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# Ogre::Math Class Reference

Class to provide access to common mathematical functions. More...

`#include <OgreMath.h>`

List of all members.

## Public Types
enum | AngleUnit { AU_DEGREE, AU_RADIAN }
| The angular units used by the API. More...
## Public Member Functions
| Math (unsigned int trigTableSize=4096)
| Default constructor.
| ~Math ()
| Default destructor.
## Static Public Member Functions
static int | IAbs (int iValue)
static int | ICeil (float fValue)
static int | IFloor (float fValue)
static int | ISign (int iValue)
static Real | Abs (Real fValue)
static Degree | Abs (const Degree &dValue)
static Radian | Abs (const Radian &rValue)
static Radian | ACos (Real fValue)
static Radian | ASin (Real fValue)
static Radian | ATan (Real fValue)
static Radian | ATan2 (Real fY, Real fX)
static Real | Ceil (Real fValue)
static Real | Cos (const Radian &fValue, bool useTables=false)
| Cosine function.
static Real | Cos (Real fValue, bool useTables=false)
| Cosine function.
static Real | Exp (Real fValue)
static Real | Floor (Real fValue)
static Real | Log (Real fValue)
static Real | Pow (Real fBase, Real fExponent)
static Real | Sign (Real fValue)
static Radian | Sign (const Radian &rValue)
static Degree | Sign (const Degree &dValue)
static Real | Sin (const Radian &fValue, bool useTables=false)
| Sine function.
static Real | Sin (Real fValue, bool useTables=false)
| Sine function.
static Real | Sqr (Real fValue)
static Real | Sqrt (Real fValue)
static Radian | Sqrt (const Radian &fValue)
static Degree | Sqrt (const Degree &fValue)
static Real | InvSqrt (Real fValue)
| Inverse square root i.e.
static Real | UnitRandom ()
static Real | RangeRandom (Real fLow, Real fHigh)
static Real | SymmetricRandom ()
static Real | Tan (const Radian &fValue, bool useTables=false)
| Tangent function.
static Real | Tan (Real fValue, bool useTables=false)
| Tangent function.
static Real | DegreesToRadians (Real degrees)
static Real | RadiansToDegrees (Real radians)
static void | setAngleUnit (AngleUnit unit)
| These functions used to set the assumed angle units (radians or degrees) expected when using the Angle type.
static AngleUnit | getAngleUnit (void)
| Get the unit being used for angles.
static Real | AngleUnitsToRadians (Real units)
| Convert from the current AngleUnit to radians.
static Real | RadiansToAngleUnits (Real radians)
| Convert from radians to the current AngleUnit .
static Real | AngleUnitsToDegrees (Real units)
| Convert from the current AngleUnit to degrees.
static Real | DegreesToAngleUnits (Real degrees)
| Convert from degrees to the current AngleUnit.
static bool | pointInTri2D (const Vector2 &p, const Vector2 &a, const Vector2 &b, const Vector2 &c)
| Checks whether a given point is inside a triangle, in a 2-dimensional (Cartesian) space.
static bool | pointInTri3D (const Vector3 &p, const Vector3 &a, const Vector3 &b, const Vector3 &c, const Vector3 &normal)
| Checks whether a given 3D point is inside a triangle.
static std::pair< bool, Real > | intersects (const Ray &ray, const Plane &plane)
| Ray / plane intersection, returns boolean result and distance.
static std::pair< bool, Real > | intersects (const Ray &ray, const Sphere &sphere, bool discardInside=true)
| Ray / sphere intersection, returns boolean result and distance.
static std::pair< bool, Real > | intersects (const Ray &ray, const AxisAlignedBox &box)
| Ray / box intersection, returns boolean result and distance.
