houdini vex simple polygon

float width = chf("width");
float depth = chf("depth");

float halfWidth = width * 0.5;
float halfDepth = depth * 0.5;

vector v0 = set( halfWidth, 0,  halfDepth);
vector v1 = set(-halfWidth, 0,  halfDepth);
vector v2 = set(-halfWidth, 0, -halfDepth);
vector v3 = set( halfWidth, 0, -halfDepth);

int pnt0 = addpoint(0, v0);
int pnt1 = addpoint(0, v1);
int pnt2 = addpoint(0, v2);
int pnt3 = addpoint(0, v3);

int prim0 = addprim(0, "poly");

int vert0 = addvertex(0, prim0, pnt0);
int vert1 = addvertex(0, prim0, pnt1);
int vert2 = addvertex(0, prim0, pnt2);
int vert3 = addvertex(0, prim0, pnt3);