chaosd - random sierpinski fractal generator

#include <stdio.h>
#include <stdlib.h> // rand()
#include <math.h>  // rint()
#include <jpeglib.h>
//fixed. should be parsed from commandline or defaulted to max screen dimensions
#define xmax 1024
#define ymax 768

//unused yet. should be parsed from chaos.conf file somewhere in /local/share/ or smth.
//dimensions of vga screen
#define dxmax 320
#define dymax 240
#define vgamode 'G640x480x16'

unsigned char ns=12;
int xnn=0,ynn=0,xp=0,yp=0,xk=0,yk=0,dx=0,dy=0,x=0,y=0;
float s11[50], p[50],
s12[50],
s13[50],
s23[50],
s22[50],
s21[50],
s31[50],
s41[50];

unsigned char ekran[xmax+1][ymax+1];
unsigned char image_buffer[xmax*ymax+1]; /*JSAMPLE*/
//char vgamode[20]="G640x480x256";
int it ;

double my_rand(float a) {
    return (1+(1.0*a*rand()/(RAND_MAX+1.0)));
}

double my_frand() {
    return (rand()/(RAND_MAX+1.0));
}

void plot(int a, int b) {
        ekran[a][b]++;
}
  void cls() { int i,j;
    for(i=0;i<xmax;i++){
        for(j=0;j<ymax;j++){
        ekran[i][j]=0;
        }
    }
}

//extern JSAMPLE * image_buffer;    /* Points to large array of R,G,B-order data */
//JSAMPLE * ekran;  /* Points to large array of R,G,B-order data */
//int image_height=xmax;    /* Number of rows in image */
//int image_width=ymax;     /* Number of columns in image */

void write_JPEG_file (char filename[255], int quality)
{ struct jpeg_compress_struct cinfo;
  struct jpeg_error_mgr jerr;
  FILE * outfile;       /* target file */
  JSAMPROW row_pointer[1];  /* pointer to JSAMPLE row[s] */
  int row_stride;       /* physical row width in image buffer */

  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_compress(&cinfo);

  if ((outfile = fopen(filename, "wb")) == NULL) {
    fprintf(stderr, "can't open", filename,".jpg\n"); exit(1);
  }
  jpeg_stdio_dest(&cinfo, outfile);

  cinfo.image_width = xmax;     /* image width and height, in pixels */
  cinfo.image_height = ymax;
  cinfo.input_components = 1;       /* # of color components per pixel */
  cinfo.in_color_space = JCS_GRAYSCALE; /* colorspace of input image */
  jpeg_set_defaults(&cinfo);
  //jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);

  jpeg_start_compress(&cinfo, TRUE);
  row_stride = xmax * 1;    /* JSAMPLEs per row in image_buffer */
  while (cinfo.next_scanline < cinfo.image_height) {
    row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
    (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
  }
  jpeg_finish_compress(&cinfo);
  fclose(outfile);
  jpeg_destroy_compress(&cinfo);
}



void dump(char filename[255]) { int i,j; unsigned char a;
    for(j=0;j<ymax;j++) {
    for(i=0;i<xmax;i++) {
        image_buffer[i+j*xmax]=ekran[i][j];
    }
    }
    write_JPEG_file ("/dev/stdout", 50);
}


void g545() { double a;
    if (xp>xk) { a=xp; xp=xk; xk=a; a=yp; yp=yk; yk=a; }

    dx=fabs(xk-xp); dy=fabs(yk-yp);

    if (dy>dx) {
    if (yp>yk) { a=xp; xp=xk; xk=a; a=yp; yp=yk; yk=a; }

    a=(xk-xp)/(yk-yp);
    for (y=yp;y<=yk;y+=5) {
        x=xp+a*(y-yp);
    } /* next y */
    }
    else {
    if (xp>xk) { a=xp; xp=xk; xk=a; a=yp; yp=yk; yk=a; }

    a=(yk-yp)/(xk-xp);
    for (x=xp;x<=xk;x+=8) { y=yp+a*(x-xp);} /* next x */
    }
}

void g360(){ int i; double r1,r2,r3,xx[5],yy[5];
    for (i=1;i<=ns;i++){
    r1=my_frand()*(xmax);
    r2=my_frand()*(xmax);
    r3=my_frand()*(xmax);

    s11[i]=(r2-r1)/(xmax);
    s12[i]=(r3-r1)/(ymax);
    s13[i]=r1;

    r1=my_frand()*(ymax);
    r2=my_frand()*(ymax);
    r3=my_frand()*(ymax);

