ARITH3(2)ARITH3(2)
NAME
add3, sub3, neg3, div3, mul3, eqpt3, closept3, dot3, cross3, len3, dist3, unit3, midpt3, lerp3, reflect3, nearseg3, pldist3, vdiv3, vrem3, pn2f3, ppp2f3, fff2p3, pdiv4, add4, sub4 – operations on 3-d points and planes
SYNOPSIS
#include <draw.h>
#include <geometry.h>
Point3 add3(Point3 a, Point3 b)
Point3 sub3(Point3 a, Point3 b)
Point3 neg3(Point3 a)
Point3 div3(Point3 a, double b)
Point3 mul3(Point3 a, double b)
int eqpt3(Point3 p, Point3 q)
int closept3(Point3 p, Point3 q, double eps)
double dot3(Point3 p, Point3 q)
Point3 cross3(Point3 p, Point3 q)
double len3(Point3 p)
double dist3(Point3 p, Point3 q)
Point3 unit3(Point3 p)
Point3 midpt3(Point3 p, Point3 q)
Point3 lerp3(Point3 p, Point3 q, double alpha)
Point3 reflect3(Point3 p, Point3 p0, Point3 p1)
Point3 nearseg3(Point3 p0, Point3 p1, Point3 testp)
double pldist3(Point3 p, Point3 p0, Point3 p1)
double vdiv3(Point3 a, Point3 b)
Point3 vrem3(Point3 a, Point3 b)
Point3 pn2f3(Point3 p, Point3 n)
Point3 ppp2f3(Point3 p0, Point3 p1, Point3 p2)
Point3 fff2p3(Point3 f0, Point3 f1, Point3 f2)
Point3 pdiv4(Point3 a)
Point3 add4(Point3 a, Point3 b)
Point3 sub4(Point3 a, Point3 b)
DESCRIPTION
These routines do arithmetic on points and planes in affine or projective 3-space.
Type
typedef struct Point3 Point3; struct Point3{ double x, y, z, w; };
Routines whose names end in
Description
Add the coordinates of two points.
Subtract coordinates of two points.
Negate the coordinates of a point.
Multiply coordinates by a scalar.
Divide coordinates by a scalar.
Test two points for exact equality.
Is the distance between two points smaller than
Dot product.
Cross product.
Distance to the origin.
Distance between two points.
A unit vector parallel to
The midpoint of line segment
Linear interpolation between
The reflection of point
The closest point to
The distance from
Vector divide the length of the component of
Vector remainder the component of
The following routines convert amongst various representations of points
and planes. Planes are represented identically to points, by duality;
a point
Description
Compute the plane passing through
Compute the plane passing through three points.
Compute the intersection point of three planes.
The names of the following routines end in
Perspective division. Divide
Add the coordinates of two points.
Subtract the coordinates of two points.