Implementation of the SWAP subroutine written in R

Checks to see if triangle P-V2-V1 and V3-V1-V2 need to swap common edge

Usage

swapR(x1, y1, x2, y2, x3, y3, xp, yp)

Arguments

x1

X coordinate of V1

y1

Y coordinate of V1

x2

X coordinate of V2

y2

Y coordinate of V2

x3

X coordinate of V3

y3

Y coordinate of V3

xp

X coordinate of P

yp

Y coordinate of P