re-GTA/src/math/Matrix.h

#pragma once

class CMatrix
{
public:
	RwMatrix m_matrix;
	RwMatrix *m_attachment;
	bool m_hasRwMatrix;	// are we the owner?

	CMatrix(void){
		m_attachment = nil;
		m_hasRwMatrix = false;
	}
	CMatrix(CMatrix const &m){
		m_attachment = nil;
		m_hasRwMatrix = false;
		*this = m;
	}
	CMatrix(RwMatrix *matrix, bool attach){
		m_attachment = nil;
		Attach(matrix, attach);
	}
	~CMatrix(void){
		if(m_hasRwMatrix && m_attachment)
			RwMatrixDestroy(m_attachment);
	}
	void Attach(RwMatrix *matrix, bool attach){
		if(m_hasRwMatrix && m_attachment)
			RwMatrixDestroy(m_attachment);
		m_attachment = matrix;
		m_hasRwMatrix = attach;
		Update();
	}
	void AttachRW(RwMatrix *matrix, bool attach){
		if(m_hasRwMatrix && m_attachment)
			RwMatrixDestroy(m_attachment);
		m_attachment = matrix;
		m_hasRwMatrix = attach;
		UpdateRW();
	}
	void Detach(void){
		if(m_hasRwMatrix && m_attachment)
			RwMatrixDestroy(m_attachment);
		m_attachment = nil;
	}
	void Update(void){
		m_matrix = *m_attachment;
	}
	void UpdateRW(void){
		if(m_attachment){
			*m_attachment = m_matrix;
			RwMatrixUpdate(m_attachment);
		}
	}
	void operator=(CMatrix const &rhs){
		m_matrix = rhs.m_matrix;
		if(m_attachment)
			UpdateRW();
	}

	CVector *GetPosition(void){ return (CVector*)&m_matrix.pos; }
	CVector *GetRight(void) { return (CVector*)&m_matrix.right; }
	CVector *GetForward(void) { return (CVector*)&m_matrix.up; }
	CVector *GetUp(void) { return (CVector*)&m_matrix.at; }
	void SetScale(float s){
		m_matrix.right.x = s;
		m_matrix.right.y = 0.0f;
		m_matrix.right.z = 0.0f;

		m_matrix.up.x = 0.0f;
		m_matrix.up.y = s;
		m_matrix.up.z = 0.0f;

		m_matrix.at.x = 0.0f;
		m_matrix.at.y = 0.0f;
		m_matrix.at.z = s;

		m_matrix.pos.x = 0.0f;
		m_matrix.pos.y = 0.0f;
		m_matrix.pos.z = 0.0f;
	}
	void SetRotateXOnly(float angle){
		float c = cos(angle);
		float s = sin(angle);

		m_matrix.right.x = 1.0f;
		m_matrix.right.y = 0.0f;
		m_matrix.right.z = 0.0f;

		m_matrix.up.x = 0.0f;
		m_matrix.up.y = c;
		m_matrix.up.z = s;

		m_matrix.at.x = 0.0f;
		m_matrix.at.y = -s;
		m_matrix.at.z = c;
	}
	void SetRotateX(float angle){
		SetRotateXOnly(angle);
		m_matrix.pos.x = 0.0f;
		m_matrix.pos.y = 0.0f;
		m_matrix.pos.z = 0.0f;
	}
	void SetRotateYOnly(float angle){
		float c = cos(angle);
		float s = sin(angle);

		m_matrix.right.x = c;
		m_matrix.right.y = 0.0f;
		m_matrix.right.z = -s;

		m_matrix.up.x = 0.0f;
		m_matrix.up.y = 1.0f;
		m_matrix.up.z = 0.0f;

		m_matrix.at.x = s;
		m_matrix.at.y = 0.0f;
		m_matrix.at.z = c;
	}
	void SetRotateY(float angle){
		SetRotateYOnly(angle);
		m_matrix.pos.x = 0.0f;
		m_matrix.pos.y = 0.0f;
		m_matrix.pos.z = 0.0f;
	}
	void SetRotateZOnly(float angle){
		float c = cos(angle);
		float s = sin(angle);

		m_matrix.right.x = c;
		m_matrix.right.y = s;
		m_matrix.right.z = 0.0f;

		m_matrix.up.x = -s;
		m_matrix.up.y = c;
		m_matrix.up.z = 0.0f;

		m_matrix.at.x = 0.0f;
		m_matrix.at.y = 0.0f;
		m_matrix.at.z = 1.0f;
	}
	void SetRotateZ(float angle){
		SetRotateZOnly(angle);
		m_matrix.pos.x = 0.0f;
		m_matrix.pos.y = 0.0f;
		m_matrix.pos.z = 0.0f;
	}
	void Reorthogonalise(void){
		CVector &r = *GetRight();
		CVector &f = *GetForward();
		CVector &u = *GetUp();
		u = CrossProduct(r, f);
		u.Normalise();
		r = CrossProduct(f, u);
		r.Normalise();
		f = CrossProduct(u, r);
	}
};