static bool | intersects (const Ray &ray, const AxisAlignedBox &box, Real *d1, Real *d2)
| Ray / box intersection, returns boolean result and two intersection distance.
static std::pair< bool, Real > | intersects (const Ray &ray, const Vector3 &a, const Vector3 &b, const Vector3 &c, const Vector3 &normal, bool positiveSide=true, bool negativeSide=true)
| Ray / triangle intersection, returns boolean result and distance.
static std::pair< bool, Real > | intersects (const Ray &ray, const Vector3 &a, const Vector3 &b, const Vector3 &c, bool positiveSide=true, bool negativeSide=true)
| Ray / triangle intersection, returns boolean result and distance.
static bool | intersects (const Sphere &sphere, const AxisAlignedBox &box)
| Sphere / box intersection test.
static bool | intersects (const Plane &plane, const AxisAlignedBox &box)
| Plane / box intersection test.
static std::pair< bool, Real > | intersects (const Ray &ray, const std::vector< Plane > &planeList, bool normalIsOutside)
| Ray / convex plane list intersection test.
static std::pair< bool, Real > | intersects (const Ray &ray, const std::list< Plane > &planeList, bool normalIsOutside)
| Ray / convex plane list intersection test.
static bool | intersects (const Sphere &sphere, const Plane &plane)
| Sphere / plane intersection test.
static bool | RealEqual (Real a, Real b, Real tolerance=std::numeric_limits< Real >::epsilon())
| Compare 2 reals, using tolerance for inaccuracies.
static Vector3 | calculateTangentSpaceVector (const Vector3 &position1, const Vector3 &position2, const Vector3 &position3, Real u1, Real v1, Real u2, Real v2, Real u3, Real v3)
| Calculates the tangent space vector for a given set of positions / texture coords.
static Matrix4 | buildReflectionMatrix (const Plane &p)
| Build a reflection matrix for the passed in plane.
static Vector4 | calculateFaceNormal (const Vector3 &v1, const Vector3 &v2, const Vector3 &v3)
| Calculate a face normal, including the w component which is the offset from the origin.
static Vector3 | calculateBasicFaceNormal (const Vector3 &v1, const Vector3 &v2, const Vector3 &v3)
| Calculate a face normal, no w-information.
static Vector4 | calculateFaceNormalWithoutNormalize (const Vector3 &v1, const Vector3 &v2, const Vector3 &v3)
| Calculate a face normal without normalize, including the w component which is the offset from the origin.
static Vector3 | calculateBasicFaceNormalWithoutNormalize (const Vector3 &v1, const Vector3 &v2, const Vector3 &v3)
| Calculate a face normal without normalize, no w-information.
static Real | gaussianDistribution (Real x, Real offset=0.0f, Real scale=1.0f)
| Generates a value based on the gaussian (normal) distribution function with the given offset and scale parameters.
## Static Public Attributes
static const Real | POS_INFINITY
static const Real | NEG_INFINITY
static const Real | PI
static const Real | TWO_PI
static const Real | HALF_PI
static const Real | fDeg2Rad
static const Real | fRad2Deg
## Protected Member Functions
void | buildTrigTables ()
| Private function to build trig tables.
## Static Protected Member Functions
static Real | SinTable (Real fValue)
static Real | TanTable (Real fValue)
## Static Protected Attributes
static AngleUnit | msAngleUnit
static int | mTrigTableSize
| Size of the trig tables as determined by constructor.
static Real | mTrigTableFactor
| Radian -> index factor value ( mTrigTableSize / 2 * PI ).
static Real * | mSinTable
static Real * | mTanTable

