#import "GameScene.h"

#include <math.h>
#include <stdlib.h>
#include <stdio.h>

// smallpt, a Path Tracer by Kevin Beason, 2008
//edited by Blagovest Taskov
namespace /*small pt*/ {
    struct Color {
        float x, y, z, a;
        Color(float x_=0, float y_=0, float z_=0){ x=x_; y=y_; z=z_; a=1.f ;}
        Color operator*(float b) const { return Color(x*b,y*b,z*b); }
        Color operator+(const Color &b) const { return Color(x+b.x,y+b.y,z+b.z); }
    };

    struct Vec {        // Usage: time ./smallpt 5000 && xv image.ppm
        double x, y, z;                  // position, also color (r,g,b)
        Vec(double x_=0, double y_=0, double z_=0){ x=x_; y=y_; z=z_; }
        Vec operator+(const Vec &b) const { return Vec(x+b.x,y+b.y,z+b.z); }
        Vec operator-(const Vec &b) const { return Vec(x-b.x,y-b.y,z-b.z); }
        Vec operator*(double b) const { return Vec(x*b,y*b,z*b); }
        Vec mult(const Vec &b) const { return Vec(x*b.x,y*b.y,z*b.z); }
        Vec& norm(){ return *this = *this * (1/sqrt(x*x+y*y+z*z)); }
        double dot(const Vec &b) const { return x*b.x+y*b.y+z*b.z; } // cross:
        Vec operator%(Vec&b){return Vec(y*b.z-z*b.y,z*b.x-x*b.z,x*b.y-y*b.x);}
    };
    struct Ray { Vec o, d; Ray(Vec o_, Vec d_) : o(o_), d(d_) {} };
    enum Refl_t { DIFF, SPEC, REFR };  // material types, used in radiance()
    struct Sphere {
        double rad;       // radius
        Vec p, e, c;      // position, emission, color
        Refl_t refl;      // reflection type (DIFFuse, SPECular, REFRactive)
        Sphere(double rad_, Vec p_, Vec e_, Vec c_, Refl_t refl_):
        rad(rad_), p(p_), e(e_), c(c_), refl(refl_) {}
        double intersect(const Ray &r) const { // returns distance, 0 if nohit
            Vec op = p-r.o; // Solve t^2*d.d + 2*t*(o-p).d + (o-p).(o-p)-R^2 = 0
            double t, eps=1e-4, b=op.dot(r.d), det=b*b-op.dot(op)+rad*rad;
            if (det<0) return 0; else det=sqrt(det);
            return (t=b-det)>eps ? t : ((t=b+det)>eps ? t : 0);
        }
    };
    Sphere spheres[] = {//Scene: radius, position, emission, color, material
        Sphere(1e5, Vec( 1e5+1,40.8,81.6), Vec(),Vec(.75,.25,.25),DIFF),//Left
        Sphere(1e5, Vec(-1e5+99,40.8,81.6),Vec(),Vec(.25,.25,.75),DIFF),//Rght
        Sphere(1e5, Vec(50,40.8, 1e5),     Vec(),Vec(.75,.75,.75),DIFF),//Back
        Sphere(1e5, Vec(50,40.8,-1e5+170), Vec(),Vec(),           DIFF),//Frnt
        Sphere(1e5, Vec(50, 1e5, 81.6),    Vec(),Vec(.75,.75,.75),DIFF),//Botm
        Sphere(1e5, Vec(50,-1e5+81.6,81.6),Vec(),Vec(.75,.75,.75),DIFF),//Top
        Sphere(16.5,Vec(27,16.5,47),       Vec(),Vec(1,1,1)*.999, SPEC),//Mirr
        Sphere(16.5,Vec(73,16.5,78),       Vec(),Vec(1,1,1)*.999, REFR),//Glas
        Sphere(600, Vec(50,681.6-.27,81.6),Vec(12,12,12),  Vec(), DIFF) //Lite
    };
    inline double clamp(double x){ return x<0 ? 0 : x>1 ? 1 : x; }
    inline int toInt(double x){ return int(pow(clamp(x),1/2.2)*255+.5); }
    inline bool intersect(const Ray &r, double &t, int &id){
        double n=sizeof(spheres)/sizeof(Sphere), d, inf=t=1e20;
        for(int i=int(n);i--;) if((d=spheres[i].intersect(r))&&d<t){t=d;id=i;}
        return t<inf;
    }
    Vec radiance(const Ray &r, int depth, unsigned short *Xi){
        double t;                               // distance to intersection
        int id=0;                               // id of intersected object
        if (!intersect(r, t, id)) return Vec(); // if miss, return black
        const Sphere &obj = spheres[id];        // the hit object
        Vec x=r.o+r.d*t, n=(x-obj.p).norm(), nl=n.dot(r.d)<0?n:n*-1, f=obj.c;
        double p = f.x>f.y && f.x>f.z ? f.x : f.y>f.z ? f.y : f.z; // max refl
        if (++depth>5) if (erand48(Xi)<p) f=f*(1/p); else return obj.e; //R.R.
        if (obj.refl == DIFF){                  // Ideal DIFFUSE reflection
            double r1=2*M_PI*erand48(Xi), r2=erand48(Xi), r2s=sqrt(r2);
            Vec w=nl, u=((fabs(w.x)>.1?Vec(0,1):Vec(1))%w).norm(), v=w%u;
            Vec d = (u*cos(r1)*r2s + v*sin(r1)*r2s + w*sqrt(1-r2)).norm();
            return obj.e + f.mult(radiance(Ray(x,d),depth,Xi));
        } else if (obj.refl == SPEC)            // Ideal SPECULAR reflection
            return obj.e + f.mult(radiance(Ray(x,r.d-n*2*n.dot(r.d)),depth,Xi));
        Ray reflRay(x, r.d-n*2*n.dot(r.d));     // Ideal dielectric REFRACTION
        bool into = n.dot(nl)>0;                // Ray from outside going in?
        double nc=1, nt=1.5, nnt=into?nc/nt:nt/nc, ddn=r.d.dot(nl), cos2t;
        if ((cos2t=1-nnt*nnt*(1-ddn*ddn))<0)    // Total internal reflection
            return obj.e + f.mult(radiance(reflRay,depth,Xi));
        Vec tdir = (r.d*nnt - n*((into?1:-1)*(ddn*nnt+sqrt(cos2t)))).norm();
        double a=nt-nc, b=nt+nc, R0=a*a/(b*b), c = 1-(into?-ddn:tdir.dot(n));
        double Re=R0+(1-R0)*c*c*c*c*c,Tr=1-Re,P=.25+.5*Re,RP=Re/P,TP=Tr/(1-P);
        return obj.e + f.mult(depth>2 ? (erand48(Xi)<P ?   // Russian roulette
                                         radiance(reflRay,depth,Xi)*RP:radiance(Ray(x,tdir),depth,Xi)*TP) :
                              radiance(reflRay,depth,Xi)*Re+radiance(Ray(x,tdir),depth,Xi)*Tr);
    }
}

