Quaternion class problem

I am starting a Quaternion class, and this is what I have so far:

Code:

---

class Vector3D;
class Matrix3X3;
class EulerAngle;

class Quaternion {
 public:
  float x, y, z, w;

  Quaternion(float a, float b, float c, float d) : x(a), y(b), z(c), w(d) {}
/*
  Quaternion(float d, const Vector3D &v) : x(v.x), y(v.y), z(v.z), w(d) {}
*/
  Quaternion(const Quaternion &q) : x(q.x), y(q.y), z(q.z), w(q.w) {}

 ~Quaternion() {}
};

---

EVERY file is included. When you uncomment the second constructor, i get 3 errors (edited a bit):
1. x is not a member of Vector3D, as the type is not yet defined in the second contructor.
2. y is not a member of Vector3D, as the type is not yet defined in the second contructor.
3. z is not a member of Vector3D, as the type is not yet defined in the second contructor.

x, y, and z are all public. Any ideas on the problem? Thanks :D .

Instead of giving a forward declaration of the class Vector3D, define the class Vector3D before the definition of the class Quaternion..

They are in different files, and it isnt a problem in other files.

Limitations of forward declaration:
- You can only use it if the size of the forwarded declaration is not needed
- You can not access any elements of the forwarded type

Change class Vector3D; to #include "Vector3D.h" (if you know what I mean.)

gg

I HAVE included other files, and in other classes I do the same thing, with no problems.

Quote:

---

1. x is not a member of Vector3D, as the type is not yet defined in the second contructor.
2. y is not a member of Vector3D, as the type is not yet defined in the second contructor.
3. z is not a member of Vector3D, as the type is not yet defined in the second contructor.

---

Are you calling your compiler a liar? ;)

Vector3D isn't a template class is it?

Post or attach the header file that contains Quaternion class.

gg

This is the complete header, the only compilation problem is the one I was talking about:

Code:

---

#ifndef __QUATERNION_H_INCLUDED__
#define __QUATERNION_H_INCLUDED__
#include <cmath>
#include "matrix.h"
#include "vector.h"
#include "euler.h"
using namespace std;

class Vector3D;
class Matrix3X3;
class EulerAngle;

class Quaternion {
 public:
  float x, y, z, w;

  Quaternion(float a, float b, float c, float d) : x(a), y(b), z(c), w(d) {}

  Quaternion(float d, const Vector3D &v) : x(v.x), y(v.y), z(v.z), w(d) {}

  Quaternion(const Quaternion &q) : x(q.x), y(q.y), z(q.z), w(q.w) {}

  ~Quaternion() {}

  const Quaternion operator*(float m) const;
  const Quaternion operator/(float m) const;
  Quaternion &operator*=(float m);
  Quaternion &operator/=(float m);
  bool operator==(const Quaternion &q) const;
  bool operator!=(const Quaternion &q) const;

  float length() const;
  Quaternion normalize() const;
  Quaternion conjugate() const;
};

#endif

---

And no, none of my classes are templates.

Try removing the forward declarations. If that doesn't work, post vector.h

gg

I removed them, and got these errors:

It looks like it doesn't know what a Vector3D is. Is that declared in vector.h?

gg

Is what declared in vector.h? Vector3D? Yes, most definetly!

Vector.h:

Code:

---

#ifndef __VECTOR3D_H_INCLUDED__
#define __VECTOR3D_H_INCLUDED__
#include <cmath>
#include "matrix.h"
#include "euler.h"
#include "quaternion.h"
using namespace std;

class Matrix3X3;
class Quaternion;
class EulerAngle;

class Vector3D {
 public:
  float x, y, z;

/*Constructors / Deconstructors:
 Vector3D v: x, y, and z are all undefined.
 Vector3D v2(1, 2, 3): x, y, and z are set to 1, 2, and 3, respectivly.
 Vector3D v3(Vector3D v4): v3.x, v3.y, and v3.z are all set to v4.x, v4.y, and v4.z, respectivly.
 ~Vector3D(): Deconstructs the vector.
*/
  Vector3D() {}