## Detailed Description

Class to provide access to common mathematical functions.

Remarks:
  Most of the maths functions are aliased versions of the C runtime library functions. They are aliased here to provide future optimisation opportunities, either from faster RTLs or custom math approximations.

Note:
  This is based on MgcMath.h from Wild Magic.

Definition at line 171 of file OgreMath.h.

## Member Enumeration Documentation

enum Ogre::Math::AngleUnit

  | The angular units used by the API. This functionality is now deprecated in favor of discreet angular unit types ( see Degree and Radian above ). The only place this functionality is actually still used is when parsing files. Search for usage of the Angle class for those instances Enumeration values:
  AU_DEGREE |
  AU_RADIAN |
Definition at line 179 of file OgreMath.h.

## Constructor & Destructor Documentation

Ogre::Math::Math | ( | unsigned int | trigTableSize = `4096` | ) |

  | Default constructor. Parameters:
  | trigTableSize | Optional parameter to set the size of the tables used to implement Sin, Cos, Tan

Ogre::Math::~Math | ( |  | ) |

| Default destructor.

## Member Function Documentation

static Radian Ogre::Math::Abs | ( | const Radian & | rValue | ) | `[static]`

| Definition at line 222 of file OgreMath.h.

static Degree Ogre::Math::Abs | ( | const Degree & | dValue | ) | `[static]`

| Definition at line 221 of file OgreMath.h.

static Real Ogre::Math::Abs | ( | Real | fValue | ) | `[static]`

| Definition at line 220 of file OgreMath.h.

static Radian Ogre::Math::ACos | ( | Real | fValue | ) | `[static]`

static Real Ogre::Math::AngleUnitsToDegrees | ( | Real | units | ) | `[static]`

| Convert from the current AngleUnit to degrees.

static Real Ogre::Math::AngleUnitsToRadians | ( | Real | units | ) | `[static]`

| Convert from the current AngleUnit to radians.

static Radian Ogre::Math::ASin | ( | Real | fValue | ) | `[static]`

static Radian Ogre::Math::ATan | ( | Real | fValue | ) | `[static]`

| Definition at line 225 of file OgreMath.h.

static Radian Ogre::Math::ATan2 | ( | Real | fY,
|  | Real | fX
| ) | `[static]`

| Definition at line 226 of file OgreMath.h.

static Matrix4 Ogre::Math::buildReflectionMatrix | ( | const Plane & | p | ) | `[static]`

| Build a reflection matrix for the passed in plane.

void Ogre::Math::buildTrigTables | ( |  | ) | `[protected]`

| Private function to build trig tables.

static Vector3 Ogre::Math::calculateBasicFaceNormal | ( | const Vector3 & | v1,
|  | const Vector3 & | v2,
|  | const Vector3 & | v3
| ) | `[static]`

| Calculate a face normal, no w-information.

static Vector3 Ogre::Math::calculateBasicFaceNormalWithoutNormalize | ( | const Vector3 & | v1,
|  | const Vector3 & | v2,
|  | const Vector3 & | v3
| ) | `[static]`

| Calculate a face normal without normalize, no w-information.

static Vector4 Ogre::Math::calculateFaceNormal | ( | const Vector3 & | v1,
|  | const Vector3 & | v2,
|  | const Vector3 & | v3
| ) | `[static]`

| Calculate a face normal, including the w component which is the offset from the origin.

static Vector4 Ogre::Math::calculateFaceNormalWithoutNormalize | ( | const Vector3 & | v1,
|  | const Vector3 & | v2,
|  | const Vector3 & | v3
| ) | `[static]`

| Calculate a face normal without normalize, including the w component which is the offset from the origin.

static Vector3 Ogre::Math::calculateTangentSpaceVector | ( | const Vector3 & | position1,
|  | const Vector3 & | position2,
|  | const Vector3 & | position3,
|  | Real | u1,
|  | Real | v1,
|  | Real | u2,
|  | Real | v2,
|  | Real | u3,
|  | Real | v3
| ) | `[static]`

| Calculates the tangent space vector for a given set of positions / texture coords.

static Real Ogre::Math::Ceil | ( | Real | fValue | ) | `[static]`

| Definition at line 227 of file OgreMath.h.

static Real Ogre::Math::Cos | ( | Real | fValue,
|  | bool | useTables = `false`
| ) | `[static]`

  | Cosine function. Parameters:
  | fValue | Angle in radians
  | useTables | If true, uses lookup tables rather than calculation - faster but less accurate.
Definition at line 246 of file OgreMath.h.

static Real Ogre::Math::Cos | ( | const Radian & | fValue,
|  | bool | useTables = `false`
| ) | `[static]`

  | Cosine function. Parameters:
  | fValue | Angle in radians
  | useTables | If true, uses lookup tables rather than calculation - faster but less accurate.
Definition at line 236 of file OgreMath.h.

static Real Ogre::Math::DegreesToAngleUnits | ( | Real | degrees | ) | `[static]`

| Convert from degrees to the current AngleUnit.

static Real Ogre::Math::DegreesToRadians | ( | Real | degrees | ) | `[static]`

| Definition at line 329 of file OgreMath.h.

