/* Subprograms and main program, discriminant = 1 mod 4, 	T. J. Dekker, 2007.		*/
/* Draws pictures of prime numbers (blue) and prime non-principal ideals (red). 	*/

int bynorm, shift;
int radicand[] = {          	 /*  non-unique factorization domains, class nr 3:  */ 
		  - 23, - 31, - 59, - 83, -107, -139, -211, -283, -307, -331, -379, -499, 
/*		  -547, -643, -883, -907,  
/*		   229,  257,  321,  469,  473, 
*/		     0}; 
		  
void showitem()
	{	  char it[30]; int i, k; int natp[] = {2, 3, 5, 7, 11, 13};
		  for (i = 0; i < 6 && qchar[natp[i]] <= 0; i++) ; bynorm = natp[i];
		  for (k = 0; k < 100 && QNORM(k, 1) % bynorm != 0; k++) ; shift = k;  
		  RGBForeColor(&blue); sprintf(it, "    prime numbers    ");   drawstring(it);
		  RGBForeColor(&gray); sprintf(it, "    units    ");           drawstring(it);
		  RGBForeColor(&green);   sprintf(it, "    prime ideals ");    drawstring(it);
		  RGBForeColor(&red); sprintf(it, "by norm %d shift %d", bynorm, shift); 
		  drawstring(it); RGBForeColor(&black);
	}	  /* end showitem */

	void drawitem(int x, int y, int norm)
	{	  if   (norm >= maxnorm) drawprim(x, y, &black); 				/*  big   	*/
		  else if (norm == bynorm) drawprim(x, y, &black); 		 /*  reject bynorm  */
	      else if (inset(norm, prinorm)) drawprim (x, y, &blue); 		/*  primes  */
	      else if (norm == 1) drawprim(x, y, &gray); 			   	 	/*  units   */
	      else if (norm % bynorm == 0 && inset(norm/bynorm, prinorm)) 
	      {	     						/*   non-principal ideals in green or red  	*/
	           if (((x+y)/2 + shift * y) % bynorm != 0) drawprim(x, y, &green);
	           else drawprim(x, y, &red);
	      }
	}	  /* end drawitem */ 
	
/*	end of quad1clas3.c  */