/*
% Integer
& Long
! Single  IEEE 32-bit floating-point numbers
# Double
@ Currency
$ String

*/

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

/*
planisphere.cpp : Defines the entry point for the console
application.;
*/

#include "stdafx.h"

void darc (FILE* dxffile, double x, double y, double r, double ang1,double ang2);
void dcircle (FILE* dxffile, double x, double y, double r);
void dclose( FILE* dxffile );
void dline (FILE* dxffile, double x1, double y1, double x2, double y2);
void dpoint (FILE* dxffile, double x, double y);
void drect (FILE* dxffile, double x1, double y1, double x2, double y2);
FILE* init (FILE* dxffile, char* dxfname);
int parse_yale_dat( char* string, double* r, double* d, double* m );

int main(int argc, char* argv[])
{
   FILE* dxffile = NULL;   
   char dxfname[256];
   double i=0.0;
   double x=0.0, y=0.0, dayang=0.0, ang=0.0, x1=0.0, y1=0.0;
   FILE* yalefile = NULL;
   char yalefilename[] = "yale.dat";
   #define LINE_SIZE 1024
   char line[LINE_SIZE];
   double r=0.0, d=0.0, m=0.0, polar=0.0, ra=0.0, magn=0.0;
   double tand=0.0, dec=0.0;

   /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
     Draws a planisphere in three files. Lowest latitude with current
     grid is 37.5N. Extend the polar angle range to reach lower latitudes.
     Issues remaining - constellations, asterisms and star chart grids
     Month tick marks on the days scale
     The whole issue of labelling - might take me back to CorrelScript
   */

   /* constants */
   const double PI = 4.0 * atan(1.0);
   const double RADS = PI / 180.0;
   const double DEGS = 180.0 / PI;
   const double PHI = 52.5 * RADS;     /*Alter this value for different latitudes */
   const double COTPHI = 1.0 / tan(PHI);

   strcpy( dxfname, "grid.dxf" );
   dxffile = init(dxffile, dxfname);

   drect(dxffile, 0.0, 0.0, 300.0, 300.0);

   /*
     azimuthal projection - plot circles centred on celestial pole
     spaced equally by declination - distortion near horizon...
   */
   for( i=10.0; i<=150.0; i+=10.0 ) { /*FOR i = 10 TO 150 STEP 10; */
      dcircle(dxffile, 150.0, 150.0, i);
        } /* NEXT i */

   /*draw the RA lines */
   for( i=0.0; i<= 23.0; i+=1.0 ) { /*FOR i = 0 TO 23; */
      x = 150.0 * cos(15.0 * RADS * i);
      y = 150.0 * sin(15.0 * RADS * i);
      dline(dxffile, 150.0, 150.0, 150.0 + x, 150.0 + y);
        } /*NEXT i */

   /*
     Now add a circle showing the days on the outer
     rim of the grid;
   */
   dcircle(dxffile, 150.0, 150.0, 147.0);
   dayang = 360.0 / 365.25;
   for( i=0.0; i<= 365.25; i+=1.0 ) { /*FOR i = 0 TO 365.25; */
      ang = i * dayang * RADS;
      x1 = 147.0 * cos(ang);
      y1 = 147.0 * sin(ang);
      x = 150.0 * cos(ang);
      y = 150.0 * sin(ang);
      dline(dxffile, 150.0 + x1, 150.0 + y1, 150.0 + x, 150.0 + y);
        } /*NEXT i */

   /*close the grid file */
   dclose(dxffile);

   /*print the 'stars' layer */
   strcpy( dxfname, "stars.dxf" );
   dxffile = init(dxffile, dxfname);
   /*plot a box round drawing to make PSP import work OK */
   drect(dxffile, 0.0, 0.0, 300.0, 300.0);

   /*plot a circle same size as the base grid circumference */
   dcircle(dxffile, 150.0, 150.0, 150.0);

   /*plot a cross in the centre of the stars layer */
   dline(dxffile, 148.0, 150.0, 152.0, 150.0);
   dline(dxffile, 150.0, 148.0, 150.0, 152.0);

