ignition/line_inter.m

   1 function [x,y]=line_inter(x1,y1,x2,y2,x3,y3,x4,y4)
   2
   3 % Volodymyr Kondratenko           August 2011
   4
   5 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   6
   7 % finds the distance from (x3,y3) to line through (x1,y1) and (x2,y2)
   8
   9 m21=(y2-y1)/(x2-x1);
  10 m43=(y4-y3)/(x4-x3);
  11 x = (x1*m21-x3*m43-y1+y3)/(m21-m43);
  12 y = y1 + m21*(x-x1);
  13
  14 if (x2==x1)
  15     x=x1;
  16     m21=0;
  17 y = y3 + m43*(x-x3);
  18
  19 end
  20
  21 if (x3==x4)
  22     x=x3;
  23     m43=0;
  24 y = y1 + m21*(x-x1);
  25
  26 end
  27
  28 end
  29