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#include <u.h>
#include <libc.h>
#include <ip.h>
#include <draw.h>
#include "libgeometry/geometry.h"
#include "dat.h"
#include "fns.h"
static void
universe_step(Universe *u, double Δt)
{
integrate(u, u->t, Δt);
}
static void
universe_reset(Universe *u)
{
int i, j;
for(i = 0; i < nelem(u->ships); i++){
for(j = 0; j < nelem(u->ships[i].rounds); j++)
memset(&u->ships[i].rounds[j], 0, sizeof(Bullet));
memset(&u->ships[i].Particle, 0, sizeof(Particle));
}
memset(&u->star.Particle, 0, sizeof(Particle));
inituniverse(u);
}
void
inituniverse(Universe *u)
{
int i;
double θ;
Point2 aimstar;
u->star.p = Pt2(0,0,1);
u->star.mass = 5.97e24; /* earth's mass */
θ = ntruerand(360)*DEG;
for(i = 0; i < nelem(u->ships); i++){
θ += i*180*DEG;
Matrix R = {
cos(θ), -sin(θ), 0,
sin(θ), cos(θ), 0,
0, 0, 1
};
u->ships[i].p = addpt2(Pt2(0,0,1), mulpt2(xform(Vec2(1,0), R), 200));
aimstar = subpt2(u->star.p, u->ships[i].p);
u->ships[i].θ = atan2(aimstar.y, aimstar.x);
}
u->ships[0].mass = 10e3; /* 10 tons */
u->ships[0].kind = NEEDLE;
u->ships[0].fuel = 100;
u->ships[1].mass = 40e3; /* 40 tons */
u->ships[1].kind = WEDGE;
u->ships[1].fuel = 200;
}
Universe *
newuniverse(void)
{
Universe *u;
u = emalloc(sizeof(Universe));
memset(u, 0, sizeof *u);
u->step = universe_step;
u->reset = universe_reset;
return u;
}
void
deluniverse(Universe *u)
{
free(u);
}
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