// SCBUILD.C v1.1 -- builds SIN/COS lookup tables (c)1998 James Shaughnessy
// Written for use with the Sony Net Yaroze (as there's no FPU!)
//
// Compiled on Turbo C++ 3.0 for DOS
//
// Type SCBUILD to generate SINCOS.H file, and then just
// #include "sincos.h" in your programs to access the arrays
//
// SCBUILD n (default: 360) will generate n number of indices to the
// arrays, eg SCBUILD 4096 will create SIN[4096] = {...} etc.
//
// The values are LONG integers and are of the * 4096 order, so to get
// the required effect you MUST use ((value * SIN[angle])>>12)
// where value is the number you're affecting, and angle is the integer
// angle in degrees of the range 0 to n-1
//
// You can easily alter and re-compile this code to generate more custom
// lookup tables -- if you'd like me to do it for you no problemo, just
// email below.  It takes the PlayStation AGES to generate these tables
// so let's never see that "Generating lookup tables, please wait..."
// message EVER again!
// Note the nifty way of getting maximum accuracy for pi...
//
// James Shaughnessy  <james@manc.u-net.com>
// http://www.netyaroze-europe.com/~shaughnj


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


int main(int argc, char *argv[])
{
  FILE *outfile;

  int i, n;
  double value;
  long longvalue;
  double pi = 4.0 * atan(1.0);				// 3.14159265358979858...

  char hdrstr[] = "// Sine/Cosine lookup tables (c)1998 James Shaughnessy\n// Created with SCBUILD v1.1 See http://www.netyaroze-europe.com/~shaughnj\n\n";


  if (argc == 1)
  {
    n = 360;
  }
  else
  {
    n = atoi(argv[1]);					// Get input number

    if (argv[1] == "-h" || argv[1] == "-?" || n < 1 || n > 4096)
    {
      printf("SCBUILD v1.1  Sine/Cosine Lookup-table Builder (c)1998 James Shaughnessy\n");
      printf("For Sony Net Yaroze        See http://www.netyaroze-europe.com/~shaughnj\n");
      printf("Format: SCBUILD [n]  (n = size of arrays  Default: 360  Max: 4096)\n");
      exit(1);
    }
  }

  printf("Format: SCBUILD [n]  (n = size of arrays  Default: 360)\n\n");
  printf("Building SIN[%d] / COS[%d] lookup tables ...\n", n, n);


  outfile = fopen("SINCOS.H", "wt");			// [W]rite [T]ext


  fwrite(hdrstr, strlen(hdrstr), 1, outfile);		// Write hdrstr[]


  // Build SIN lookup table
  fwrite("long SIN[", 9, 1, outfile);			// Write "long SIN["
  fprintf(outfile, "%d", n);				// Write "n"
  fwrite("] = {", 5, 1, outfile);			// Write "] = {"

  for (i=0; i<n; i++) {
    value = sin(i * 2.0 * pi / n);
    longvalue = (long)(4096.0 * value);
    if (!(i%12))
      fwrite("\n", 1, 1, outfile);			// newline (every 12)
    fprintf(outfile, "%d", longvalue);
    if (i<n-1)
      fwrite(", ", 2, 1, outfile);			// comma
  }
  fwrite("\n};\n\n", 5, 1, outfile);                    // struct end


  // Build COS lookup table
  fwrite("long COS[", 9, 1, outfile);			// Write "long COS["
  fprintf(outfile, "%d", n);				// Write "n"
  fwrite("] = {", 5, 1, outfile);			// Write "] = {"

  for (i=0; i<n; i++) {
    value = cos(i * 2.0 * pi / n);
    longvalue = (long)(4096.0 * value);
    if (!(i%12))
      fwrite("\n", 1, 1, outfile);			// newline (every 12)
    fprintf(outfile, "%d", longvalue);
    if (i<n-1)
      fwrite(", ", 2, 1, outfile);			// comma
  }
  fwrite("\n};\n", 4, 1, outfile);                      // struct end


  printf("SINCOS.H created!\n");

  close(outfile);
  return (0);
}