Inside Macintosh: 3D Graphics Programming With QuickDraw 3D /

Chapter 20 - QuickDraw 3D Mathematical Utilities / QuickDraw 3D Mathematical Utilities Reference

QuickDraw 3D Mathematical Utilities / Determining Point Relative Ratios

Q3Point3D_RRatio

You can use the Q3Point3D_RRatio function to find a point lying between two given three-dimensional points that is at a desired distance ratio from one of those points.

TQ3Point3D *Q3Point3D_RRatio (
const TQ3Point3D *p1, 
const TQ3Point3D *p2, 
float r1, 
float r2, 
TQ3Point3D *result);

p1

A three-dimensional point.

p2

A three-dimensional point.

r1

A floating-point number.

r2

A floating-point number.

result

On exit, the three-dimensional point that is at a desired distance ratio from p1 along the line segment between p1 and p2.

DESCRIPTION

The Q3Point3D_RRatio function returns, as its function result and in the result parameter, the three-dimensional point that lies on the line segment between the points p1 and p2 and that is at a distance from the first point determined by the ratio r1/(r1 + r2).