/*
Matrix.h
Written by Matthew Fisher

a 4x4 matrix structure.  Used very often for affine vector transformations.
*/

class Matrix
{
public:
	//Initalization
	Matrix();
	Matrix(const Matrix &M);

#ifdef USE_DIRECTX
	Matrix(const D3DXMATRIX &M);	//initalizes the matrix with a D3DXMATRIX
#endif

	//Assignment
	Matrix& operator = (const Matrix &M);
	
	//Basic Transforms
	void Identity();
	void Scaling(const Vec3 &ScaleFactors);
	void Scaling(float Scale)
	{
		Scaling(Vec3(Scale, Scale, Scale));
	}
	void Translation(const Vec3 &Pos);

	//Rotation Transforms
	void Rotation(const Vec3 &Axis, float Angle, const Vec3 &Center);
	void Rotation(const Vec3 &Axis, float Angle);
	void Rotation(float Yaw, float Pitch, float Roll);
	void RotationX(float Theta);
	void RotationY(float Theta);
	void RotationZ(float Theta);

	//Complex or Composite Transforms
	void LookAt(const Vec3 &Eye, const Vec3 &At, const Vec3 &Up);
	void Orthogonal(float Width, float Height, float ZNear, float ZFar);
	void Perspective(float Width, float Height, float ZNear, float ZFar);
	void PerspectiveFov(float FOV, float Aspect, float ZNear, float ZFar);
	void Face(const Vec3 &v1, const Vec3 &v2);		//Constructs a matrix that will make all the vector facing v1 now face towards v2.
	void Viewport(float Width, float Height);

	void SetProduct(const Matrix &Left, const Matrix &Right);	//loads this matrix as the product of the given matrices
	void Invert();			//Inverts the current matrix
	void Transpose();		//Transposes the current matrix
	float Determinant();	//returns the determinant of this matrix

#ifdef USE_DIRECTX
	operator D3DXMATRIX();	//converts this matrix into a D3DXMATRIX
#endif
	
	inline float* operator [] (int Row);				//returns the 4 elements in the requested Row
	inline const float* operator [] (int Row) const;	//returns the 4 elements in the requested Row

	float Data[4][4];	//the data itself
};

ostream& operator << (ostream &os, const Matrix &m);		//Outputs the 16 elements in the matrix
istream& operator >> (istream &os, Matrix &m);				//Inputs the 16 elements in the matrix

Matrix operator * (const Matrix &Left, const Matrix &Right);
Matrix operator * (const Matrix &Left, float &Right);
Matrix operator * (float &Left, const Matrix &Right);			//Matrix-Matrix and Matrix-float multiplication
Matrix operator + (const Matrix &Left, const Matrix &Right);
Matrix operator - (const Matrix &Left, const Matrix &Right);	//Matrix-Matrix addition/mulitplication

Vec4 operator * (const Vec4 &Left, const Matrix &Right);		//4-vector Matrix multiplication

//transforms the vector Left, extended to (x, y, z, 1), by the matrix Right, storing the result in Target
void Vec3TransformCoord(Vec3 &Target, const Vec3 &Left, const Matrix &Right);

//transforms the vector Left, extended to (x, y, z, 0), by the matrix Right, storing the result in Target
void Vec3TransformNormal(Vec3 &Target, const Vec3 &Left, const Matrix &Right);

//transforms the vector Left, extended to (x, y, z, 1), by the matrix Right, projecting the result
//back into w = 1, and storing the result in Target
void Vec3TransformProjectCoord(Vec3 &Target, const Vec3 &Left, const Matrix &Right);

//Matrix inline functions
#ifndef __MATRIX_INLINE
#define __MATRIX_INLINE
inline float* Matrix::operator [] (int Row)
{
	return Data[Row];
}

inline const float* Matrix::operator [] (int Row) const
{
	return Data[Row];
}
#endif