1 /*
2 #pragma	lib	"/sys/src/cmd/map/libmap/libmap.a$O"
3 #pragma	src	"/sys/src/cmd/map/libmap"
4 */
5 
6 #define index index0
7 #ifndef PI
8 #define PI	3.1415926535897932384626433832795028841971693993751
9 #endif
10 
11 #define TWOPI (2*PI)
12 #define RAD (PI/180)
13 double	hypot(double, double);	/* sqrt(a*a+b*b) */
14 double	tan(double);		/* not in K&R library */
15 
16 #define ECC .08227185422	/* eccentricity of earth */
17 #define EC2 .006768657997
18 
19 #define FUZZ .0001
20 #define UNUSED 0.0		/* a dummy double parameter */
21 
22 struct coord {
23 	double l;	/* lat or lon in radians*/
24 	double s;	/* sin */
25 	double c;	/* cos */
26 };
27 struct place {
28 	struct coord nlat;
29 	struct coord wlon;
30 };
31 
32 typedef int (*proj)(struct place *, double *, double *);
33 
34 struct index {		/* index of known projections */
35 	char *name;	/* name of projection */
36 	proj (*prog)(double, double);
37 			/* pointer to projection function */
38 	int npar;	/* number of params */
39 	int (*cut)(struct place *, struct place *, double *);
40 			/* function that handles cuts--eg longitude 180 */
41 	int poles;	/*1 S pole is a line, 2 N pole is, 3 both*/
42 	int spheroid;	/* poles must be at 90 deg if nonzero */
43 	int (*limb)(double *lat, double *lon, double resolution);
44 			/* get next place on limb */
45 			/* return -1 if done, 0 at gap, else 1 */
46 };
47 
48 
49 proj	aitoff(void);
50 proj	albers(double, double);
51 int	Xazequalarea(struct place *, double *, double *);
52 proj	azequalarea(void);
53 int	Xazequidistant(struct place *, double *, double *);
54 proj	azequidistant(void);
55 proj	bicentric(double);
56 proj	bonne(double);
57 proj	conic(double);
58 proj	cylequalarea(double);
59 int	Xcylindrical(struct place *, double *, double *);
60 proj	cylindrical(void);
61 proj	elliptic(double);
62 proj	fisheye(double);
63 proj	gall(double);
64 proj	gilbert(void);
65 proj	globular(void);
66 proj	gnomonic(void);
67 int	guycut(struct place *, struct place *, double *);
68 int	Xguyou(struct place *, double *, double *);
69 proj	guyou(void);
70 proj	harrison(double, double);
71 int	hexcut(struct place *, struct place *, double *);
72 proj	hex(void);
73 proj	homing(double);
74 int	hlimb(double*, double*, double resolution);
75 proj	lagrange(void);
76 proj	lambert(double, double);
77 proj	laue(void);
78 proj	lune(double, double);
79 proj	loxodromic(double);	/* not in library */
80 proj	mecca(double);
81 int	mlimb(double*, double*, double resolution);
82 proj	mercator(void);
83 proj	mollweide(void);
84 proj	newyorker(double);
85 proj	ortelius(double, double);	/* not in library */
86 int	Xorthographic(struct place *place, double *x, double *y);
87 proj	orthographic(void);
88 int	olimb(double*, double*, double);
89 proj	perspective(double);
90 int	plimb(double*, double*, double resolution);
91 int	Xpolyconic(struct place *, double *, double *);
92 proj	polyconic(void);
93 proj	rectangular(double);
94 proj	simpleconic(double, double);
95 int	Xsinusoidal(struct place *, double *, double *);
96 proj	sinusoidal(void);
97 proj	sp_albers(double, double);
98 proj	sp_mercator(void);
99 proj	square(void);
100 int	Xstereographic(struct place *, double *, double *);
101 proj	stereographic(void);
102 int	Xtetra(struct place *, double *, double *);
103 int	tetracut(struct place *, struct place *, double *);
104 proj	tetra(void);
105 proj	trapezoidal(double, double);
106 proj	vandergrinten(void);
107 proj	wreath(double, double);	/* not in library */
108 
109 void	findxy(double, double *, double *);
110 void	albscale(double, double, double, double);
111 void	invalb(double, double, double *, double *);
112 
113 #define csqrt map_csqrt	/* conflicts on FreeBSD 5 with gcc builtins */
114 #define cpow map_cpow
115 #define sincos map_sincos
116 
117 void	cdiv(double, double, double, double, double *, double *);
118 void	cmul(double, double, double, double, double *, double *);
119 void	cpow(double, double, double *, double *, double);
120 void	csq(double, double, double *, double *);
121 void	csqrt(double, double, double *, double *);
122 void	ccubrt(double, double, double *, double *);
123 double	cubrt(double);
124 int	elco2(double, double, double, double, double, double *, double *);
125 void	cdiv2(double, double, double, double, double *, double *);
126 void	csqr(double, double, double *, double *);
127 
128 void	orient(double, double, double);
129 void	latlon(double, double, struct place *);
130 void	deg2rad(double, struct coord *);
131 void	sincos(struct coord *);
132 void	normalize(struct place *);
133 void	invert(struct place *);
134 void	norm(struct place *, struct place *, struct coord *);
135 void	printp(struct place *);
136 void	copyplace(struct place *, struct place *);
137 
138 int	picut(struct place *, struct place *, double *);
139 int	ckcut(struct place *, struct place *, double);
140 double	reduce(double);
141 
142 void	getsyms(char *);
143 int	putsym(struct place *, char *, double, int);
144 void	filerror(char *s, char *f);
145 void	error(char *s);
146 int	doproj(struct place *, int *, int *);
147 int	cpoint(int, int, int);
148 int	plotpt(struct place *, int);
149 int	nocut(struct place *, struct place *, double *);
150 
151 extern int (*projection)(struct place *, double *, double *);