMidnam]->data;
 
+        if (fFeatures[kFeatureIdCtrlInPortChangeReq] != nullptr && fFeatures[kFeatureIdCtrlInPortChangeReq]->data != nullptr)
+            delete (LV2_ControlInputPort_Change_Request*)fFeatures[kFeatureIdCtrlInPortChangeReq]->data;
+
         for (uint32_t i=0; i < kFeatureCountAll; ++i)
         {
             if (fFeatures[i] != nullptr)
@@ -6150,6 +6154,20 @@ public:
 
     // -------------------------------------------------------------------
 
+    LV2_ControlInputPort_Change_Status handleCtrlInPortChangeReq(const uint32_t index, const float value)
+    {
+        CARLA_SAFE_ASSERT_RETURN(index < fRdfDescriptor->PortCount, LV2_CONTROL_INPUT_PORT_CHANGE_ERR_INVALID_INDEX);
+        CARLA_SAFE_ASSERT_RETURN(fParamBuffers != nullptr, LV2_CONTROL_INPUT_PORT_CHANGE_ERR_UNKNOWN);
+
+        const float fixedValue = pData->param.getFixedValue(index, value);
+        fParamBuffers[index] = fixedValue;
+
+        CarlaPlugin::setParameterValueRT(index, fixedValue, 0, true);
+        return LV2_CONTROL_INPUT_PORT_CHANGE_SUCCESS;
+    }
+
+    // -------------------------------------------------------------------
+
     void handleExternalUIClosed()
     {
         CARLA_SAFE_ASSERT_RETURN(fUI.type == UI::TYPE_EXTERNAL,);
@@ -6791,6 +6809,10 @@ public:
         midnam->handle = this;
         midnam->update = carla_lv2_midnam_update;
 
+        LV2_ControlInputPort_Change_Request* const portChangeReq = new LV2_ControlInputPort_Change_Request;
+        portChangeReq->handle = this;
+        portChangeReq->request_change = carla_lv2_ctrl_in_port_change_req;
+
         // ---------------------------------------------------------------
         // initialize features (part 2)
 
@@ -6868,6 +6890,9 @@ public:
         fFeatures[kFeatureIdMidnam]->URI  = LV2_MIDNAM__update;
         fFeatures[kFeatureIdMidnam]->data = midnam;
 
+        fFeatures[kFeatureIdCtrlInPortChangeReq]->URI  = LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI;
+        fFeatures[kFeatureIdCtrlInPortChangeReq]->data = portChangeReq;
+
         // ---------------------------------------------------------------
         // initialize features (part 3)
 
@@ -8176,6 +8201,18 @@ private:
         ((CarlaPluginLV2*)handle)->handleMidnamUpdate();
     }
 
+    // -------------------------------------------------------------------
+    // ControlInputPort change request Feature
+
+    static LV2_ControlInputPort_Change_Status carla_lv2_ctrl_in_port_change_req(
+        LV2_ControlInputPort_Change_Request_Handle handle, uint32_t index, float value)
+    {
+        CARLA_SAFE_ASSERT_RETURN(handle != nullptr, LV2_CONTROL_INPUT_PORT_CHANGE_ERR_UNKNOWN);
+        carla_stdout("carla_lv2_ctrl_in_port_change_req(%p, %u, %f)", handle, index, value);
+
+        return ((CarlaPluginLV2*)handle)->handleCtrlInPortChangeReq(index, value);
+    }
+
     // -------------------------------------------------------------------
     // External UI Feature
 

source/includes/lv2/control-input-port-change-request.h

@@ -0,0 +1,84 @@
+/*
+  LV2 ControlInputPort change request extension
+  Copyright 2020 Filipe Coelho <falktx@falktx.com>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/**
+   @file control-input-port-change-request.h
+   C header for the LV2 ControlInputPort change request extension <http://kx.studio/ns/lv2ext/control-input-port-change-request>.
+*/
+
+#ifndef LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_H
+#define LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_H
+
+#include "lv2.h"
+
+#define LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI    "http://kx.studio/ns/lv2ext/control-input-port-change-request"
+#define LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_PREFIX LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI "#"
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#else
+#include <stdbool.h>
+#endif
+
+/** A status code for LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI functions. */
+typedef enum {
+	LV2_CONTROL_INPUT_PORT_CHANGE_SUCCESS           = 0,  /**< Completed successfully. */
+	LV2_CONTROL_INPUT_PORT_CHANGE_ERR_UNKNOWN       = 1,  /**< Unknown error. */
+	LV2_CONTROL_INPUT_PORT_CHANGE_ERR_INVALID_INDEX = 2   /**< Failed due to invalid port index. */
+} LV2_ControlInputPort_Change_Status;
+
+/**
+ *  Opaque handle for LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI feature.
+ */
+typedef void* LV2_ControlInputPort_Change_Request_Handle;
+
+/**
+ * On instantiation, host must supply LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI feature.
+ * LV2_Feature::data must be pointer to LV2_ControlInputPort_Change_Request.
+*/
+typedef struct _LV2_ControlInputPort_Change_Request {
+    /**
+     *  Opaque host data.
+     */
+    LV2_ControlInputPort_Change_Request_Handle handle;
+
+    /**
+     * request_change()
+     *
+     * Ask the host to change a plugin's control input port value.
+     * Parameter handle MUST be the 'handle' member of this struct.
+     * Parameter index is port index to change.
+     * Parameter value is the requested value to change the control port input to.
+     *
+     * Returns status of the request.
+     * The host may decline this request, if e.g. it is currently automating this port.
+     *
+     * The plugin MUST call this function during run().
+     */
+    LV2_ControlInputPort_Change_Status (*request_change)(LV2_ControlInputPort_Change_Request_Handle handle,
+                                                         uint32_t index,
+                                                         float value);
+
+} LV2_ControlInputPort_Change_Request;
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_H */

source/utils/CarlaLv2Utils.hpp

@@ -72,6 +72,8 @@
 #include "lv2/lv2_programs.h"
 #include "lv2/lv2_rtmempool.h"
 
+#include "lv2/control-input-port-change-request.h"
+
 #include "lilv/lilvmm.hpp"
 #include "sratom/sratom.h"
 #include "lilv/config/lilv_config.h"
@@ -3184,6 +3186,8 @@ bool is_lv2_feature_supported(const LV2_URI uri) noexcept
         return true;
     if (std::strcmp(uri, LV2_BUF_SIZE__powerOf2BlockLength) == 0)
         return true;
+    if (std::strcmp(uri, LV2_CONTROL_INPUT_PORT_CHANGE_REQUEST_URI) == 0)
+        return true;
     if (std::strcmp(uri, LV2_CORE__hardRTCapable) == 0)
         return true;
     if (std::strcmp(uri, LV2_CORE__inPlaceBroken) == 0)