diaedg Interface

interface
public function diaedg(x0, y0, x1, y1, x2, y2, x3, y3) result(rst)

Arguments

Type IntentOptional Attributes Name
real(kind=real64), intent(in) :: x0

The x-coordinate of vertex 0.
real(kind=real64), intent(in) :: y0

The y-coordinate of vertex 0.
real(kind=real64), intent(in) :: x1

The x-coordinate of vertex 1.
real(kind=real64), intent(in) :: y1

The y-coordinate of vertex 1.
real(kind=real64), intent(in) :: x2

The x-coordinate of vertex 2.
real(kind=real64), intent(in) :: y2

The y-coordinate of vertex 2.
real(kind=real64), intent(in) :: x3

The x-coordinate of vertex 3.
real(kind=real64), intent(in) :: y3

The y-coordinate of vertex 3.

Return Value integer(kind=int32)

The edge.

Description

Chooses a diagonal edge.

The routine determines whether 0--2 or 1--3 is the diagonal edge that should be chosen, based on the circumcircle criterion, where (X0,Y0), (X1,Y1), (X2,Y2), (X3,Y3) are the vertices of a simple quadrilateral in counterclockwise order.