Remarks
Sets the name of a specific function of the external custom DSP.
As you may know, the GetProcAddress Windows API allows retrieving the address of an exported function from a specified dynamic-link library (DLL) file previously loaded through the LoadLibrary Windows API: in a very similar way, the CustomDSP.ExternalSetFunction method allows retrieving the address of an exported function from a specified dynamic-link library (DLL) file previously loaded through the CustomDSP.ExternalLoad method. Through this mechanism you can set the callback function that will effectively manage the DSP effect, retrieving/setting DSP effect's parameters, asking the DSP to display its own user interface (also known as "Editor") and also send your own custom commands to the DSP.
For further details about managing a custom DSP effect refer to the How to manage custom DSP effects section.
For further details about methods related to the use of custom DSP effects refer to the CustomDSPs class.
Syntax
Parameter
|
Description
|
|
|
nIdDsp
|
Unique identifier of the custom DSP
|
nFunctionType
|
Type of function to set.
Supported values are the following:
Mnemonic constant
|
Value
|
Meaning
|
DSP_FUNC_CALLBACK
|
0
|
Sets the callback function containing the code that will effectively modify original WAV PCM data. Remember that callback functions must be as fast as possible in order to avoid slowing down overall performances.
The Visual C++ definition of an external callback function is as follows:
void WINAPI MyCustomCallback (
void *bufferSamples,
DWORD bufferSamplesLength,
DWORD nUserData
);
where
bufferSamples
|
Pointer to the buffer containing WAV PCM samples to be processed by the DSP in one of the following formats:
8-bit samples are unsigned
16-bit samples are signed
32-bit floating-point samples can range from -1 to +1: note that they are not clipped so they could be outside the mentioned range.
You can instruct the DSP using 32-bit floating-point samples only through the CustomDSP.UseFloatSamples method.
|
bufferSamplesLength
|
The length in bytes of the buffer above
|
nUserData
|
User specific data
|
|
DSP_FUNC_PARAMS_GET
|
1
|
Sets the function used to obtain current parameters from the external DSP
|
DSP_FUNC_PARAMS_SET
|
2
|
Sets the function used to set parameters to the external DSP
|
DSP_FUNC_COMMAND_SEND
|
3
|
Sets the function used to send your own custom commands to the external DSP
|
DSP_FUNC_EDITOR_DISPLAY
|
4
|
Sets the function used to display the editor (user interface) of the external DSP: the availability of a user interface is not mandatory
|
DSP_FUNC_EDITOR_GET_INFO
|
5
|
Sets the function used to obtain information about the editor (user interface) of the external DSP
|
|
strFunctionName
|
Name of the function exported by the dynamic-link library (DLL)
|
Return value
Value
|
Meaning
|
|
|
Negative value
|
An error occurred (see the LastError property for further error details)
|
enumErrorCodes.ERR_NOERROR (0)
|
The method call was successful.
|
|
