Thread: Multi-dimensional Dynamic Arrays

I'm trying to create a function that converts a custom structure - Spline - to a 2-dimension array of doubles. The problem is that although the function works fine and stores the correct values in the 2-dimension array p, it seems to store them localy. That is, if i try to access for example p[0][0] within the funcion, i can do it, however outside the function i just get a memory error, as if i was accessing the outer space (which i probably am). Can anyone help me out here?

Example:

Code:

double **knots;

void SplineToVector(const Spline spline, double **p, int *size)
{
	int i, j;
	*size = spline.sections_list_size + 3;
	p = new double*[*size];
	for(i = 0; i < spline.sections_list_size; i++)
	{
		p[i] = new double[3];
		for(j = 0; j < 3; j++)
			p[i][j] = spline.sections_list[i].k_matrix[0][j];
	}
	for(i = 1; i < 4; i++)
	{
		p[spline.sections_list_size - 1 + i] = new double[3];
		for(j = 0; j < 3; j++)
			p[spline.sections_list_size - 1 + i][j] = spline.sections_list[spline.sections_list_size - 1].k_matrix[i][j];
	}
	printf("Sample Knot: %f\n", p[0][0];  // NO ERROR HERE
}

void main()
{
	Spline example;
	//Other stuff related to Spline
	SplineToVector(example, knots, n_knots);
	printf("Sample Knot: %f\n", knots[0][0];  // MEMORY ERROR
}

Worked, thnx.