Basic Code The basic code is not too bad. Here is my segment intersection routine:int intersect( double px0,double py0,double px1,double py1, double px2,double py2,double px3,double py3, double *px,double *py) { double det,s,t; // Test if co-linear det=(px3-px2)*(py0-py1)-(px0-px1)*(py3-py2);...