#ifndef GFXMATH_VEC4_INCLUDED // -*- C++ -*-
#define GFXMATH_VEC4_INCLUDED

/************************************************************************

  4D Vector class.

  $Id: Vec4.h,v 1.10 1997/03/17 22:52:27 garland Exp $

 ************************************************************************/

namespace simplif
{
	class Vec4 {
	private:
		real elt[4];

	protected:
		inline void copy(const Vec4& v);

	public:
		//
		// Standard constructors
		//
		Vec4(real x=0, real y=0, real z=0, real w=0) {
		elt[0]=x; elt[1]=y; elt[2]=z; elt[3]=w;
		}
	#ifdef GFXMATH_VEC3_INCLUDED
		Vec4(const Vec3& v,real w) {elt[0]=v[0];elt[1]=v[1];elt[2]=v[2];elt[3]=w;}
	#endif
		Vec4(const Vec4& v) { copy(v); }
		Vec4(const real *v) { elt[0]=v[0]; elt[1]=v[1]; elt[2]=v[2]; elt[3]=v[3]; }

		//
		// Access methods
		//
	#ifdef SAFETY
		real& operator()(int i)       { assert(i>=0 && i<4); return elt[i]; }
		real  operator()(int i) const { assert(i>=0 && i<4); return elt[i]; }
	#else
		real& operator()(int i)       { return elt[i]; }
		real  operator()(int i) const { return elt[i]; }
	#endif
		real& operator[](int i)             { return elt[i]; }
		const real& operator[](int i) const { return elt[i]; }

		real *raw()             { return elt; }
		const real *raw() const { return elt; }

		//
		// Comparison methods
		//
		inline bool operator==(const Vec4&) const;
		inline bool operator!=(const Vec4&) const;

		//
		// Assignment and in-place arithmetic methods
		//
		inline void set(real x, real y, real z, real w){
		elt[0]=x; elt[1]=y; elt[2]=z; elt[3]=w;
		}
		inline Vec4& operator=(const Vec4& v);
		inline Vec4& operator+=(const Vec4& v);
		inline Vec4& operator-=(const Vec4& v);
		inline Vec4& operator*=(real s);
		inline Vec4& operator/=(real s);

		//
		// Binary arithmetic methods
		//
		inline Vec4 operator+(const Vec4& v) const;
		inline Vec4 operator-(const Vec4& v) const;
		inline Vec4 operator-() const;

		inline Vec4 operator*(real s) const;
		inline Vec4 operator/(real s) const;
		inline real operator*(const Vec4& v) const;
	};



	////////////////////////////////////////////////////////////////////////
	//
	// Method definitions
	//

	inline void Vec4::copy(const Vec4& v)
	{
		elt[0]=v.elt[0]; elt[1]=v.elt[1]; elt[2]=v.elt[2]; elt[3]=v.elt[3];
	}

	inline bool Vec4::operator==(const Vec4& v) const
	{
		real dx=elt[X]-v[X],  dy=elt[Y]-v[Y],  dz=elt[Z]-v[Z],  dw=elt[W]-v[W];
		return (dx*dx + dy*dy + dz*dz + dw*dw) < FEQ_EPS2;
	}

	inline bool Vec4::operator!=(const Vec4& v) const
	{
		real dx=elt[X]-v[X],  dy=elt[Y]-v[Y],  dz=elt[Z]-v[Z],  dw=elt[W]-v[W];
		return (dx*dx + dy*dy + dz*dz + dw*dw) > FEQ_EPS2;
	}

	inline Vec4& Vec4::operator=(const Vec4& v)
	{
		copy(v);
		return *this;
	}

	inline Vec4& Vec4::operator+=(const Vec4& v)
	{
		elt[0] += v[0];   elt[1] += v[1];   elt[2] += v[2];   elt[3] += v[3];
		return *this;
	}

	inline Vec4& Vec4::operator-=(const Vec4& v)
	{
		elt[0] -= v[0];   elt[1] -= v[1];   elt[2] -= v[2];   elt[3] -= v[3];
		return *this;
	}

