/* quadprim1mod4.c for quadratic fields, d = 1 mod 4, T J Dekker, 2007-2013. */
/* Include in quadprimes.c to draw pictures of primes and units in colors.   */
/* Optionally also prime non-principal ideals (co-ideals) are drawn.         */
/* The programs use subprograms from files quadchar.c and quadsiev.c         */
/* and programming environment of Xcode system.                              */

# define FONTSIZE     14          //  size of font for heading
# define SMAX         89          //  (113)  maximum length character to draw	
# define CMIN         30          //  length of heading text

# define AMAX         47          //  (56) getallen x + y tau voor |x| <= AMAX	
# define BMAX         47          //  (50)                 en voor |y| <= BMAX					
# define DX            8          //  (6) spacing in x direction					
# define DY            7          //  (5) spacing in y direction	
# define H             3          //  half size of diamond 
# define K             2          //  half height of diamond *** new
# define QNORM(x, y)  abs(x*(x+y)+y*y*(1-discriminant)/4) // norm of x + y tau
# define peri         period/2+1  //  to draw chi over half double period +1

# define ideal                    //  empty if no co-ideals are drawn
# define testx                    //  empty test
		   		
/*  Select class number either 1, 2, or 3, and corresponding radicand row.
Moreover, optional include to draw prime co-ideals.
*/

 int clas = 1, radicand[] = {-3,-7,-11,-19,-43,-67,-163, 5, 13, 17, 21, 29};

// int clas = 2, radicand[] = {-15,-35,-51,-91,-115,-123,-403,-427, 65, 85};
// # include "quadideal2.c"

// int clas = 3, radicand[] = {-23,-31,-59,-83,-107,-139,-211,-907, 229, 257};
// # include "quadideal3.c"

void drawdiamond(int x, int y) /* draws diamond of size 2H, center (x, y) */
{	CGContextMoveToPoint(c, x-H, y-K); AddLineToPoint(x-H, y+K);
	AddLineToPoint(x, y+2*K); AddLineToPoint(x+H, y+K);
	AddLineToPoint(x+H, y-K);
	AddLineToPoint(x, y-2*K); AddLineToPoint(x-H, y-K);
	CGContextFillPath(c); 	
}   /*  end drawdiamond  */

void picture() /* draws picture of primes, units and option prime ideals */
{   int xo, yo, a, b, norm, ab;	
	xo = X00 + DX * AMAX; yo = yheight - Y00 - DY * BMAX;				 
	for (b = -BMAX; b <= BMAX; b++) 
		for (a = -(2*AMAX+b)/2; a <= (2*AMAX-b)/2; a++)  
		{	norm = QNORM(a, b);	
			if (norm >= maxnorm) FillBlack; // big black
			else if (inset(norm, prinorm)) FillBlue; // primes
			else if (norm == 1) FillRed; // units
			testx  // optional extra test for co-ideals
			else goto nodraw; 
			ab = 2 * a + b;  //  to obtain staggered grid
			//  draw diamond at given central coordinates:
			drawdiamond(DX * ab / 2 + xo, DY * b + yo);			
		nodraw: ;
		}
}   /*  end picture  */