static Real Ogre::Math::Exp | ( | Real | fValue | ) | `[static]`

| Definition at line 250 of file OgreMath.h.

static Real Ogre::Math::Floor | ( | Real | fValue | ) | `[static]`

| Definition at line 252 of file OgreMath.h.

static Real Ogre::Math::gaussianDistribution | ( | Real | x,
|  | Real | offset = `0.0f`,
|  | Real | scale = `1.0f`
| ) | `[static]`

| Generates a value based on the gaussian (normal) distribution function with the given offset and scale parameters.

static AngleUnit Ogre::Math::getAngleUnit | ( | void |  | ) | `[static]`

| Get the unit being used for angles.

static int Ogre::Math::IAbs | ( | int | iValue | ) | `[static]`

| Definition at line 215 of file OgreMath.h.

static int Ogre::Math::ICeil | ( | float | fValue | ) | `[static]`

| Definition at line 216 of file OgreMath.h.

static int Ogre::Math::IFloor | ( | float | fValue | ) | `[static]`

| Definition at line 217 of file OgreMath.h.

static bool Ogre::Math::intersects | ( | const Sphere & | sphere,
|  | const Plane & | plane
| ) | `[static]`

| Sphere / plane intersection test. Remarks: NB just do a plane.getDistance(sphere.getCenter()) for more detail!

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const std::list< Plane > & | planeList,
|  | bool | normalIsOutside
| ) | `[static]`

  | Ray / convex plane list intersection test. Parameters:
  | ray | The ray to test with
  | plaeList | List of planes which form a convex volume
  | normalIsOutside | Does the normal point outside the volume

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const std::vector< Plane > & | planeList,
|  | bool | normalIsOutside
| ) | `[static]`

  | Ray / convex plane list intersection test. Parameters:
  | ray | The ray to test with
  | plaeList | List of planes which form a convex volume
  | normalIsOutside | Does the normal point outside the volume

static bool Ogre::Math::intersects | ( | const Plane & | plane,
|  | const AxisAlignedBox & | box
| ) | `[static]`

| Plane / box intersection test.

static bool Ogre::Math::intersects | ( | const Sphere & | sphere,
|  | const AxisAlignedBox & | box
| ) | `[static]`

| Sphere / box intersection test.

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const Vector3 & | a,
|  | const Vector3 & | b,
|  | const Vector3 & | c,
|  | bool | positiveSide = `true`,
|  | bool | negativeSide = `true`
| ) | `[static]`

  | Ray / triangle intersection, returns boolean result and distance. Parameters:
  | ray | The ray.
  | a | The triangle's first vertex.
  | b | The triangle's second vertex.
  | c | The triangle's third vertex.
  | positiveSide | Intersect with "positive side" of the triangle
  | negativeSide | Intersect with "negative side" of the triangle
Returns: If the ray is intersects the triangle, a pair of true and the distance between intersection point and ray origin returned. If the ray isn't intersects the triangle, a pair of false and 0 returned.

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const Vector3 & | a,
|  | const Vector3 & | b,
|  | const Vector3 & | c,
|  | const Vector3 & | normal,
|  | bool | positiveSide = `true`,
|  | bool | negativeSide = `true`
| ) | `[static]`

  | Ray / triangle intersection, returns boolean result and distance. Parameters:
  | ray | The ray.
  | a | The triangle's first vertex.
  | b | The triangle's second vertex.
  | c | The triangle's third vertex.
  | normal | The triangle plane's normal (passed in rather than calculated on demand since the callermay already have it), doesn't need normalised since we don't care.
  | positiveSide | Intersect with "positive side" of the triangle
  | negativeSide | Intersect with "negative side" of the triangle
Returns: If the ray is intersects the triangle, a pair of true and the distance between intersection point and ray origin returned. If the ray isn't intersects the triangle, a pair of false and 0 returned.

static bool Ogre::Math::intersects | ( | const Ray & | ray,
|  | const AxisAlignedBox & | box,
|  | Real * | d1,
|  | Real * | d2
| ) | `[static]`

  | Ray / box intersection, returns boolean result and two intersection distance. Parameters:
  | ray | The ray.
  | box | The box.
  | d1 | A real pointer to retrieve the near intersection distance from the ray origin, maybe null which means don't care about the near intersection distance.
  | d2 | A real pointer to retrieve the far intersection distance from the ray origin, maybe null which means don't care about the far intersection distance.
Returns: If the ray is intersects the box, true is returned, and the near intersection distance is return by d1, the far intersection distance is return by d2. Guarantee 0 <= d1 <= d2. If the ray isn't intersects the box, false is returned, and d1 and d2 is unmodified.