  Vector3D(float a, float b, float c) : x(a), y(b), z(c) {}

  Vector3D(const Vector3D &v) : x(v.x), y(v.y), z(v.z) {}

  ~Vector3D() {}

/*Operator overloadings:
 Vector3D operator+(const Vector3D &v): x, y, and z are added to v.x, v.y, and v.z, respectivly.
 Vector3D operator-(const Vector3D &v): x, y, and z are subtracted from v.x, v.y, and v.z, respectivly.
 Vector3D operator*(float w): x, y, and z are all multiplied by w.
 Vector3D operator/(float w): x, y, and z are all divided by w.
 Vector3D operator-(): negate the vector - x, y, and z are set to -x, -y, and -z, respectivly
 Vector3D &operator+=(const Vector3D &v): x, y, and z are added to v.x, v.y, and v.z, respectivly, and vector is set with new values.
 Vector3D &operator-=(const Vector3D &v): x, y, and z are subtracted from v.x, v.y, and v.z, respectivly, and vector is set with new values.
 Vector3D &operator*=(float w): x, y, and z are all multiplied by w, and vector is set with new values.
 Vector3D &operator/=(float w): x, y, and z are all divided by w, and vector is set with new values.
 Vector3D &operator=(const Vector3D &v): this vector is set to v.
 bool operator==(const Vector3D &v): returns true if Vector3Ds' are equal, false otherwise.
 bool operator!=(const Vector3D &v): returns true if Vector3Ds' are not equal, false otherwise.
*/
  const Vector3D operator+(const Vector3D &v) const;
  const Vector3D operator-(const Vector3D &v) const;
  const Vector3D operator*(float w) const;
  const Vector3D operator/(float w) const;
  Vector3D operator-() const;
  Vector3D &operator+=(const Vector3D &v);
  Vector3D &operator-=(const Vector3D &v);
  Vector3D &operator*=(float w);
  Vector3D &operator/=(float w);
  Vector3D &operator=(const Vector3D &v);
  bool operator==(const Vector3D &v) const;
  bool operator!=(const Vector3D &v) const;

/*Other functions:
 float length(): returns the length of the vector.
 Vector3D normalize(): normalize the vector, vector / length of vector
 float dotProduct(const Vector3D &v): returns the dotProduct, x * v.x + y * v.y + z * v.z
 Vector3D crossProduct(const Vector3D &v): returns cross product between this vector and v.
 float distance(const Vector3D &v): returns distance between this vector and v.
 float angleBetween(const Vector3D &v): returns the angle (in radians) between the 2 vectors.
*/
  float length() const;
  Vector3D normalize() const;
  float dotProduct(const Vector3D &v) const;
  Vector3D crossProduct(const Vector3D &v) const;
  float distance(const Vector3D &v) const;
  float angleBetween(const Vector3D &v) const;
};

#endif

---

This is euler.h, and it compiles without error:

Code:

---

#ifndef __EULER_H_INCLUDED__
#define __EULER_H_INCLUDED__
#include <cmath>
#include "matrix.h"
#include "vector.h"
#include "quaternion.h"
using namespace std;

class Vector3D;
class Matrix3X3;
class Quaternion;

class EulerAngle {
 public:
  float h, p, b;

/*Constructors / Deconstructors:
 EulerAngle e: all variables are undefined.
 EulerAngle e2(1, 2, 3): heading is set to 1, pitch is set to 2, bank is set to 3.
 EulerAngle e3(Vector3D v): h is set to v.x, p is set to v.y, and b is set to v.z.
 EulerAngle e4(EulerAngle e): h, p, and b are set to e.h, e.p, and e.b, respectivly.
*/
  EulerAngle(float a, float b, float c) : h(a), p(b), b(c) {}

  EulerAngle(const Vector3D &v) : h(v.x), p(v.y), b(v.z) {}

  EulerAngle(const EulerAngle &ea) : h(ea.h), p(ea.p), b(ea.b) {}

  ~EulerAngle() {}
};

#endif

---

Ahh, ok.

Only #inlude what you need. If you don't use Quaternion class, then don't include it.

The problem is circular inclusion is preventing the compiler from knowing about Vector3D. Here is an example:

Code:

---

#ifndef _A_H_
#define _A_H_

#include "B.h"

struct A
{
    int n;
};

#endif

---

Code:

---

#ifndef _B_H_
#define _B_H_

#include "A.h"

struct B
{
    int n;

    B(A a) : n(a.n) {}
};

#endif

---

Code:

---

#include "A.h"
#include "B.h"

int main()
{
    A a;
    a.n = 3;

    B b(a);

        return 0;
}//main

---

B.h(10) : error C2629: unexpected 'struct B ('
B.h(10) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body
main.cpp(11) : error C2440: 'initializing' : cannot convert from 'struct A' to 'struct B' - No constructor could take the source type, or constructor overload resolution was ambiguous

My errors are a little different but it's the same problem.
Since A doesn't need to know anything about B, A.h shouldn't include B.h

Go through your headers and clean em up.

gg

Ahhhhhh, yay :D :D :D. Thanks, I'm EXTREMELY grateful :D :D .