pointer to 3d array

Question

i have a 3D array and i want to get IntPtr to point on it so here what i did ..can anyone tell me if it's right or not...

fixed (Int16* mypointer = &myvolume[0, 0, 0])
{
     //then i cast mypointer as IntPtr
}

notice that myvolume is of dimensions 200 x 100 x 100

You do understand that the IntPtr won't be valid after you exit the `fixed` block, right? — Joe White, Mar 15 '11 at 12:49
yes i know that's why in inserted all my code inside the Fixed block, thanks for your concern — Sara S., Mar 15 '11 at 13:14

score 3 · Accepted Answer · answered Mar 15 '11 at 12:42

3

Are you sure that what you really want is an unsafe pointer? Using pointers like this is very very rare in C# land.

Eric Lippert recently wrote about a simple class that offers some of the behavior of pointers, without resorting to unsafe code. You might consider extending it to work with your multidimensional arrays.

answered Mar 15 '11 at 12:42

Chris Pitman

THanks Chris ,actually i'm using some vtk algorithms that requires a pointer to my volume that's why i'm using pointers, i'll check this article, Thanks for your effort – Sara S. Mar 15 '11 at 13:15
It's not as rare as you'd think. Pointer arithmetic is by far the fastest way to iterate over arrays like this and you'll find a lot of this kind of code in performance critical apps. – MattDavey Mar 15 '11 at 13:41
@MattDavey I agree there are places for it, and have used it myself for image manipulation routines. The danger is that programmers new to "high performance" computing in C# will jump right to pointers without trying/profiling the standard C# solutions. – Chris Pitman Mar 15 '11 at 13:53
actually i used it before with another SDKs but i was troubleshooting a problem so i wanted to make sure if i use it appropriately :) – Sara S. Mar 15 '11 at 14:14

1 Answers1