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const AxisAlignedBox & | box
| ) | `[static]`

| Ray / box intersection, returns boolean result and distance.

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const Sphere & | sphere,
|  | bool | discardInside = `true`
| ) | `[static]`

| Ray / sphere intersection, returns boolean result and distance.

static std::pair<bool, Real> Ogre::Math::intersects | ( | const Ray & | ray,
|  | const Plane & | plane
| ) | `[static]`

| Ray / plane intersection, returns boolean result and distance.

static Real Ogre::Math::InvSqrt | ( | Real | fValue | ) | `[static]`

| Inverse square root i.e. 1 / Sqrt(x), good for vector normalisation.

static int Ogre::Math::ISign | ( | int | iValue | ) | `[static]`

static Real Ogre::Math::Log | ( | Real | fValue | ) | `[static]`

| Definition at line 254 of file OgreMath.h.

static bool Ogre::Math::pointInTri2D | ( | const Vector2 & | p,
|  | const Vector2 & | a,
|  | const Vector2 & | b,
|  | const Vector2 & | c
| ) | `[static]`

  | Checks whether a given point is inside a triangle, in a 2-dimensional (Cartesian) space. Remarks: The vertices of the triangle must be given in either trigonometrical (anticlockwise) or inverse trigonometrical (clockwise) order. Parameters:
  | p | The point.
  | a | The triangle's first vertex.
  | b | The triangle's second vertex.
  | c | The triangle's third vertex.
Returns: If the point resides in the triangle, true is returned. If the point is outside the triangle, false is returned.

static bool Ogre::Math::pointInTri3D | ( | const Vector3 & | p,
|  | const Vector3 & | a,
|  | const Vector3 & | b,
|  | const Vector3 & | c,
|  | const Vector3 & | normal
| ) | `[static]`

  | Checks whether a given 3D point is inside a triangle. Remarks: The vertices of the triangle must be given in either trigonometrical (anticlockwise) or inverse trigonometrical (clockwise) order, and the point must be guaranteed to be in the same plane as the triangle Parameters:
  | p | The point.
  | a | The triangle's first vertex.
  | b | The triangle's second vertex.
  | c | The triangle's third vertex.
  | normal | The triangle plane's normal (passed in rather than calculated on demand since the callermay already have it)
Returns: If the point resides in the triangle, true is returned. If the point is outside the triangle, false is returned.

static Real Ogre::Math::Pow | ( | Real | fBase,
|  | Real | fExponent
| ) | `[static]`

| Definition at line 256 of file OgreMath.h.

static Real Ogre::Math::RadiansToAngleUnits | ( | Real | radians | ) | `[static]`

| Convert from radians to the current AngleUnit .

static Real Ogre::Math::RadiansToDegrees | ( | Real | radians | ) | `[static]`

| Definition at line 330 of file OgreMath.h.

static Real Ogre::Math::RangeRandom | ( | Real | fLow,
|  | Real | fHigh
| ) | `[static]`

static bool Ogre::Math::RealEqual | ( | Real | a,
|  | Real | b,
|  | Real | tolerance = `std::numeric_limits< Real >::epsilon()`
| ) | `[static]`

| Compare 2 reals, using tolerance for inaccuracies.

static void Ogre::Math::setAngleUnit | ( | AngleUnit | unit | ) | `[static]`

| These functions used to set the assumed angle units (radians or degrees) expected when using the Angle type. You can set this directly after creating a new Root, and also before/after resource creation, depending on whether you want the change to affect resource files.

static Degree Ogre::Math::Sign | ( | const Degree & | dValue | ) | `[static]`

| Definition at line 263 of file OgreMath.h.

