polyUtil.h File Reference

#include "definitions.h"

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Functions
Real	area (Real A[2], Real B[2], Real C[2])
Int	pointLeftLine (Real A[2], Real B[2], Real P[2])
Int	pointLeft2Lines (Real A[2], Real B[2], Real C[2], Real P[2])

Function Documentation

area()

Real area	(	Real	A[2],
		Real	B[2],
		Real	C[2]
	)

Definition at line 43 of file polyUtil.cc.

{
  Real Bx, By, Cx, Cy;
  Bx = B[0] - A[0];
  By = B[1] - A[1];
  Cx = C[0] - A[0];
  Cy = C[1] - A[1];
  return Bx*Cy - Cx*By;
 
/*  return (B[0]-A[0])*(C[1]-A[1]) - (C[0]-A[0])*(B[1]-A[1]);*/
}

Referenced by pointLeft2Lines(), and pointLeftLine().

pointLeft2Lines()

Int pointLeft2Lines	(	Real	A[2],
		Real	B[2],
		Real	C[2],
		Real	P[2]
	)

Definition at line 78 of file polyUtil.cc.

{
  Int C_left_AB = (area(A, B, C)>0);
  Int P_left_AB = (area(A, B, P)>0);
  Int P_left_BC = (area(B, C, P)>0);
 
  if(C_left_AB)
    {
      return (P_left_AB && P_left_BC);
    }
  else
    return  (P_left_AB || P_left_BC);
}

Referenced by MC_partitionY(), and partitionY().

pointLeftLine()

Int pointLeftLine	(	Real	A[2],
		Real	B[2],
		Real	P[2]
	)

Definition at line 64 of file polyUtil.cc.

{
  if(area(A, B, P) >0) return 1;
  else return 0;
}