IParameterFunctionName Class Reference

Edit controller component interface extension: Vst::IParameterFunctionName. More...

#include <ivstparameterfunctionname.h>

Inheritance diagram for IParameterFunctionName:

Public Member Functions
virtual tresult	getParameterIDFromFunctionName (UnitID unitID, FIDString functionName, ParamID &paramID)=0
	Gets for the given unitID the associated paramID to a function Name.
Public Member Functions inherited from FUnknown
virtual tresult	queryInterface (const TUID _iid, void **obj)=0
virtual uint32	addRef ()=0
virtual uint32	release ()=0

Static Public Attributes
static const FUID	iid
Static Public Attributes inherited from FUnknown
static const FUID	iid

Detailed Description

Edit controller component interface extension: Vst::IParameterFunctionName.

• [plug imp]
• [extends IEditController]
• [released: 3.7.0]
• [optional]

This interface allows the host to get a parameter associated to a specific meaning (a functionName) for a given unit. The host can use this information, for example, for drawing a Gain Reduction meter in its own UI. In order to get the plain value of this parameter, the host should use the IEditController::normalizedParamToPlain. The host can automatically map parameters to dedicated UI controls, such as the wet-dry mix knob or Randomize button.

Example

//------------------------------------------------------------------------
// here an example of how a VST3 plug-in could support this IParameterFunctionName interface.
// we need to define somewhere the iids:

in MyController class declaration
class MyController : public Vst::EditController, public Vst::IParameterFunctionName
{
    ...
    tresult PLUGIN_API getParameterIDFromFunctionName (UnitID unitID, FIDString functionName,
                                                    Vst::ParamID& paramID) override;
    ...

    OBJ_METHODS (MyController, Vst::EditController)
    DEFINE_INTERFACES
        ...
        DEF_INTERFACE (Vst::IParameterFunctionName)
    END_DEFINE_INTERFACES (Vst::EditController)
    DELEGATE_REFCOUNT (Vst::EditController)
    ...
}

#include "ivstparameterfunctionname.h"
namespace Steinberg {
    namespace Vst {
        DEF_CLASS_IID (IParameterFunctionName)
    }
}

//------------------------------------------------------------------------
tresult PLUGIN_API MyController::getParameterIDFromFunctionName (UnitID unitID, FIDString
functionName, Vst::ParamID& paramID)
{
    using namespace Vst;

    paramID = kNoParamId;

    if (unitID == kRootUnitId && FIDStringsEqual (functionName, kCompGainReduction))
        paramID = kMyGainReductionId;

    return (paramID != kNoParamId) ? kResultOk : kResultFalse;
}

//--- a host implementation example: --------------------
...
FUnknownPtr<Vst::IParameterFunctionName> functionName (mEditController->getIEditController ());
if (functionName)
{
    Vst::ParamID paramID;
    if (functionName->getParameterIDFromFunctionName (kRootUnitId,
                                                      Vst::FunctionNameType::kCompGainReduction, paramID) == kResultTrue)
    {
        // paramID could be cached for performance issue
        ParamValue norm = mEditController->getIEditController ()->getParamNormalized (paramID);
        ParamValue plain = mEditController->getIEditController ()->normalizedParamToPlain (paramID, norm);
        // plain is something like -6 (-6dB)
    }
}

Member Function Documentation

virtual tresult getParameterIDFromFunctionName ( UnitID  unitID, FIDString  functionName, ParamID &  paramID  )

pure virtual

Gets for the given unitID the associated paramID to a function Name.

Returns kResultFalse when no found parameter (paramID is set to kNoParamId in this case).

Member Data Documentation

const FUID iid

static