// -*- C++ -*-
/*
* Simple MultimEdia LiTerator(SMELT)
* by Chris Xiong 2015
* Math header & implementation
*
* WARNING: This library is in development and interfaces would be very
* unstable.
*
*/
#ifndef SMMATH_H
#define SMMATH_H
#include <cmath>
#include <cstddef>
#define sqr(x) ((x)*(x))
#define EPS 1e-8
#ifndef PI
#define PI 3.14159265358979323846f
#endif
template<class T>const T& min(const T& a,const T& b){return a<b?a:b;}
template<class T>const T& max(const T& a,const T& b){return a>b?a:b;}
class smMath
{
public:
static double deg2rad(double deg){return deg/180.*PI;}
static double rad2deg(double rad){return rad/PI*180.;}
static double clamprad(double a){while(a<0)a+=2*PI;while(a>2*PI)a-=2*PI;return a;}
static double clampdeg(double a){while(a<0)a+=360.;while(a>360)a-=360.;return a;}
};
class smvec2d
{
public:
double x,y;
smvec2d(double _x,double _y){x=_x;y=_y;}
smvec2d(){x=y=.0;}
double l(){return sqrt(sqr(x)+sqr(y));}
void normalize(){double L=l();if(L<EPS)return;x/=L;y/=L;}
smvec2d getNormalized(){double L=l();if(L<EPS)return smvec2d(0,0);return smvec2d(x/L,y/L);}
void swap(){double t=x;x=y;y=t;}
void rotate(double rad){double tx=x*cos(rad)+y*sin(rad),ty=y*cos(rad)-x*sin(rad);x=tx,y=ty;}
smvec2d getRotate(double rad){double tx=x*cos(rad)+y*sin(rad),ty=y*cos(rad)-x*sin(rad);return smvec2d(tx,ty);}
friend smvec2d operator -(smvec2d a,smvec2d b){return smvec2d(a.x-b.x,a.y-b.y);}
friend smvec2d operator +(smvec2d a,smvec2d b){return smvec2d(a.x+b.x,a.y+b.y);}
friend double operator |(smvec2d a,smvec2d b){return a.x*b.x+a.y*b.y;}
friend double operator *(smvec2d a,smvec2d b){return a.x*b.y-b.x*a.y;}
friend smvec2d operator *(double a,smvec2d b){return smvec2d(a*b.x,a*b.y);}
friend smvec2d operator *(smvec2d a,double b){return smvec2d(b*a.x,b*a.y);}
friend double operator ^(smvec2d a,smvec2d b){return (a|b)/a.l()/b.l();}
};
class smvec3d
{
public:
double x,y,z;
smvec3d(double _x,double _y,double _z){x=_x;y=_y;z=_z;}
smvec3d(smvec2d a){x=a.x;y=a.y;z=.0;}
smvec3d(){x=y=z=.0;}
double l(){return sqrt(sqr(x)+sqr(y)+sqr(z));}
void normalize(){double L=l();if(L<EPS)return;x/=L;y/=L;z/=L;}
smvec3d getNormalized(){double L=l();if(L<EPS)return smvec3d(0,0,0);return smvec3d(x/L,y/L,z/L);}
friend smvec3d operator -(smvec3d a,smvec3d b){return smvec3d(a.x-b.x,a.y-b.y,a.z-b.z);}
friend smvec3d operator +(smvec3d a,smvec3d b){return smvec3d(a.x+b.x,a.y+b.y,a.z+b.z);}
friend double operator |(smvec3d a,smvec3d b){return a.x*b.x+a.y*b.y+a.z*b.z;}
friend smvec3d operator *(smvec3d a,smvec3d b){return smvec3d(a.y*b.z-a.z*b.y,a.z*b.x-a.x*b.z,a.x*b.y-a.y*b.x);}
friend smvec3d operator *(double a,smvec3d b){return smvec3d(a*b.x,a*b.y,a*b.z);}
friend smvec3d operator *(smvec3d a,double b){return smvec3d(b*a.x,b*a.y,b*a.z);}
friend double operator ^(smvec3d a,smvec3d b){return (a|b)/a.l()/b.l();}
};
class smMatrix
{
public:
double m[16];
/* sf 0 1 2 3
* 0 00 04 08 12
* 1 01 05 09 13
* 2 02 06 10 14
* 3 03 07 11 15
*/
smMatrix(){for(int i=0;i<16;++i)m[i]=.0;}
smMatrix(const smMatrix ©){for(int i=0;i<16;++i)m[i]=copy.m[i];}
double* operator [](int s){if(s>=0&&s<4)return m+s*4;else return NULL;}
void clear(){for(int i=0;i<16;++i)m[i]=.0;}
void loadIdentity(){clear();m[0]=m[5]=m[10]=m[15]=1.;}
void rotate(double a,double x,double y,double z)
{
if(smvec3d(x,y,z).l()<=EPS)return;
if(fabs(smvec3d(x,y,z).l()-1)>EPS)
{
smvec3d a(x,y,z);a.normalize();
x=a.x;y=a.y;z=a.z;
}
smMatrix tmp;
tmp[0][0]=x*x*(1-cos(a))+cos(a);
tmp[1][0]=x*y*(1-cos(a))-z*sin(a);
tmp[2][0]=x*z*(1-cos(a))+y*sin(a);
tmp[0][1]=y*x*(1-cos(a))+z*sin(a);
tmp[1][1]=y*y*(1-cos(a))+cos(a);
tmp[2][1]=y*z*(1-cos(a))-x*sin(a);
tmp[0][2]=x*z*(1-cos(a))-y*sin(a);
tmp[1][2]=y*z*(1-cos(a))+x*sin(a);
tmp[2][2]=z*z*(1-cos(a))+cos(a);
tmp[3][3]=1;
*this=*this*tmp;
}
void lookat(double *eye,double *at,double *up)
{
smvec3d f=smvec3d(at[0],at[1],at[2])-smvec3d(eye[0],eye[1],eye[2]);f.normalize();
smvec3d UP=smvec3d(up[0],up[1],up[2]);UP.normalize();
smvec3d s=f*UP;smvec3d u=s.getNormalized()*f;
*this[0][0]= s.x;*this[1][0]= s.y;*this[2][0]= s.z;*this[3][0]=0;
*this[0][1]= u.x;*this[1][1]= u.y;*this[2][1]= u.z;*this[3][1]=0;
*this[0][2]=-f.x;*this[1][2]=-f.y;*this[2][2]=-f.z;*this[3][2]=0;
*this[0][3]= 0;*this[1][3]= 0;*this[2][3]= 0;*this[3][3]=1;
}
friend smMatrix operator *(smMatrix a,smMatrix b)
{
smMatrix ret;
for(int i=0;i<4;++i)
for(int j=0;j<4;++j)
for(int k=0;k<4;++k)
ret[i][j]+=a[i][k]*b[k][j];
return ret;
}
friend smvec3d operator *(smMatrix a,smvec3d b)
{
return smvec3d(a[0][0]*b.x+a[1][0]*b.y+a[2][0]*b.z,
a[0][1]*b.x+a[1][1]*b.y+a[2][1]*b.z,
a[0][2]*b.x+a[1][2]*b.y+a[2][2]*b.z);
}
};
#endif
