Declare pointer inside a function that is called several times

Question

I would like to know whether or not I can do this with a function Idle() which is called several times in an opengl program.Is this OK or will I get a memory leak?

void Idle()
{
    //PXCPointF32 is a struct
    PXCPointF32 *uvmap=0;

    uvmap=new PXCPointF32[640*480];
    if(uvmap!=NULL)
    {
       //do some processing
       //fill uvmap values
    }

    if (uvmap) 
    {
        delete[] uvmap;
        uvmap=NULL;
    }
}

Answer 1

The code should work but its not optimal:

void Idle()
{
    //PXCPointF32 is a struct
    PXCPointF32 *uvmap=0; // why initialize to 0 only to replace its value?

    uvmap=new PXCPointF32[640*480];
    if(uvmap!=NULL)
    {
       //do some processing
       //fill uvmap values
    }

    if (uvmap) // no need to test for null before deleting
    {
        delete[] uvmap;
        uvmap=NULL; // no point setting to NULL because its local
    }
}

Instead you could do:

void Idle()
{
    // set it directly
    PXCPointF32* uvmap = new PXCPointF32[640*480];

    if(uvmap)
    {
       //do some processing
       //fill uvmap values
    }

    delete[] uvmap; // don't bother checking for null (delete[] does that)
}

You might also want to consider a smart pointer to clean up the memory in case of an exception:

void Idle()
{
    // set it directly
    std::unique_ptr<PXCPointF32[]> uvmap(new PXCPointF32[640*480]);

    if(uvmap)
    {
       //do some processing
       //fill uvmap values
    }

    // no delete[] here
}