   /*plot 907 stars read from a file called yale.dat */
   if( (yalefile  = fopen( yalefilename, "r" )) == NULL ) {
      fprintf( stderr, "The file %s was not opened\n", yalefilename );
      dclose(dxffile);
      exit( -1 );
        }
   while( !feof(yalefile) ) { /* DO WHILE NOT EOF(2); */
      if( fgets( line, LINE_SIZE, yalefile ) == NULL)
         break;
      if( (parse_yale_dat(line,&r,&d,&m)) != 3 ) {
         fprintf( stderr, "Unable to parse line '%s' from %s\n", line, yalefilename );
         fprintf( stderr, "Data appears to be: r=%lf, d=%lf, m=%lf",r, d, m );
         dclose(dxffile);
         exit( -1 );
            }
      polar = 90.0 - d;
      if( polar < 145.0 ) { /*IF polar < 145.0 THEN; */
            ra = r * RADS * 15.0;
            x = -polar * cos(ra); /*fixes flipped map problem */
            y = polar * sin(ra);
            /*what function is best for magnitude?? */
            magn = 0.5 * sqrt(5.0 - m);
            dcircle(dxffile, 150.0 + x, 150.0 + y, magn);
      } /*END IF; */
   }  /*LOOP; */
   fclose( yalefile );

   /*complete the stars file */
   dclose(dxffile);

   /*Now draw the horizon window file */
   strcpy( dxfname, "horizon.dxf" );
   dxffile = init(dxffile, dxfname);
   /*plot a point at extreme of drawing to make PSP import work OK */
   drect(dxffile, 0.0, 0.0, 300.0, 300.0);
   /*
     plot a circle same size as the plate circumference, and one
     to act as inner ring for hours;
   */
   dcircle(dxffile, 150.0, 150.0, 147.0);
   dcircle(dxffile, 150.0, 150.0, 143.0);

   /*plot a cross in the centre of the plate */
   dline(dxffile, 145.0, 150.0, 155.0, 150.0);
   dline(dxffile, 150.0, 145.0, 150.0, 155.0);

   /*
     plot line segments that outline the horizon...
     set up the zeroth point
   */
   tand = COTPHI * cos(RADS * 0);
   dec = atan(tand);
   polar = 90 - dec * DEGS;
   x = polar * cos(RADS * 0);
   y = polar * sin(RADS * 0);
   /*calculate the rest; */
   for( i=0.0; i<=360.0; i+=1.0 ) { /*FOR i = 1 TO 360; */
      tand = COTPHI * cos(RADS * i);
      dec = atan(tand);
      polar = 90 - dec * DEGS;
      x1 = polar * cos(RADS * i);
      y1 = polar * sin(RADS * i);
      dline(dxffile, 150.0 + x, 150.0 + y, 150.0 + x1, 150.0 + y1);
      x = x1;
      y = y1;
   } /*NEXT i */

   /*
     Now add a circle showing the hours from midnight
     This could be done in the loop above, but its easier
     to see what's going on having a separate one...
     This circle is a little smaller than the base circle
   */
   for( i=0.0; i<=23.0; i+=1.0 ) { /*FOR i = 0 TO 23; */
      ang = RADS * 15 * i;
      x1 = 143 * cos(ang);
      y1 = 143 * sin(ang);
      x = 147 * cos(ang);
      y = 147 * sin(ang);
      dline(dxffile, 150.0 + x1, 150.0 + y1, 150.0 + x, 150.0 + y);
   } /*NEXT i */

   /*finish the plate */
   dclose(dxffile);

} /*   END; */

   /*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */

/*
  adds arc of radius r and centre (x,y), starting at
  ang1 in degrees and ending at ang2 degrees to
  current list of entities
*/
void darc (FILE* dxffile, double x, double y, double r, double ang1,
double ang2)
{
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "ARC" );
   fprintf( dxffile, "%d\n", 10 );
   fprintf( dxffile, "%lf\n", x );
   fprintf( dxffile, "%d\n", 20 );
   fprintf( dxffile, "%lf\n", y );
   fprintf( dxffile, "%d\n", 30 );
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%d\n", 40 );
   fprintf( dxffile, "%lf\n", r );
   fprintf( dxffile, "%d\n", 50 );
   fprintf( dxffile, "%lf\n", ang1 );
   fprintf( dxffile, "%d\n", 51 );
   fprintf( dxffile, "%lf\n", ang2 );
}

