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Define a class Mat4 as a vector of four Vec4s?

firix (438)
Hi friends,

Define a class Mat4 as a vector of four Vec4s. Define operator[] to return a Vec4 for Mat4 . Define the usual matrix operations for this type. Define a function doing Gaussian elimination for a Mat4.

An example is the book of Bjarne storustrup
I could not write more.

How I can do?


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class Vec4{
	vector<floatt> fval;
public:
	Vec4()
	{
		fval.push_back(floatt(rand() % 2 + 2.1f, rand() % 3 + 1.7f,rand() % 5 + 7.3f, rand() % 3 + 4.9f));
	}

	Vec4(floatt f)
	{
		fval.push_back(floatt(f));
	}
	Vec4(const Vec4 &f)
	{
		fval = f.fval;
	}

	Vec4 &operator=(const Vec4 &f)
	{
		fval =  f.fval;
		return *this;
	}


	void display()const
	{
		cout << "("<< fval[0].f[0] << ")" << "(" << fval[0].f[1] << ")" <<  "(" <<fval[0].f[2] << ")"<<"("<<fval[0].f[3]<< ")" << endl;

	}

	Vec4 &operator+(const Vec4 &v)
	{
		Vec4 &result = *this;
		result.fval[0].f[0] += v.fval[0].f[0];
		result.fval[0].f[1] += v.fval[0].f[1];
		result.fval[0].f[2] += v.fval[0].f[2];
		result.fval[0].f[3] += v.fval[0].f[3];
		
		return result;
	}

	Vec4 &operator-(const Vec4 &v)
	{
		Vec4 &result = *this;
		result.fval[0].f[0] -= v.fval[0].f[0];
		result.fval[0].f[1] -= v.fval[0].f[1];
		result.fval[0].f[2] -= v.fval[0].f[2];
		result.fval[0].f[3] -= v.fval[0].f[3];
		
		return result;
	}

	Vec4 &operator/(const Vec4 &v)
	{
		Vec4 &result = *this;
		result.fval[0].f[0] /= v.fval[0].f[0];
		result.fval[0].f[1] /= v.fval[0].f[2];
		result.fval[0].f[2] /= v.fval[0].f[3];
		result.fval[0].f[3] /= v.fval[0].f[4];
		
		return result;
	}

	Vec4 &operator*(const Vec4 &v)
	{
		Vec4 &result = *this;
		result.fval[0].f[0] *= v.fval[0].f[0];
		result.fval[0].f[1] *= v.fval[0].f[1];
		result.fval[0].f[2] *= v.fval[0].f[2];
		result.fval[0].f[3] *= v.fval[0].f[3];
		
		return result;
	}

	
	Vec4 &operator+=(const Vec4 &v)
	{
		this->fval[0].f[0] += v.fval[0].f[0];
		this->fval[0].f[1] += v.fval[0].f[1];
		this->fval[0].f[2] += v.fval[0].f[2];
		this->fval[0].f[3] += v.fval[0].f[3];

		return *this;

	}
	Vec4 &operator-=(const Vec4 &v)
	{
		this->fval[0].f[0] -= v.fval[0].f[0];
		this->fval[0].f[1] -= v.fval[0].f[1];
		this->fval[0].f[2] -= v.fval[0].f[2];
		this->fval[0].f[3] -= v.fval[0].f[3];

		return *this;

	}
	Vec4 &operator*=(const Vec4 &v)
	{
		this->fval[0].f[0] *= v.fval[0].f[0];
		this->fval[0].f[1] *= v.fval[0].f[1];
		this->fval[0].f[2] *= v.fval[0].f[2];
		this->fval[0].f[3] *= v.fval[0].f[3];

		return *this;

	}
	Vec4 &operator/=(const Vec4 &v)
	{
		this->fval[0].f[0] /= v.fval[0].f[0];
		this->fval[0].f[1] /= v.fval[0].f[1];
		this->fval[0].f[2] /= v.fval[0].f[2];
		this->fval[0].f[3] /= v.fval[0].f[3];

		return *this;

	}


	float &operator [] (int index)	
	{ 	

		return  this->fval[0].f[index];
	
	}

	friend ostream &operator<<(ostream &os, Vec4 &v);
	friend istream &operator>>(istream &is, Vec4 &v);



};


ostream &operator<<(ostream &os, Vec4 &v)
{
	return  os << "(" << v.fval[0].f[0] << ")"  << "(" << v.fval[0].f[1] << "(" << v.fval[0].f[2] << ")" << "(" << v.fval[0].f[3] << ")" <<   endl;

}

istream &operator>>(istream &is, Vec4 &v)
{
	return is >>  v.fval[0].f[0] >> v.fval[0].f[1] >> v.fval[0].f[2] >> v.fval[0].f[3];
}


struct Veco{
	Vec4  v[4];
	Veco(Vec4 v1, Vec4 v2, Vec4 v3, Vec4 v4)
	{

		v[0] = v1;
		v[1] = v2;
		v[2] = v3;
		v[3] = v4;
	}

	Veco(const Veco &r)
	{
		v[0] = r.v[0];
		v[1] = r.v[1];
		v[2] = r.v[2];
		v[3] = r.v[3];
	}

	Veco operator=(const Veco &r)
	{	
		v[0] = r.v[0];
		v[1] = r.v[1];
		v[2] = r.v[2];
		v[3] = r.v[3];

		return *this;
	}
};


class Mat4{
	vector<Veco> mval;
public:
	Mat4()
	{
		mval.push_back(Veco(floatt(rand() % 3 + 4.9f, rand() % 3 + 1.9f,rand() % 5 + 7.8f, rand() % 9 + 1.9f),
		floatt(rand() % 4 + 3.8f, rand() % 2 + 2.8f,rand() % 1 + 6.1f, rand() % 5 + 4.9f),
		floatt(rand() % 7 + 2.7f, rand() % 9 + 3.2f,rand() % 3 + 3.4f, rand() % 2 + 4.54f),
		floatt(rand() % 9 + 1.6f, rand() % 8 + 4.1f,rand() % 9 + 1.7f, rand() % 7 + 1.2f)));

	}

	void display()const
	{
	 
		mval[0].v[0].display();
		mval[0].v[1].display();
		mval[0].v[2].display();
		mval[0].v[3].display();

	}

	Vec4 &operator[](int index)
	{
		return this->mval[0].v[index];
	}

};





Last edited on
jsmith (5804)
The declarations and implementations of most of your operators are wrong.

The correct declarations are:
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    Vec4 operator+( const Vec4& rhs ) const;
    Vec4 operator-( const Vec4& rhs ) const;
    Vec4 operator/( const Vec4& rhs ) const;
    Vec4 operator*( const Vec4& rhs ) const;


However, for doing Gaussian elimination, I don't understand why you need some of them --
namely the / and *. You want to divide and multiply by scalars, not by vectors.


firix (438)
What you do not understand?

everything is very clear:



Define a class Mat4 as a vector of four Vec4s. Define operator[] to return a Vec4 for Mat4 . Define the usual matrix operations for this type. Define a function doing Gaussian elimination for a Mat4.


Written by Bjarne Stroustrup, the creator of C++.
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