ref: 909323e92a4e694bff5908e500d8655ac1bbd932
dir: /sys/src/games/galaxy/mkgalaxy.c/
#include <u.h> #include <libc.h> #include <bio.h> #include <draw.h> #include "galaxy.h" Vector o, gv; double d = 100, drand, sz = 25, szrand, v, vrand, av, avrand; int new, c = 1; void quadcalc(Body*, QB, double){} Image *randcol(void){ return nil; } void usage(void) { fprint(2, "Usage: %s [-d dist[±r]]\n\t[-s size[±r]] [-v vel[±r]]\n\t[-av angvel[±r]] [-gv xdir,ydir]\n\t[-o xoff,yoff] [-f file]\n\t[-sq] [-i] size\n", argv0); exits("usage"); } Vector polar(double ang, double mag) { Vector v; v.x = cos(ang)*mag; v.y = sin(ang)*mag; return v; } Vector getvec(char *str) { Vector v; v.x = strtod(str, &str); if(*str != ',') usage(); v.y = strtod(str+1, nil); return v; } double getvals(char *str, double *rand) { Rune r; double val; int i; val = strtod(str, &str); i = chartorune(&r, str); if(r == L'±') *rand = strtod(str+i, nil); else *rand = 0; return val; } #define RAND(r) ((r)*(frand()*2 - 1)) void mkbodies(double lim) { Body *b; Vector p; double x, y; for(x = -lim/2; x < lim/2; x += d) for(y = -lim/2; y < lim/2; y += d) { p.x = x + RAND(drand); p.y = y + RAND(drand); if(c) if(hypot(p.x, p.y) > lim/2) continue; b = body(); b->Vector = p; b->v = polar(frand()*π2, v+RAND(vrand)); b->v.x += gv.x - p.y*(av + RAND(avrand))/1000; b->v.y += gv.y + p.x*(av + RAND(avrand))/1000; b->size = sz + RAND(szrand); } } void main(int argc, char **argv) { static Biobuf bout; Body *b; double lim; int fd; char *a; srand(truerand()); fmtinstall('B', Bfmt); glxyinit(); ARGBEGIN { case 'f': fd = open(EARGF(usage()), OREAD); if(fd < 0) sysfatal("Could not open file %s: %r", *argv); readglxy(fd); close(fd); break; case 'i': readglxy(0); break; case 's': a = EARGF(usage()); switch(a[0]) { case 'q': if(a[1] != '\0') usage(); c = 0; break; default: sz = getvals(a, &szrand); break; } break; case 'a': a = EARGF(usage()); if(a[0] != 'v' || a[1] != '\0') usage(); argc--; argv++; av = getvals(*argv, &avrand); break; case 'g': a = EARGF(usage()); if(a[0] != 'v' || a[1] != '\0') usage(); argc--; argv++; gv = getvec(*argv); break; case 'v': v = getvals(EARGF(usage()), &vrand); break; case 'o': o = getvec(EARGF(usage())); break; case 'd': d = getvals(EARGF(usage()), &drand); break; } ARGEND if(argc != 1) usage(); new = glxy.nb; lim = strtod(*argv, nil); mkbodies(lim); Binit(&bout, 1, OWRITE); for(b = glxy.a; b < glxy.a + new; b++) Bprint(&bout, "%B\n", b); for(b = glxy.a+new; b < glxy.a+glxy.nb; b++) { b->x += o.x; b->y += o.y; Bprint(&bout, "%B\n", b); } Bterm(&bout); exits(nil); }