function [I_ST] = DEMCEM_ST(Np_1D,dx,dy)
%% Splitting the original rectangle in triangles for DEMCEM
% GEOMETRY
r1 = [0, 0,0]';
r2 = [dx,0,0]';
r3 = [dx,dy,0]';
r4 = [0 ,dy,0]';

% Evaluate ST
[I_T1_T1] = DIRECT_WS_ST_RWG(r1,r2,r3,Np_1D);
[I_T1_T2] = DIRECT_WS_EA_RWG(r1,r3,r2,r4,Np_1D);
[I_T2_T1] = DIRECT_WS_EA_RWG(r1,r3,r4,r2,Np_1D);
[I_T2_T2] = DIRECT_WS_ST_RWG(r1,r3,r4,Np_1D);

I_ST = I_T1_T1 + I_T1_T2 + I_T2_T1 + I_T2_T2;
