C++实现一个Vector3空间向量类

2019-04-14 15:31发布

站内文章 / 模拟电子
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Vector2,3,4类在DirectX中都有现成的可以调用，不过要实现其中的功能其实也不难，也都是一些简单的数学知识罢了。 本文用C++实现一个简单的Vector3类的功能，暂时有的功能是： 1 + - * /算术运算 2 向量的数量积，又叫：点乘 3 向量的向量积，又叫：叉乘 4 向量单位化（normalization) //Vecotr3.h #pragma once extern const double uZero; class Vector3 { float x, y, z; public: Vector3():x(0), y(0), z(0){} Vector3(float x1, float y1, float z1):x(x1), y(y1), z(z1){} Vector3(const Vector3 &v); ~Vector3(); void operator=(const Vector3 &v); Vector3 operator+(const Vector3 &v); Vector3 operator-(const Vector3 &v); Vector3 operator/(const Vector3 &v); Vector3 operator*(const Vector3 &v); Vector3 operator+(float f); Vector3 operator-(float f); Vector3 operator/(float f); Vector3 operator*(float f); float dot(const Vector3 &v); float length(); void normalize(); Vector3 crossProduct(const Vector3 &v); void printVec3(); }; //Vector3.cpp #include"Plane.h" #include const double uZero = 1e-6; //复制构造函数，必须为常量引用参数，否则编译不通过 Vector3::Vector3(const Vector3 &v):x(v.x), y(v.y), z(v.z) { } Vector3::~Vector3() { } void Vector3::operator=(const Vector3 &v) { x = v.x; y = v.y; z = v.z; } Vector3 Vector3::operator+(const Vector3 &v) { return Vector3(x+v.x, y+v.y, z+v.z); } Vector3 Vector3::operator-(const Vector3 &v) { return Vector3(x-v.x, y-v.y, z-v.z); } Vector3 Vector3::operator/(const Vector3 &v) { if (fabsf(v.x) <= uZero || fabsf(v.y) <= uZero || fabsf(v.z) <= uZero) { std::cerr<<"Over flow! "; return *this; } return Vector3(x/v.x, y/v.y, z/v.z); } Vector3 Vector3::operator*(const Vector3 &v) { return Vector3(x*v.x, y*v.y, z*v.z); } Vector3 Vector3::operator+(float f) { return Vector3(x+f, y+f, z+f); } Vector3 Vector3::operator-(float f) { return Vector3(x-f, y-f, z-f); } Vector3 Vector3::operator/(float f) { if (fabsf(f) < uZero) { std::cerr<<"Over flow! "; return *this; } return Vector3(x/f, y/f, z/f); } Vector3 Vector3::operator*(float f) { return Vector3(x*f, y*f, z*f); } float Vector3::dot(const Vector3 &v) { return x*v.x + y*v.y + z*v.z; } float Vector3::length() { return sqrtf(dot(*this)); } void Vector3::normalize() { float len = length(); if (len < uZero) len = 1; len = 1/len; x *= len; y *= len; z *= len; } /* Cross Product叉乘公式 aXb = | i, j, k | | a.x a.y a.z| | b.x b.y b.z| = (a.y*b.z -a.z*b.y)i + (a.z*b.x - a.x*b.z)j + (a.x*b.y - a.y*b.x)k */ Vector3 Vector3::crossProduct(const Vector3 &v) { return Vector3(y * v.z - z * v.y, z * v.x - x * v.z, x * v.y - y * v.x); } void Vector3::printVec3() { std::cout<<"("<
测试主程序： #include #include #include"Vector3.h" using namespace std; int main() { Vector3 v31; Vector3 v32(2.0f,3.0f,4.0f); Vector3 v33(v32 - 1.0f); cout<<"We have original Vector3s: "; v31.printVec3(); v32.printVec3(); v33.printVec3(); cout<<"v32 crossproduct v33 is: "; Vector3 v3233 = v32.crossProduct(v33); v3233.printVec3(); cout<<"Now we normalize them: "; v31.normalize(); v32.normalize(); v33.normalize(); v3233.normalize(); v31.printVec3(); v32.printVec3(); v33.printVec3(); v3233.printVec3(); system("pause"); return 0; }
运算结果：

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