/* IK2PIH tinyloc.c December 28, 2024 calculates locator from lon/lat and vice versa using only 16-bit signed integer data types This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. */ #include /* function prototypes */ int loc(int , int , int , int , int , int , int , int , char *); int pos(char *, int *, int *, int *, int *, int *, int *, int *, int *); /* 'loc' function calculates locator from lon/lat inputs: a = longitude [deg] from 0 to 179 (int) b = longitude [min] from 0 to 59 (int) c = longitude [sec] from 0 to 59 (int) x = 0 for East, 1 for West (int) d = latitude [deg] from 0 to 89 (int) e = latitude [min] from 0 to 59 (int) f = latitude [sec] from 0 to 59 (int) y = 0 for North, 1 for South (int) output: l = 6 char world wide locator (char *) return: 1 if error, 0 if ok */ int loc(int a, int b, int c, int x, int d, int e, int f, int y, char *l) { int h,i,j,k,m,n,p,q,z; /* check inputs: z==0 -> ok */ if((a<0) || (a>179)) z=1; else if((b<0) || (b>59)) z=1; else if((c<0) || (c>59)) z=1; else if((x<0) || (x>1)) z=1; else if((d<0) || (d>89)) z=1; else if((e<0) || (e>59)) z=1; else if((f<0) || (f>59)) z=1; else if((y<0) || (y>1)) z=1; else z=0; if(z==0) { /* convert lon/lat to mins and set origin to AA00AA */ if(x==1) {a=-a; b=-b; c=-c;} p=((180+a)*60)+b; /* lon [min] from AA00AA */ if(y==1) {d=-d; e=-e; f=-f;} q=((90+d)*60)+e; /* lat [min] from AA00AA */ /* calculate world wide locator from coordinates */ h=p/1200; /* 1st letter */ i=q/600; /* 2nd letter */ j=((p/60)-(h*20))/2; /* 1st number */ k=(q/60)-(i*10); /* 2nd number */ m=((p-(h*1200)-(j*120))+(c/60))/5; /* 3rd letter */ n=(((q-(i*600)-(k*60))*2)+(f/30))/5; /* 4th letter */ /* build string */ l[0]='A'+(char)h; l[1]='A'+(char)i; l[2]='0'+(char)j; l[3]='0'+(char)k; l[4]='A'+(char)m; l[5]='A'+(char)n; l[6]='\0'; } return(z); } /* 'pos' function calculates lon/lat from locator input: l = 6 char ww-locator CCNNCC (char *) outputs: a = longitude [deg] from 0 to 179 (int *) b = longitude [min] from 0 to 59 (int *) c = longitude [sec] from 0 to 59 (int *) x = 0 for East, 1 for West (int *) d = latitude [deg] from 0 to 89 (int *) e = latitude [min] from 0 to 59 (int *) f = latitude [sec] from 0 to 59 (int *) y = 0 for North, 1 for South (int *) return: 1 if error, 0 if ok */ int pos(char *l, int *a, int *b, int *c, int *x, int *d, int *e, int *f, int *y) { int h,i,j,k,m,n; int p,q,r,s,t,u,v,w,z; char g; /* convert letters to uppercase if needed */ g='a'-'A'; if((l[0]>='a') && (l[0]<='z')) l[0]=l[0]-g; if((l[1]>='a') && (l[1]<='z')) l[1]=l[1]-g; if((l[4]>='a') && (l[4]<='z')) l[4]=l[4]-g; if((l[5]>='a') && (l[5]<='z')) l[5]=l[5]-g; /* check inputs: z==0 -> ok */ if((l[0]<'A') || (l[0]>'R')) z=1; else if((l[1]<'A') || (l[1]>'R')) z=1; else if((l[2]<'0') || (l[2]>'9')) z=1; else if((l[3]<'0') || (l[3]>'9')) z=1; else if((l[4]<'A') || (l[4]>'X')) z=1; else if((l[5]<'A') || (l[5]>'X')) z=1; else z=0; if(z==0) { h=(int)(l[0]-'A'); i=(int)(l[1]-'A'); j=(int)(l[2]-'0'); k=(int)(l[3]-'0'); m=(int)(l[4]-'A'); n=(int)(l[5]-'A'); /* lon/lat in minutes, origin in AA00AA */ p=(h*1200+j*120+m*5); q=((i*600+k*60)*2)+(n*5); /* centre to 0,0 */ p=p-10800; q=q-10800; /* double and adjust to middle of square */ p*=2; q*=2; p+=5; q+=5; if(p<0) *x=1; else *x=0; if(q<0) *y=1; else *y=0; /* calculates longitude in DMS */ r=p/120; s=(p-(r*120))/2; if(r<0) *a=-r; else *a=r; if(s<0) *b=-s; else *b=s; t=(p-(r*120)-(s*2))*30; if(t<0) *c=-t; else *c=t; /* calculates latitude in DMS */ u=q/240; v=(q-(u*240))/4; if(u<0) *d=-u; else *d=u; if(v<0) *e=-v; else *e=v; w=(q-(u*240)-(v*4))*15; if(w<0) *f=-w; else *f=w; } return(z); } /* main program */ int main() { int a,b,c,d,e,f,x,y,z,n; char l[6]; const char k[13]="Wrong input!\0"; do{ do{ putchar('\n'); printf("----------------------\n"); printf("*** IK2PIH TINYLOC ***\n"); printf("----------------------\n"); printf("1. lon/lat to loc\n"); printf("2. loc to lon/lat\n"); printf("3. end\n"); printf("Your choice? [1-2-3]: "); scanf("%d",&z); if((z<1) || (z>3)) fprintf(stderr,"%s\n",k); } while((z<1) || (z>3)); if(z==1) { do{ /* read lon/lat from stdin */ putchar('\n'); printf("Lon(deg)? [ 0;179]: "); scanf("%d",&a); printf("Lon(min)? [ 0; 59]: "); scanf("%d",&b); printf("Lon(sec)? [ 0; 59]: "); scanf("%d",&c); printf("Lon(E/W)? [0=E,1=W]: "); scanf("%d",&x); putchar('\n'); printf("Lat(deg)? [ 0; 89]: "); scanf("%d",&d); printf("Lat(min)? [ 0; 59]: "); scanf("%d",&e); printf("Lat(sec)? [ 0; 59]: "); scanf("%d",&f); printf("Lat(N/S)? [0=N,1=S]: "); scanf("%d",&y); /* calculate locator */ n=loc(a,b,c,x,d,e,f,y,l); if(n==1) fprintf(stderr,"%s\n",k); } while(n==1); /* print locator to stdout */ putchar('\n'); printf("Loc: %s\n",l); } if(z==2) { /* read locator from stdin */ putchar('\n'); do{ printf("loc? [CCNNCC]: "); scanf("%s",l); /* call pos function to calculate coordinates */ n=pos(l,&a,&b,&c,&x,&d,&e,&f,&y); if(n==1) fprintf(stderr,"%s\n",k); } while(n==1); /* print coordinates to stdout */ putchar('\n'); printf("Lon: %d deg %d min %d sec ",a,b,c); if(x==0) printf("E\n"); else printf("W\n"); printf("Lat: %d deg %d min %d sec ",d,e,f); if(y==0) printf("N\n"); else printf("S\n"); } } while(z!=3); return(0); }