geom.h File Reference

Physical geometry objects. More...

Go to the source code of this file.

Classes
struct	vec2
	two dimensional Cartesian vector object More...
struct	vec
	three dimensional Cartesian vector object More...
struct	std::hash< vec >
struct	bvec
	three dimensional Cartesian byte vector More...
struct	vec4< T >
	A four dimensional Cartesian-space vector template. More...
class	matrix3
	matrix3: 3x3 matrix comprised of three vec3 vectors arranged as follows: [ a1 b1 c1 a2 b2 c2 a3 b3 c3 ] More...
struct	matrix4x3
	floating point 4x3 matrix object defined as four column vectors, a-d takes the form as follows: [ a1 b1 c1 d1 (x) a2 b2 c2 d2 (y) a3 b3 c3 d3 ] (z) More...
struct	ivec
struct	std::hash< ivec >
struct	ivec2
	integer vector2 More...
struct	svec
	short integer three-vector object More...
struct	matrix4
	floating point 4x4 array object More...
struct	GenericVec2< T >
struct	GenericVec3< T >

Functions
bool	raysphereintersect (const vec &center, float radius, const vec &o, const vec &ray, float &dist)
bool	rayboxintersect (const vec &b, const vec &s, const vec &o, const vec &ray, float &dist, int &orient)
bool	linecylinderintersect (const vec &from, const vec &to, const vec &start, const vec &end, float radius, float &dist)
	Determines whether a line segment intersects a specified cylinder.
int	polyclip (const vec *in, int numin, const vec &dir, float below, float above, vec *out)
int	mod360 (int angle)
	Returns the angle passed to it, clamped to 0...360.
const vec2 &	sincosmod360 (int angle)
	Returns a vec2 containing (cos, sine) for a given integral angle.
float	cos360 (int angle)
	Returns the cosine for an angle (in degrees)
float	sin360 (int angle)
	Returns the sine for an angle (in degrees)
float	tan360 (int angle)
	Returns the tangent for an angle (in degrees)
float	cotan360 (int angle)
	Returns the cotangent for an angle (in degrees)

Variables
const int	R [3] = {1, 2, 0}
const int	C [3] = {2, 0, 1}
const int	D [3] = {0, 1, 2}
const vec2	sincos360 []

Detailed Description

Physical geometry objects.

This file describes objects which represent concrete geometric constructions, such as vectors that represent 2D, 3D, and 4D Cartesian coordinates, as well as more complex geometric structures such as quaternions and matrices.

Function Documentation

cos360()

float cos360 ( int angle )

inline

Returns the cosine for an angle (in degrees)

Must be within the bounds of 0...720. Uses a lookup table for integral values in degrees.

Parameters

angle

the angle to get the cosine of (in degrees)

Returns

the cosine of that angle

cotan360()

float cotan360 ( int angle )

inline

Returns the cotangent for an angle (in degrees)

Must be within the bounds of 0...720. Uses a lookup table for integral values in degrees.

Parameters

angle

the angle to get the cotangent of (in degrees)

Returns

the cotangent of that angle

linecylinderintersect()

bool linecylinderintersect ( const vec & from, const vec & to, const vec & start, const vec & end, float radius, float & dist )

extern

Determines whether a line segment intersects a specified cylinder.

Calculates whether a specified line segment intersects a cylinder, defined by a line segment and a radius around it. Segments which intersect along an edge, face, or tangent to the curved surface are considered to be intersecting. A successful intersection will cause the function to return true.

Negative radii are handled the same as a positive radius of the same magnitude.

If the line segment is entirely within the boundaries of the cylinder, the segment is considered to be intersecting, with the intersection starting at the from location.

The distance along the line at which the segment intersects the cylinder is expressed as a value from 0 to 1 and returned through the reference parameter dist. If the segment is entirely within the cylinder, the segment's intersection distance is considered to be zero.

If no intersection with the cylinder is found, the dist value will be returned unchanged, and the function will return false.

Parameters

from	the start point of the intersecting line segment
to	the end point of the intersecting line segment
start	the start point of the cylinder's axial line segment
end	the endpoint of the cylinder's axial line segment
radius	the radius of the cylinder to be intersected
dist	the value to set to the distance along the segment where intersection occured

Returns

true if the cylinder was intersected by the line segment

false if the cylinder and line segment did not intersect

mod360()

int mod360 ( int angle )

inline

Returns the angle passed to it, clamped to 0...360.

Normalizes negative/large angles passed to it to the range [0,360).

Parameters

angle

the angle to parse

Returns

the angle clamped to 0...360

sin360()

float sin360 ( int angle )

inline

Returns the sine for an angle (in degrees)

Must be within the bounds of 0...720. Uses a lookup table for integral values in degrees.

Parameters

angle

the angle to get the sine of (in degrees)

Returns

the sine of that angle

sincosmod360()

const vec2 & sincosmod360 ( int angle )

inline

Returns a vec2 containing (cos, sine) for a given integral angle.

Parameters

angle

the angle to get the sine/cos value of

Returns

a vec2 containing the cosine and sine of the given angle

tan360()

float tan360 ( int angle )

inline

Returns the tangent for an angle (in degrees)

Must be within the bounds of 0...720. Uses a lookup table for integral values in degrees.

Parameters

angle

the angle to get the tangent of (in degrees)

Returns

the tangent of that angle

Variable Documentation

C

const int C[3] = {2, 0, 1}

col

D

const int D[3] = {0, 1, 2}

depth

R

const int R[3] = {1, 2, 0}

row

sincos360

const vec2 sincos360[]

extern

a 721 element table of cosines, sines given integral values