/*
  adds a circle of radius r and centre (x,y) to current
  list of entities
*/
void dcircle (FILE* dxffile, double x, double y, double r)
{
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "CIRCLE" );
   fprintf( dxffile, "%d\n", 10 );
   fprintf( dxffile, "%lf\n", x );
   fprintf( dxffile, "%d\n", 20 );
   fprintf( dxffile, "%lf\n", y );
   fprintf( dxffile, "%d\n", 30 );
   fprintf( dxffile, "%lf\n", 0 );
   fprintf( dxffile, "%d\n", 40 );
   fprintf( dxffile, "%lf\n", r );
}

/*
  closes the entities list (ENDSEC) and prints the end of file
  code (EOF), then closes the qbasic disc file.
*/
void dclose( FILE* dxffile )
{
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "ENDSEC" );
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "EOF" );
   fclose( dxffile );
}

/*
   adds a line from (x1,y1) to (x2,y2) to list of entities
*/
void dline (FILE* dxffile, double x1, double y1, double x2, double y2)
{
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "LINE" );
   fprintf( dxffile, "%d\n", 8 );
   fprintf( dxffile, "%s\n", "0" );
   fprintf( dxffile, "%d\n", 10 );
   fprintf( dxffile, "%lf\n", x1 );
   fprintf( dxffile, "%d\n", 20 );
   fprintf( dxffile, "%lf\n", y1 );
   fprintf( dxffile, "%d\n", 30 );
   fprintf( dxffile, "%lf\n", 0.0 );
   fprintf( dxffile, "%d\n", 11 );
   fprintf( dxffile, "%lf\n", x2 );
   fprintf( dxffile, "%d\n", 21 );
   fprintf( dxffile, "%lf\n", y2 );
   fprintf( dxffile, "%d\n", 31 );
   fprintf( dxffile, "%lf\n", 0.0 );
}

/*
  adds a point to entities at absolute coordinates (x,y)
*/
void dpoint (FILE* dxffile, double x, double y)
{
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "POINT" );
   fprintf( dxffile, "%d\n", 10 );
   fprintf( dxffile, "%lf\n", x );
   fprintf( dxffile, "%d\n", 20 );
   fprintf( dxffile, "%lf\n", y );
   fprintf( dxffile, "%d\n", 30 );
   fprintf( dxffile, "%d\n", 0 );
}

/*
  adds a rectangle of bottom left corner x1, y1 and
  top right corner x2, y2 to current list of entities
*/
void drect (FILE* dxffile, double x1, double y1, double x2, double y2)
{
   dline(dxffile, x1, y1, x1, y2);
   dline(dxffile, x1, y2, x2, y2);
   dline(dxffile, x2, y2, x2, y1);
   dline(dxffile, x2, y1, x1, y1);
};

/*
  opens the file and sets up the first few lines of the
  dxf file
*/
FILE* init (FILE* dxffile, char* dxfname)
{
   if( (dxffile = fopen( dxfname, "w+" )) == NULL ) {
      fprintf( stderr, "The file %s was not opened\n", dxfname );
      exit( -1 );
   }
   fprintf( dxffile, "%d\n", 0 );
   fprintf( dxffile, "%s\n", "SECTION" );
   fprintf( dxffile, "%d\n", 2 );
   fprintf( dxffile, "%s\n", "ENTITIES" );

   return( dxffile );
}


/*
   gets r, d, and m from the provided string
*/
int parse_yale_dat( char* string, double* r, double* d, double* m )
{
   int count = 0;
   char seps[]   = " ,\n";
   char *token;

   /* Establish string and get the first token: */
   token = strtok( string, seps );
   for( count=1; count<=3; count++ ) {
      if( token == NULL ) {
         return( count );
      }
      /* assign token to parameter */
      switch( count ) {
         case 1: sscanf(token,"%lf",r); break;
         case 2: sscanf(token,"%lf",d); break;
         case 3: sscanf(token,"%lf",m); break;
      }
      /* Get next token: */
      token = strtok( NULL, seps );
   }
   return( count-1 );
}