Allocate memory question

Hallo,

Is there a difference between doing this:

Code:

   // Allocate memory for the list of directions.
   CVector4 *direction = new CVector4[width * height];

And:

Code:

   // Allocate memory for the list of directions.
   CVector4 direction[width * height];

Thanks

Yes. The first one is dynamic allocating (so called heap memory) and requires deleting after use. Otherwise it will produce a memory leek. The second one is freed automatically and the reserved memory is on the stack.

Ah, thank you

Ok, I have a problem here, relating to the above question

Code:

    // Load the direction list
    Vector3D myList = generateRayDirections(400,400,0);


// A function for generating a ray
// Note: this is not a part of Engine::
Vector3D generateRayDirections(int width, int hight, int depth)
{
    // An array for holding all the directions for all the rays which 
    // later will be created
    Vector3D *directionTable = new Vector3D[width * hight];
    
    // Variables for holding half the width and hight.
    // Is used to set the camera at the center of the screen
    float halfWidth = (float)(width/2);
    float halfHight = (float)(hight/2);
    
    
    // We loop through all the pixels starting from left uper
    // corner and move to the right. Then a direction is created 
    // for each of them, making it easy to acces them later
    for (int y = 0; y < hight; y++)
    {
        for (int x = 0; x < width; x++)
        {
            // Assign direction
               // reference which number of the array
               // Create a vector with the direction
               // Normalize the vector
               // Add a vector with the direction to the array
        }
    }
    
    return directionTable;
}

Here is the errors:
RayTracer.cpp In function `Vector3D generateRayDirections(int, int, int)':
RayTracer.cpp conversion from `Vector3D*' to non-scalar type `Vector3D' requested

The return type of generateRayDirections indicates that the function returns a single Vector3D.

I have been trying to fix this for a while now, but no sucsess so far. So could anyone please give me a helping hand?

Thanks

You should change the return type to Vector3D* instead, and remember to delete[] when you are done.