GEOnormedTangent

Standardised direction vector of a tangent.

With this routine the standardised direction vector of a tangent in the circle is calculated. Has input_left the value TRUE, then the tangent of the point (input_x, input_y) on the circle points to the left, but to the right.

Parametre

input_cx (const stands in) [IN]

input_cy (const stands in) [IN]

Centre of the circle

input_x (const stands in) [IN]

input_y (const stands in) [IN]

Sharp on the circle where the tangent touches the circle.

input_left (const BOOLEAN) [IN]

With value TRUE the tangent points to the left, but to the right.

output_x (stands in *) [IN / OUT]

output_y (stands in *) [IN / OUT]

The standardised direction vector.

Result

(BOOLEAN) [OUT]

FALSE if point Centre of the circle is, but TRUE.

Declaration

#include "basic.h"

BOOLEAN DLLENTRY GEOnormedTangent (

const stands in input_cx,

const stands in input_cy,

const stands in input_x,

const stands in input_y,

const BOOLEAN left,

stand in * output_x,

stand in * output_y

);