Using Matlab's inbuilt class 'delaunayTriangulation' in mex

Question

I would like to use Matlab's delaunayTriangulation class to construct the triangulation of a set of points in 3D, P [nx3 matrix], within a mex function.

In Matlab,

DT = delaunayTriangulation(P)

computes the triangulation with 'Points' & 'ConnectivityList' as the class properties of DT.

How do I perform the same operation within a mex file?

void mexFunction(int nlhs, mxArray* plhs[], int nrhs, const mxArray* prhs[]) { 
....

int n;
int elements = n*3;

double* P_ptr; /*contains 3D coordinates*/
P_ptr = mxMalloc(elements * sizeof(double));

/* fill up P_ptr with coordinates */

mxArray *DT, *P;

mxSetPr(P,P_ptr); /* Set P_ptr to mxArray P */
mxSetM(P, n);
mxSetN(P, 3);

mexCallMATLAB(1, &DT, 1, &P, "delaunayTriangulation");

....

}

Is it the right way to go? Also, if the code above is right, how do I access the class properties(Points, ConnectivityList) from output mxArray *DT?

Thanks

Edit: Changed DT to &DT for correctness in the code above. Also, based on Sam's solution, I was able to access the property (eg "ConnectivityList") by the following code:

mxArray* variable_name = mxGetProperty(DT,0,"ConnectivityList");

Answer 1

你应该能够使用mxGetProperty访问一个对象的属性mxArray 。