inline CMatrix&
Invert(const CMatrix &src, CMatrix &dst)
{
	// GTA handles this as a raw 4x4 orthonormal matrix
	// and trashes the RW flags, let's not do that
	// actual copy of librw code:
	RwMatrix *d = &dst.m_matrix;
	const RwMatrix *s = &src.m_matrix;
	d->right.x = s->right.x;
	d->right.y = s->up.x;
	d->right.z = s->at.x;
	d->up.x = s->right.y;
	d->up.y = s->up.y;
	d->up.z = s->at.y;
	d->at.x = s->right.z;
	d->at.y = s->up.z;
	d->at.z = s->at.z;
	d->pos.x = -(s->pos.x*s->right.x +
	               s->pos.y*s->right.y +
	               s->pos.z*s->right.z);
	d->pos.y = -(s->pos.x*s->up.x +
	               s->pos.y*s->up.y +
	               s->pos.z*s->up.z);
	d->pos.z = -(s->pos.x*s->at.x +
	               s->pos.y*s->at.y +
	               s->pos.z*s->at.z);
	d->flags = rwMATRIXTYPEORTHONORMAL;
	return dst;
}

inline CMatrix
Invert(const CMatrix &matrix)
{
	CMatrix inv;
	return Invert(matrix, inv);
}

inline CVector
operator*(const CMatrix &mat, const CVector &vec)
{
	return CVector(
		mat.m_matrix.right.x * vec.x + mat.m_matrix.up.x * vec.y + mat.m_matrix.at.x * vec.z + mat.m_matrix.pos.x,
		mat.m_matrix.right.y * vec.x + mat.m_matrix.up.y * vec.y + mat.m_matrix.at.y * vec.z + mat.m_matrix.pos.y,
		mat.m_matrix.right.z * vec.x + mat.m_matrix.up.z * vec.y + mat.m_matrix.at.z * vec.z + mat.m_matrix.pos.z);
}

inline CMatrix
operator*(const CMatrix &m1, const CMatrix &m2)
{
	CMatrix out;
	RwMatrix *dst = &out.m_matrix;
	const RwMatrix *src1 = &m1.m_matrix;
	const RwMatrix *src2 = &m2.m_matrix;
	dst->right.x = src1->right.x*src2->right.x + src1->up.x*src2->right.y + src1->at.x*src2->right.z;
	dst->right.y = src1->right.y*src2->right.x + src1->up.y*src2->right.y + src1->at.y*src2->right.z;
	dst->right.z = src1->right.z*src2->right.x + src1->up.z*src2->right.y + src1->at.z*src2->right.z;
	dst->up.x    = src1->right.x*src2->up.x    + src1->up.x*src2->up.y    + src1->at.x*src2->up.z;
	dst->up.y    = src1->right.y*src2->up.x    + src1->up.y*src2->up.y    + src1->at.y*src2->up.z;
	dst->up.z    = src1->right.z*src2->up.x    + src1->up.z*src2->up.y    + src1->at.z*src2->up.z;
	dst->at.x    = src1->right.x*src2->at.x    + src1->up.x*src2->at.y    + src1->at.x*src2->at.z;
	dst->at.y    = src1->right.y*src2->at.x    + src1->up.y*src2->at.y    + src1->at.y*src2->at.z;
	dst->at.z    = src1->right.z*src2->at.x    + src1->up.z*src2->at.y    + src1->at.z*src2->at.z;
	dst->pos.x   = src1->right.x*src2->pos.x   + src1->up.x*src2->pos.y   + src1->at.x*src2->pos.z + src1->pos.x;
	dst->pos.y   = src1->right.y*src2->pos.x   + src1->up.y*src2->pos.y   + src1->at.y*src2->pos.z + src1->pos.y;
	dst->pos.z   = src1->right.z*src2->pos.x   + src1->up.z*src2->pos.y   + src1->at.z*src2->pos.z + src1->pos.z;
	return out;
}

inline CVector
MultiplyInverse(const CMatrix &mat, const CVector &vec)
{
	CVector v(vec.x - mat.m_matrix.pos.x, vec.y - mat.m_matrix.pos.y, vec.z - mat.m_matrix.pos.z);
	return CVector(
		mat.m_matrix.right.x * v.x + mat.m_matrix.right.y * v.y + mat.m_matrix.right.z * v.z,
		mat.m_matrix.up.x * v.x + mat.m_matrix.up.y * v.y + mat.m_matrix.up.z * v.z,
		mat.m_matrix.at.x * v.x + mat.m_matrix.at.y * v.y + mat.m_matrix.at.z * v.z);
}

inline CVector
Multiply3x3(const CMatrix &mat, const CVector &vec)
{
	return CVector(
		mat.m_matrix.right.x * vec.x + mat.m_matrix.up.x * vec.y + mat.m_matrix.at.x * vec.z,
		mat.m_matrix.right.y * vec.x + mat.m_matrix.up.y * vec.y + mat.m_matrix.at.y * vec.z,
		mat.m_matrix.right.z * vec.x + mat.m_matrix.up.z * vec.y + mat.m_matrix.at.z * vec.z);
}