/* Sub- and main programs, fields class nr = 2, d = 0 mod 4,  T J Dekker, 2007.	*/
	/* Draws pictures of prime numbers (red) and prime non-principal ideals (green)	*/
	/* obtained by dividing by non-principal ideal of norm 2.						*/
	/* main program moreover uses subprograms from files quadchar.c and sievquad.c.	*/
	/* DrawUnit.c defines 'Initialize' and, by inclusion, drawing subprograms used.	*/ 

					
	/*    radicands < 100, class nr == 2, bynorm 2 is not norm of principal ideal   
	int bynorm = 2;
	int radicand[]= { -58, -37, -22, -13, -10, -6, -5, 10, 15, 26, 30,   
		  					35, 39, 42, 55, 58, 70, 74, 78, 87, 91, 95, 0 };
	

	/*    radicands < 100, class nr == 2, bynorm 3 is not norm of principal ideal   */
	int bynorm = 3; 
	int radicand[]= {34, 51, 66, 102, 0 };
	 																     
	
	void showitem()
	{	  char it[30]; 
		  RGBForeColor(&blue); sprintf(it, "    prime numbers    "); drawstring(it);
		  RGBForeColor(&green); sprintf(it, "    units    "); drawstring(it);
		  RGBForeColor(&red); sprintf(it, "    prime ideals by norm %d    ", bynorm); 
		  drawstring(it); RGBForeColor(&black);
	}	  /* end showitem */
	
	void drawitem(int x, int y, int norm)
	/* draws prime and unit of field for discriminant discr % 4 == 0 	*/
	{     if (norm >= maxnorm) drawprim(x, y, &black);					/* too large */
	            else if (norm == bynorm) drawprim(x, y, &black); 	/* reject bynorm */
	            else if (inset(norm, prinorm)) drawprim(x, y, &blue); /* primes blue */
	            else if (norm == 1) drawprim(x, y, &green);       /* draw unit green */
	            else    		           /* draw non-principal ideals in red color */
	            if (norm % bynorm == 0 && inset(norm/bynorm, prinorm)) 
	            		drawprim(x, y, &red);
	}     /* end drawitem */