random art

#include <iostream>
using namespace std;
#include <time.h>
#include <math.h>
#include <SDL/SDL.h>

#define PI 3.14159265
SDL_Surface* screen = NULL;

int width = 256;
int height = 256;
//start SDL
bool init(){

    if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 ) {
        return false;
    }
    screen = SDL_SetVideoMode( width, height, 32, SDL_SWSURFACE);
    if(!screen){
        return false;
    }
    srand( time(NULL) );

    return true;
}

//make a color
Uint32 color(int r, int g, int b){
    Uint32 c = SDL_MapRGB(screen->format, r, g, b);

    return(c);
}

//make a random number
int randomNum(int min, int max){
    int ranNum = rand() % max + min;
    return(ranNum);
}

void point(float x, float y, Uint32 c){
    SDL_FillRect(screen, &SDL_Rect{x,y,1,1}, c);
}

float avg(long double x, long double y){
    return ((x+y)/2);
}

//SDL_FillRect(screen, &SDL_Rect {x, y, w, h}, color(r, g, b) );
//    SDL_FillRect(screen, &screen->clip_rect, color(0,0,0) );
// sin(PI*_/180)
int main ( int argc, char** argv )
{
    long double r=0;
    long double g=0;
    long double b=0;
    double pi = PI/180;

    if(!init()){
        return(1);
    }

    for(int x=1; x < width; x++){
        //cout << sin(pi*/180)*128+128 << endl;
        for(int y=1; y<height; y++){
            r = avg(sin(x*x), cos(y*y))*sin(pi*x);
            //r = x*x + y*y;
            g = sin(pi*x*cos(pi*y*x));
            b = 0.7*(sin(pi*x*x)*cos(pi*y*y));
            cout << r << endl;
            point(x, y, color(r*128+128,g*128+128, b*128+128));

        }

    }
    SDL_Flip(screen);
    SDL_SaveBMP(screen, "picture");
    SDL_Delay(2000);
    SDL_FreeSurface(screen);
    SDL_Quit();

    return(0);


}