Is Casey checking two times the DirectSoundCreate? Like, checking all the function, and checking with those parameters in specific? What is going on with this statement?
1 2 3 4 | if(DirectSoundCreate && SUCCEEDED(DirectSoundCreate(0, &directSound, 0)))
{
...
}
|
DirectSoundCreate is a pointer (function pointer).
"DirectSoundCreate" tests if pointer is not NULL. It is equivalent to following expression "DirectSoundCreate != NULL".
"SUCCEEDED(DirectSoundCreate(0, &directSound, 0))" is calling this function pointer and passing result to SUCCEEDED macro. This macro expands to something like this: "DirectSoundCreate(0, &directSound, 0) == S_OK".
So if statement executes following:
"DirectSoundCreate" tests if pointer is not NULL. It is equivalent to following expression "DirectSoundCreate != NULL".
"SUCCEEDED(DirectSoundCreate(0, &directSound, 0))" is calling this function pointer and passing result to SUCCEEDED macro. This macro expands to something like this: "DirectSoundCreate(0, &directSound, 0) == S_OK".
So if statement executes following:
1 2 3 4 5 6 7 | if (DirectSoundCreate != NULL)
{
if (DirectSoundCreate(0, &directSound, 0) == S_OK)
{
...
}
}
|