//returns used time in seconds
double raytrace() {
    int w=768, h=1024, samps = 1; // # samples
    Ray cam(Vec(50,52,295.6), Vec(0,-0.042612,-1).norm()); // cam pos, dir
    Vec cx=Vec(w*.5135/h), cy=(cx%cam.d).norm()*.5135, r;
    Color *c=new Color[w*h];


    NSTimeInterval date = [NSDate date].timeIntervalSince1970;

    for (int y=0; y<h; y++){                       // Loop over image rows
        for (unsigned short x=0, Xi[3]={0,0,static_cast<unsigned short>(y*y*y)}; x<w; x++)   // Loop cols
            for (int sy=0, i=(h-y-1)*w+x; sy<2; sy++)     // 2x2 subpixel rows
                for (int sx=0; sx<2; sx++, r=Vec()){        // 2x2 subpixel cols
                    for (int s=0; s<samps; s++){
                        double r1=2*erand48(Xi), dx=r1<1 ? sqrt(r1)-1: 1-sqrt(2-r1);
                        double r2=2*erand48(Xi), dy=r2<1 ? sqrt(r2)-1: 1-sqrt(2-r2);
                        Vec d = cx*( ( (sx+.5 + dx)/2 + x)/w - .5) +
                        cy*( ( (sy+.5 + dy)/2 + y)/h - .5) + cam.d;
                        r = r + radiance(Ray(cam.o+d*140,d.norm()),0,Xi)*(1./samps);
                    } // Camera rays are pushed ^^^^^ forward to start in interior
                    c[i] = c[i] + Color(clamp(r.x),clamp(r.y),clamp(r.z))*.25;
                }
    }

