source: tags/initial/GDE/LOOPTOOL/loop.h

#define PRINT_WID 550
#define PRINT_HT 750
#define BASE_TO_BASE_DIST 1.0
#define CW 1
#define CCW -1
#define CWID 5
#define CHT 6
#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif
#define NULL 0
#define PI_val 3.1415926535
#define PI_o2 PI_val / 2
#define TWO_PI 2*PI_val

/*      Text attributed */

#define HILITE 1
#define BOLD 2
#define ITALIC 4
#define LOLITE 8

/*      Constraint types        */

#define ANGULAR 1
#define POSITIONAL 2
#define DISTANCE 3

/*      colors  */
#define BLACK 0
#define MAGENTA 1
#define YELLOW 2
#define BLUE 3
#define CYAN 4
#define GREEN 5
#define RED 6
#define WHITE 7

#define Max(a,b) (a)>(b)?(a):(b)
#define Min(a,b) (a)<(b)?(a):(b)
#define distance(a,b,c,d) sqrt( ((a)-(c))*((a)-(c))+((b)-(d))*((b)-(d)) )
#define sqr(a) ((a)*(a))

typedef struct distanceconstraint
{
        double dist;            /*distance*/
        int pair;               /*pairing partner*/
} Dcon;

typedef struct positionalconstraint
{
        double dx,dy;           /*delta x and y*/
        int pair;               /*pairing partner*/
} Pcon;

typedef struct labelstruct
{
        double dist,dx,dy,x,y;
        char text[80];
        int distflag;
} Label;


typedef struct basestruct
{
        double x,y;             /*position*/
        int rel_loc;            /*location in alignment*/
        int known;              /*is position known?*/
        int pair;               /*pase pair*/
        char nuc;               /*this base (a,g,c,t,u etc)*/
        int dir;                /*direction of traversal*/
        int attr;               /*text attributes*/
        int size;               /*font size*/
        Dcon dforw,dback;       /*distance constraint*/
        Pcon *pos;              /*positional constraints*/
        int posnum;             /*number of positional constraints*/
        int depth;              /*depth of helix nesting*/
        Label *label;           /*label for nucc*/
} Base;

typedef struct sequencestruct
{
        int len;                /*sequence len*/
        char *name;             /*sequence name*/
        char *sequence;         /*base list*/
}Sequence;

typedef struct datasetstruct
{
        int siz;                /*number of taxa (plus helix)*/
        int len;                /*length of ALIGNMENT in bases*/
        Sequence helix;         /*helix information*/
        Sequence taxa[4096];    /*individual taxa*/
} DataSet;

typedef struct loopstackstruct
{
        double dist;            /*distance to LAST base*/
        int nucnum;             /*nucleotide index*/
} LoopStak;