How to create the FMOD_STUDIO_EVENTDESCRIPTION array for use in FMOD_Studio_Bank_GetEventList() (FMOD Studio C API)

FMOD Studio
1

I have loaded a bank and want to iterate through all the events it contains. From the documentation, it looks like I should use FMOD_Studio_Bank_GetEventCount() to get the count of the events and use this count to create a buffer to pass to FMOD_Studio_Bank_GetEventList() to retrieve an array of FMOD_STUDIO_EVENTDESCRIPTIONs.

However, FMOD_STUDIO_EVENTDESCRIPTION is defined in fmod_studio_common.h as

typedef struct FMOD_STUDIO_EVENTDESCRIPTION FMOD_STUDIO_EVENTDESCRIPTION;

i.e. an incomplete type. Therefore the compiler gives an error when trying to use

sizeof(FMOD_STUDIO_EVENTDESCRIPTION)

or

FMOD_STUDIO_EVENTDESCRIPTION array[count];

because it can’t determine the size of the FMOD_STUDIO_EVENTDESCRIPTION type.

So how are people creating buffers/arrays to use with this function? Am I missing something in the documentation?

Thanks, Jim

2

Hi Jim,

This is more of a C/C++ type question to do with allocating the memory needed for the array of event descriptions.

int i;
sfxBank->getEventCount(&i);
const int list = i;
FMOD::Studio::EventDescription** eventList = new FMOD::Studio::EventDescription*[list];
sfxBank->getEventList(eventList, i, &i);

You need to make the event description array and array of pointers for it to work.

Thanks,
Richard

3

Hi Richard, Thanks for your answer, however I am using the C API, not the C++ API. In the C++ headers the EventDescription class is fully declared so 

new FMOD::Studio::EventDescription*[list];
will allocate the required memory for the array. In the C headers, the FMOD_STUDIO_EVENTDESCRIPTION type is not fully declared, therefore there is no way for the compiler to know the size of the type, and therefore no way to allocate the memory.

4

Hi Jim,

Sorry, missed that part. Yes, there’s no “new” in C so you can use this instead:

FMOD_STUDIO_EVENTDESCRIPTION** eventList = (FMOD_STUDIO_EVENTDESCRIPTION**)malloc(sizeof(FMOD_STUDIO_EVENTDESCRIPTION*) * i);
1 Like
5

Ah, I see. It is only required to allocation memory for the pointers to the descriptions, not the descriptions themselves. Thanks!