/
Vector4.h
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Vector4.h
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#pragma once
#include <sstream>
/* greebo: This file contains the templated class definition of the three-component vector
*
* BasicVector4: A vector with three components of type <Element>
*
* The BasicVector4 is equipped with the most important operators like *, *= and so on.
*
* Note: The most commonly used Vector4 is a BasicVector4<float>, this is also defined in this file
*
* Note: that the multiplication of a Vector4 with another one (Vector4*Vector4) does NOT
* result in an inner product but in a component-wise scaling. Use the .dot() method to
* execute an inner product of two vectors.
*/
#include "lrint.h"
#include "FloatTools.h"
#include "Vector3.h"
/// A 4-element vector of type <Element>
template<typename Element>
class BasicVector4
{
// The components of this vector
Element _v[4];
public:
// Public typedef to read the type of our elements
typedef Element ElementType;
// Constructor (no arguments)
BasicVector4() {
_v[0] = 0;
_v[1] = 0;
_v[2] = 0;
_v[3] = 0;
}
/**
* \brief Construct a BasicVector4 out of 4 explicit values.
*
* If the W coordinate is unspecified it will default to 1.
*/
BasicVector4(Element x_, Element y_, Element z_, Element w_ = 1)
{
_v[0] = x_;
_v[1] = y_;
_v[2] = z_;
_v[3] = w_;
}
// Construct a BasicVector4 out of a Vector3 plus a W value (default 1)
BasicVector4(const BasicVector3<Element>& other, Element w_ = 1)
{
_v[0] = other.x();
_v[1] = other.y();
_v[2] = other.z();
_v[3] = w_;
}
// Return non-constant references to the components
Element& x() { return _v[0]; }
Element& y() { return _v[1]; }
Element& z() { return _v[2]; }
Element& w() { return _v[3]; }
// Return constant references to the components
const Element& x() const { return _v[0]; }
const Element& y() const { return _v[1]; }
const Element& z() const { return _v[2]; }
const Element& w() const { return _v[3]; }
Element index(std::size_t i) const {
return _v[i];
}
Element& index(std::size_t i) {
return _v[i];
}
/**
* \brief
* Return a readable (pretty-printed) string representation of the vector
*
* We need a dedicated function for this because the standard operator<< is
* already used for serialisation to the less readable space-separated text
* format.
*/
std::string pp() const
{
std::stringstream ss;
ss << "(" << x() << ", " << y() << ", " << z() << ", " << w() << ")";
return ss.str();
}
/** Compare this BasicVector4 against another for equality.
*/
bool operator== (const BasicVector4& other) const {
return (other.x() == x()
&& other.y() == y()
&& other.z() == z()
&& other.w() == w());
}
/** Compare this BasicVector4 against another for inequality.
*/
bool operator!= (const BasicVector4& other) const {
return !(*this == other);
}
/* Define the addition operators + and += with any other BasicVector4 of type OtherElement
* The vectors are added to each other element-wise
*/
template<typename OtherElement>
BasicVector4<Element> operator+ (const BasicVector4<OtherElement>& other) const {
return BasicVector4<Element>(
_v[0] + static_cast<Element>(other.x()),
_v[1] + static_cast<Element>(other.y()),
_v[2] + static_cast<Element>(other.z()),
_v[3] + static_cast<Element>(other.w())
);
}
template<typename OtherElement>
BasicVector4<Element>& operator+= (const BasicVector4<OtherElement>& other) {
_v[0] += static_cast<Element>(other.x());
_v[1] += static_cast<Element>(other.y());
_v[2] += static_cast<Element>(other.z());
_v[3] += static_cast<Element>(other.w());
return *this;
}
/* Define the substraction operators - and -= with any other BasicVector4 of type OtherElement
* The vectors are substracted from each other element-wise
*/
template<typename OtherElement>
BasicVector4<Element> operator- (const BasicVector4<OtherElement>& other) const {
return BasicVector4<Element>(
_v[0] - static_cast<Element>(other.x()),
_v[1] - static_cast<Element>(other.y()),
_v[2] - static_cast<Element>(other.z()),
_v[3] - static_cast<Element>(other.w())
);
}
template<typename OtherElement>
BasicVector4<Element>& operator-= (const BasicVector4<OtherElement>& other) {
_v[0] -= static_cast<Element>(other.x());
_v[1] -= static_cast<Element>(other.y());
_v[2] -= static_cast<Element>(other.z());
_v[3] -= static_cast<Element>(other.w());
return *this;
}
/* Define the multiplication operators * and *= with another Vector4 of type OtherElement
*
* The vectors are multiplied element-wise
*
* greebo: This is mathematically kind of senseless, as this is a mixture of
* a dot product and scalar multiplication. It can be used to scale each
* vector component by a different factor, so maybe this comes in handy.
