Definition: <m>sum{}{}{f®}</m>
f(x) is analytical convolution for a triangle with Cauchy kernel [McCormack and Sherstyuk 1998]
r - distance to a skeleton point
Call: hfConvTriangle(x,vect,S,T);
Parameters:
x - point coordinates
vect - coordinate array for vertices of triangles (9 elements for each)
S - array of kernel width control parameters for each triangle
T - threshold
Test file: convtri.hf