	inline Vec4& Vec4::operator*=(real s)
	{
		elt[0] *= s;   elt[1] *= s;   elt[2] *= s;  elt[3] *= s;
		return *this;
	}

	inline Vec4& Vec4::operator/=(real s)
	{
		elt[0] /= s;   elt[1] /= s;   elt[2] /= s;   elt[3] /= s;
		return *this;
	}

	inline Vec4 Vec4::operator+(const Vec4& v) const
	{
		return Vec4(elt[0]+v[0], elt[1]+v[1], elt[2]+v[2], elt[3]+v[3]);
	}

	inline Vec4 Vec4::operator-(const Vec4& v) const
	{
		return Vec4(elt[0]-v[0], elt[1]-v[1], elt[2]-v[2], elt[3]-v[3]);
	}

	inline Vec4 Vec4::operator-() const
	{
		return Vec4(-elt[0], -elt[1], -elt[2], -elt[3]);
	}

	inline Vec4 Vec4::operator*(real s) const
	{
		return Vec4(elt[0]*s, elt[1]*s, elt[2]*s, elt[3]*s);
	}

	inline Vec4 Vec4::operator/(real s) const
	{
		return Vec4(elt[0]/s, elt[1]/s, elt[2]/s, elt[3]/s);
	}

	inline real Vec4::operator*(const Vec4& v) const
	{
		return elt[0]*v[0] + elt[1]*v[1] + elt[2]*v[2] + elt[3]*v[3];
	}

	// Make scalar multiplication commutative
	inline Vec4 operator*(real s, const Vec4& v) { return v*s; }



	////////////////////////////////////////////////////////////////////////
	//
	// Primitive function definitions
	//

	//
	// Code adapted from VecLib4d.c in Graphics Gems V
	inline Vec4 cross(const Vec4& a, const Vec4& b, const Vec4& c)
	{
		Vec4 result;

		real d1 = (b[Z] * c[W]) - (b[W] * c[Z]);
		real d2 = (b[Y] * c[W]) - (b[W] * c[Y]);
		real d3 = (b[Y] * c[Z]) - (b[Z] * c[Y]);
		real d4 = (b[X] * c[W]) - (b[W] * c[X]);
		real d5 = (b[X] * c[Z]) - (b[Z] * c[X]);
		real d6 = (b[X] * c[Y]) - (b[Y] * c[X]);

		result[X] = - a[Y] * d1 + a[Z] * d2 - a[W] * d3;
		result[Y] =   a[X] * d1 - a[Z] * d4 + a[W] * d5;
		result[Z] = - a[X] * d2 + a[Y] * d4 - a[W] * d6;
		result[W] =   a[X] * d3 - a[Y] * d5 + a[Z] * d6;

		return result;
	}

	inline real norm(const Vec4& v)
	{
		return sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2] + v[3]*v[3]);
	}

	inline real norm2(const Vec4& v)
	{
		return v[0]*v[0] + v[1]*v[1] + v[2]*v[2] + v[3]*v[3];
	}

	inline real length(const Vec4& v) { return norm(v); }

	inline real unitize(Vec4& v)
	{
		real l=norm2(v);
		if( l!=1.0 && l!=0.0 )
		{
		l = sqrt(l);
		v /= l;
		}
		return l;
	}


	////////////////////////////////////////////////////////////////////////
	//
	// Misc. function definitions
	//

/*	inline ostream& operator<<(ostream& out, zVec4& v)
	{
		return
		out << "[" << v[0] << " " << v[1] << " " << v[2] << " " << v[3] << "]";
	}

	inline istream& operator>>(istream& in, Vec4& v)
	{
		return in >> "[" >> v[0] >> v[1] >> v[2] >> v[3] >> "]";
	}
*/
	#ifdef GFXGL_INCLUDED
	inline void glV(const Vec4& v) { glVertex(v[X], v[Y], v[Z], v[W]); }
	inline void glC(const Vec4& v) { glColor(v[X], v[Y], v[Z], v[W]); }
	#endif
}

// GFXMATH_VEC4_INCLUDED
#endif