*/
template<typename OtherElement>
BasicVector4<Element> operator* (const BasicVector4<OtherElement>& other) const {
return BasicVector4<Element>(
_v[0] * static_cast<Element>(other.x()),
_v[1] * static_cast<Element>(other.y()),
_v[2] * static_cast<Element>(other.z()),
_v[3] * static_cast<Element>(other.w())
);
}
template<typename OtherElement>
BasicVector4<Element>& operator*= (const BasicVector4<OtherElement>& other) {
_v[0] *= static_cast<Element>(other.x());
_v[1] *= static_cast<Element>(other.y());
_v[2] *= static_cast<Element>(other.z());
_v[3] *= static_cast<Element>(other.w());
return *this;
}
/* Define the multiplications * and *= with a scalar
*/
template<typename OtherElement>
BasicVector4<Element>& operator*= (const OtherElement& other) {
Element factor = static_cast<Element>(other);
_v[0] *= factor;
_v[1] *= factor;
_v[2] *= factor;
_v[3] *= factor;
return *this;
}
/* Define the division operators / and /= with another Vector4 of type OtherElement
* The vectors are divided element-wise
*/
template<typename OtherElement>
BasicVector4<Element> operator/ (const BasicVector4<OtherElement>& other) const {
return BasicVector4<Element>(
_v[0] / static_cast<Element>(other.x()),
_v[1] / static_cast<Element>(other.y()),
_v[2] / static_cast<Element>(other.z()),
_v[3] / static_cast<Element>(other.w())
);
}
template<typename OtherElement>
BasicVector4<Element>& operator/= (const BasicVector4<OtherElement>& other) {
_v[0] /= static_cast<Element>(other.x());
_v[1] /= static_cast<Element>(other.y());
_v[2] /= static_cast<Element>(other.z());
_v[3] /= static_cast<Element>(other.w());
return *this;
}
/* Define the scalar divisions / and /=
*/
template<typename OtherElement>
BasicVector4<Element> operator/ (const OtherElement& other) const {
Element divisor = static_cast<Element>(other);
return BasicVector4<Element>(
_v[0] / divisor,
_v[1] / divisor,
_v[2] / divisor,
_v[3] / divisor
);
}
template<typename OtherElement>
BasicVector4<Element>& operator/= (const OtherElement& other) {
Element divisor = static_cast<Element>(other);
_v[0] /= divisor;
_v[1] /= divisor;
_v[2] /= divisor;
_v[3] /= divisor;
return *this;
}
/* Scalar product this vector with another Vector4,
* returning the projection of <self> onto <other>
*
* @param other
* The Vector4 to dot-product with this Vector4.
*
* @returns
* The inner product (a scalar): a[0]*b[0] + a[1]*b[1] + a[2]*b[2] + a[3]*b[3]
*/
template<typename OtherT>
Element dot(const BasicVector4<OtherT>& other) const {
return Element(_v[0] * other.x() +
_v[1] * other.y() +
_v[2] * other.z() +
_v[3] * other.w());
}
/** Project this homogeneous Vector4 into a Cartesian Vector3
* by dividing by w.
*
* @returns
* A Vector3 representing the Cartesian equivalent of this
* homogeneous vector.
*/
BasicVector3<Element> getProjected() {
return BasicVector3<Element>(
_v[0] / _v[3],
_v[1] / _v[3],
_v[2] / _v[3]);
}
/** Implicit cast to C-style array. This allows a Vector4 to be
* passed directly to GL functions that expect an array (e.g.
* glFloat4dv()). These functions implicitly provide operator[]
* as well, since the C-style array provides this function.
*/
operator const Element* () const {
return _v;
}
operator Element* () {
return _v;
}
/* Cast this Vector4 onto a Vector3, both const and non-const
*/
BasicVector3<Element>& getVector3() {
return *reinterpret_cast<BasicVector3<Element>*>(_v);
}
const BasicVector3<Element>& getVector3() const {
return *reinterpret_cast<const BasicVector3<Element>*>(_v);
}
/**
* Equality check with tolerance epsilon.
*/
template<typename OtherElement>
bool isEqual(const BasicVector4<OtherElement>& other, Element epsilon) const
{
return float_equal_epsilon(x(), other.x(), epsilon) &&
float_equal_epsilon(y(), other.y(), epsilon) &&
float_equal_epsilon(z(), other.z(), epsilon) &&
float_equal_epsilon(w(), other.w(), epsilon);
}
}; // BasicVector4
/// Multiply BasicVector4 with a scalar
template <
typename T, typename S,
typename = typename std::enable_if<std::is_arithmetic<S>::value, S>::type
>
BasicVector4<T> operator*(const BasicVector4<T>& v, S s)
{
return BasicVector4<T>(v.x() * s, v.y() * s, v.z() * s, v.w() * s);
}
/// Multiply BasicVector3 with a scalar
template <
typename T, typename S,
typename = typename std::enable_if<std::is_arithmetic<S>::value, S>::type
>
BasicVector4<T> operator*(S s, const BasicVector4<T>& v)
{
return v * s;
}
/// Stream insertion for BasicVector4
template<typename T>
inline std::ostream& operator<<(std::ostream& st, BasicVector4<T> vec)
{
return st << vec.x() << " " << vec.y() << " " << vec.z() << " " << vec.w();
}
/// Stream extraction for BasicVector4
template<typename T>
inline std::istream& operator>>(std::istream& st, BasicVector4<T>& vec)
{
return st >> std::skipws >> vec.x() >> vec.y() >> vec.z() >> vec.w();
}
// A 4-element vector stored in double-precision floating-point.
typedef BasicVector4<double> Vector4;
// A 4-element vector stored in single-precision floating-point.
typedef BasicVector4<float> Vector4f;