    s21[i]=(r2-r1)/(xmax);
    s22[i]=(r3-r1)/(ymax);
    s23[i]=r1;

    xx[0]=   0*s11[i]+   0*s12[i]+s13[i];
    yy[0]=   0*s21[i]+   0*s22[i]+s23[i];
    xx[1]=xmax*s11[i]+   0*s12[i]+s13[i];
    yy[1]=xmax*s21[i]+   0*s22[i]+s23[i];
    xx[2]=xmax*s11[i]+ymax*s12[i]+s13[i];
    yy[2]=xmax*s21[i]+ymax*s22[i]+s23[i];
    xx[3]=   0*s11[i]+ymax*s12[i]+s13[i];
    yy[3]=   0*s21[i]+ymax*s22[i]+s23[i];

    xp=xx[0];
    yp=yy[0];
    xk=xx[1];
    yk=yy[1];

    g545();


    xp=xx[2];
    yp=yy[2];
    xk=xx[1];
    yk=yy[1];

    g545();


    xp=xx[2];
    yp=yy[2];
    xk=xx[3];
    yk=yy[3];

    g545();


    xp=xx[0];
    yp=yy[0];
    xk=xx[3];
    yk=yy[3];

    g545();


    } /* next i */
}


void iteration() {

}


void randomize() {
    ns=2+(int)(15*my_frand());
    it=it*ns;
}




int main(){ int i=0,k=0,a=0,h=0,q=0; float z=0 ;  double pp=0,r=0; char filename[16] ;
    srand((int)time(NULL));
    cls();

    q=0;
    it=10000;
    randomize();
    g360();
    cls();


    pp=0;
    for (i=1;i<=ns;i++) {
    p[i]=fabs(s11[i]*s22[i]-s21[i]*s12[i])+0.3;
    pp+=p[i];
    }

    z=0;
    for (i=1;i<=ns;i++) {
    z=z+p[i];
    p[i]=z/pp;
    }

    x=0;
    ynn=0;
    xnn=0;

    z=0;
    for (r=1;r<(10*ns)*100000;r++) {



    z=rand()/(RAND_MAX+1.0);
    i=1;
//        while (z>=p[i] && i!=ns) {i++;}

    switch(ns%8){
    case 0:     if (z>=p[i]) {i++;};
    case 32:    if (z>=p[i]) {i++;};
    case 31:    if (z>=p[i]) {i++;};
    case 30:    if (z>=p[i]) {i++;};
    case 29:    if (z>=p[i]) {i++;} else goto found;
    case 28:    if (z>=p[i]) {i++;};
    case 27:    if (z>=p[i]) {i++;};
    case 26:    if (z>=p[i]) {i++;};
    case 25:    if (z>=p[i]) {i++;};
    case 24:    if (z>=p[i]) {i++;};
    case 23:    if (z>=p[i]) {i++;};
    case 22:    if (z>=p[i]) {i++;} else goto found;
    case 21:    if (z>=p[i]) {i++;};
    case 20:    if (z>=p[i]) {i++;};
    case 19:    if (z>=p[i]) {i++;};
    case 18:    if (z>=p[i]) {i++;};
    case 17:    if (z>=p[i]) {i++;};
    case 16:    if (z>=p[i]) {i++;};
    case 15:    if (z>=p[i]) {i++;} else goto found;
    case 14:    if (z>=p[i]) {i++;};
    case 13:    if (z>=p[i]) {i++;};
    case 12:    if (z>=p[i]) {i++;};
    case 11:    if (z>=p[i]) {i++;};
    case 10:    if (z>=p[i]) {i++;};
    case 9:     if (z>=p[i]) {i++;};
    case 8:     if (z>=p[i]) {i++;};
    case 7:     if (z>=p[i]) {i++;} else goto found;
    case 6:     if (z>=p[i]) {i++;};
    case 5:     if (z>=p[i]) {i++;};
    case 4:     if (z>=p[i]) {i++;};
    case 3:     if (z>=p[i]) {i++;};
    case 2:     if (z>=p[i]) {i++;};
found:                  }

    x=xnn;
    xnn=xnn*s11[i]+ynn*s12[i]+s13[i];

    ynn=  x*s21[i]+ynn*s22[i]+s23[i];
    //moved x=xnn;
    if (xnn<xmax && xnn>0 & ynn>0 && ynn<ymax) { ekran[(int)xnn][(int)ynn]++; }

    }
    q++; sprintf (filename, "%d.jpg",q) ;dump(filename);

     return 0;
}