static Radian Ogre::Math::Sign | ( | const Radian & | rValue | ) | `[static]`

| Definition at line 259 of file OgreMath.h.

static Real Ogre::Math::Sign | ( | Real | fValue | ) | `[static]`

static Real Ogre::Math::Sin | ( | Real | fValue,
|  | bool | useTables = `false`
| ) | `[static]`

  | Sine function. Parameters:
  | fValue | Angle in radians
  | useTables | If true, uses lookup tables rather than calculation - faster but less accurate.
Definition at line 285 of file OgreMath.h.

static Real Ogre::Math::Sin | ( | const Radian & | fValue,
|  | bool | useTables = `false`
| ) | `[static]`

  | Sine function. Parameters:
  | fValue | Angle in radians
  | useTables | If true, uses lookup tables rather than calculation - faster but less accurate.
Definition at line 275 of file OgreMath.h.

static Real Ogre::Math::SinTable | ( | Real | fValue | ) | `[static, protected]`

static Real Ogre::Math::Sqr | ( | Real | fValue | ) | `[static]`

| Definition at line 289 of file OgreMath.h.

static Degree Ogre::Math::Sqrt | ( | const Degree & | fValue | ) | `[static]`

| Definition at line 295 of file OgreMath.h.

static Radian Ogre::Math::Sqrt | ( | const Radian & | fValue | ) | `[static]`

| Definition at line 293 of file OgreMath.h.

static Real Ogre::Math::Sqrt | ( | Real | fValue | ) | `[static]`

| Definition at line 291 of file OgreMath.h.

static Real Ogre::Math::SymmetricRandom | ( |  | ) | `[static]`

static Real Ogre::Math::Tan | ( | Real | fValue,
|  | bool | useTables = `false`
| ) | `[static]`

  | Tangent function. Parameters:
  | fValue | Angle in radians
  | useTables | If true, uses lookup tables rather than calculation - faster but less accurate.
Definition at line 325 of file OgreMath.h.

static Real Ogre::Math::Tan | ( | const Radian & | fValue,
|  | bool | useTables = `false`
| ) | `[static]`

  | Tangent function. Parameters:
  | fValue | Angle in radians
  | useTables | If true, uses lookup tables rather than calculation - faster but less accurate.
Definition at line 315 of file OgreMath.h.

static Real Ogre::Math::TanTable | ( | Real | fValue | ) | `[static, protected]`

static Real Ogre::Math::UnitRandom | ( |  | ) | `[static]`

## Member Data Documentation

const Real Ogre::Math::fDeg2Rad`[static]`

| Definition at line 547 of file OgreMath.h.

const Real Ogre::Math::fRad2Deg`[static]`

| Definition at line 548 of file OgreMath.h.

const Real Ogre::Math::HALF_PI`[static]`

| Definition at line 546 of file OgreMath.h.

AngleUnit Ogre::Math::msAngleUnit`[static, protected]`

| Definition at line 187 of file OgreMath.h.

Real* Ogre::Math::mSinTable`[static, protected]`

| Definition at line 194 of file OgreMath.h.

Real* Ogre::Math::mTanTable`[static, protected]`

| Definition at line 195 of file OgreMath.h.

Real Ogre::Math::mTrigTableFactor`[static, protected]`

| Radian -> index factor value ( mTrigTableSize / 2 * PI ). Definition at line 193 of file OgreMath.h.

int Ogre::Math::mTrigTableSize`[static, protected]`

| Size of the trig tables as determined by constructor. Definition at line 190 of file OgreMath.h.

const Real Ogre::Math::NEG_INFINITY`[static]`

| Definition at line 543 of file OgreMath.h.

const Real Ogre::Math::PI`[static]`

| Definition at line 544 of file OgreMath.h.

const Real Ogre::Math::POS_INFINITY`[static]`

| Definition at line 542 of file OgreMath.h.

const Real Ogre::Math::TWO_PI`[static]`

| Definition at line 545 of file OgreMath.h.

The documentation for this class was generated from the following file:

- OgreMath.h

Copyright © 2000-2005 by The OGRE Team
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sun Sep 30 10:51:42 2007