    double result = [NSDate date].timeIntervalSince1970 - date;


    delete[] c;
    return result;
}


namespace /*naive quick sort*/ {
    // The partition function
    int partition(int* input, int p, int r)
    {
        int pivot = input[r];

        while ( p < r )
        {
            while ( input[p] < pivot )
                p++;

            while ( input[r] > pivot )
                r--;

            if ( input[p] == input[r] )
                p++;
            else if ( p < r )
            {
                int tmp = input[p];
                input[p] = input[r];
                input[r] = tmp;
            }
        }

        return r;
    }

    // The quicksort recursive function
    void quicksort(int* input, int p, int r)
    {
        if ( p < r )
        {
            int j = partition(input, p, r);
            quicksort(input, p, j-1);
            quicksort(input, j+1, r);
        }
    }

}

//returns used time in seconds
double sort () {
    const int n = 42000000;

    int* arr = new int[n];

    for (int i =0; i < n; ++i) {
        arr[i] = rand() % (1 << 31);
    }

    NSTimeInterval seconds = [NSDate date].timeIntervalSince1970;

    quicksort(arr, 0, n-1);

    double result = [NSDate date].timeIntervalSince1970 - seconds;

    delete[] arr;
    return result;
}

//returns used time in seconds
double mem() {
    const int n = 96000000;
    int* arr = new int[n];
    NSTimeInterval seconds = [NSDate date].timeIntervalSince1970;

    for (int i = 0; i < n; ++i) {
        const int i0 = rand() % n;
        const int i1 = rand() % n;
        const int t = arr[i0];
        arr[i0] = arr[i1];
        arr[i1] = t;
    }
    double result = [NSDate date].timeIntervalSince1970 - seconds;

    delete[] arr;
    return result;
}

//returns used time in seconds
double sfu() {
    int di = rand() % 2;
    if (di > 0)
        di = 0;
    NSTimeInterval seconds = [NSDate date].timeIntervalSince1970;

    float t = 0.0;
    for (int i = 0; i < (12000000 + di); ++i) {
        t += sinf(i * 2.718f);
        t -= cosf(cosf(i / 3.1415926f));
        const float acosValue = MAX(-0.5f, MIN(0.5f, t*cosf(i) + 0.995f));
        t = t * 0.196f + acos(acosValue);
        if (fabs(t) > 1e-5f) {
            t /=t;
        }
    }
    if (t == 196.0f) {
        return 0.f;
    }

    double result = [NSDate date].timeIntervalSince1970 - seconds;
    return result;
}

@implementation GameScene

-(void)didMoveToView:(SKView *)view {

    double test0 = raytrace();
    double test1 = sort();
    double test2 = mem();
    double test3 = sfu();

#ifdef TARGET_OS_IPHONE
    [[[UIAlertView alloc] initWithTitle:@"Time" message:[NSString stringWithFormat:@"Raytace : %fs\nSort: %fs\nRand mem access: %fs\nFPU %fs", test0, test1,test2,test3] delegate:self cancelButtonTitle:@"Okay" otherButtonTitles:nil] show];
#else
    NSString* string =[NSString stringWithFormat:@"Raytace : %fs\nSort: %fs\nRand mem access: %fs\nFPU %fs", test0, test1,test2,test3];
    NSAlert *alert = [[NSAlert alloc] init];
    [alert addButtonWithTitle:@"Okay"];
    [alert setMessageText:@"End"];
    [alert setInformativeText:string];
    [alert setAlertStyle:NSWarningAlertStyle];
    if ([alert runModal] == NSAlertFirstButtonReturn) {

    }
#endif

}

-(void)update:(CFTimeInterval)currentTime {

}

@end