void
plMassSet(PLmass *mo, float m,
float cox, float coy, float coz,
float ixx, float iyy, float izz,
float ixy, float ixz, float iyz)
{
memset(mo, 0, sizeof(PLmass));
mo->m = m;
mo->I[0][0] = ixx;
mo->I[1][1] = iyy;
mo->I[2][2] = izz;
mo->I[0][1] = ixy;
mo->I[1][0] = ixy;
mo->I[0][2] = ixz;
mo->I[2][0] = ixz;
mo->I[1][2] = iyz;
mo->I[2][1] = iyz;
mo->cog = vf3_set(cox, coy, coz);
mf3_inv2(mo->I_inv, mo->I);
mo->minMass = 0.0f;
}
void
plStepParticleSystem(PLparticles *ps, float dt)
{
assert(ps != NULL);
if (ps->enabled == false) return;
size_t activeParticles = 0;
for (size_t i = 0 ; i < ps->particleCount ; ++i) {
if (ps->particles[i].active) {
ps->particles[i].p += vf3_s_mul(ps->particles[i].v, dt) + vf3_s_mul(ps->obj->v, dt);
ps->particles[i].age += dt;
activeParticles++;
if (ps->particles[i].age > ps->particles[i].lifeTime) {
ps->particles[i].active = false;
int_array_push(&ps->freeParticles, i);
activeParticles --;
}
}
}
// Auto disable
if (ps->autoDisable) {
if (activeParticles == 0) {
ps->enabled = false;
}
return;
}
// Not off or disabled, emitt new particles
float newPartCount = ps->emissionRate * dt * (1.0 + rand_percent(10));
float intPart;
float frac = modff(newPartCount, &intPart);
unsigned newParticles = (unsigned) intPart;
// The fraction is handled with randomisation
int rval = random() % 128;
if ((float)rval/128.0f < frac) newParticles ++;
for (unsigned i = 0 ; i < newParticles ; ++i) {
if (ps->freeParticles.length > 0) {
int i = int_array_remove(&ps->freeParticles, 0);
ps->particles[i].active = true;
ps->particles[i].age = 0.0;
// Adjust lifetime by +-20 %
ps->particles[i].lifeTime = ps->lifeTime + ps->lifeTime * rand_percent(20);
ps->particles[i].p = v_q_rot(ps->p, ps->obj->q);
ps->particles[i].v = v_q_rot(ps->v * vf3_set(rand_percent(10), rand_percent(10), rand_percent(10)), ps->obj->q);
ps->particles[i].rgb = ps->rgb;
} else {
break;
}
}
}
void
plAttachParticleSystem3f(PLparticles *ps, PLobject *obj, float x, float y, float z)
{
assert(ps != NULL);
assert(obj != NULL);
assert(ps->obj == NULL);
obj_array_push(&obj->psystem, ps);
ps->obj = obj;
if (obj->parent) {
obj_array_push(&obj->parent->sys->world->partSys, ps);
} else {
obj_array_push(&obj->sys->world->partSys, ps);
}
ps->p = vf3_set(x, y, z);
}
/*!
\param a Semi-major axis
\param b Semi-minor axis
\param ecc Eccentricity of orbit
\param GM Gravitational parameter of orbited object GM
\param t Absolute time in seconds.
*/
float3
plOrbitPosAtTime(pl_keplerelems_t *orbit, double GM, double t)
{
long double meanMotion = plMeanMotion(GM, orbit->a);
long double eccAnomaly = pl_ecc_anomaly(orbit->ecc, meanMotion, t);
/* Compute x, y from anomaly, y is pointing in the direction of the
periapsis */
double y = orbit->a * cos(eccAnomaly) - orbit->a * orbit->ecc; // NOTE: on the plane we usually do x = a cos t
double x = -orbit->b * sin(eccAnomaly); // Since we use y as primary axis, x points downwards
quaternion_t q = orbit->qOrbit;
float3 v = vf3_set(x, y, 0.0);
v = v_q_rot(v, q);
assert(isfinite(v.x));
assert(isfinite(v.y));
assert(isfinite(v.z));
return v;
}
void
plMassTranslate(PLmass *m, float dx, float dy, float dz)
{
float3x3 re;
mf3_ident(re);
float3 r = vf3_set(dx, dy, dz);
float rdot = vf3_dot(r, r);
re[0][0] = rdot;
re[1][1] = rdot;
re[2][2] = rdot;
float3x3 rout;
vf3_outprod(rout, r, r);
float3x3 madj;
mf3_sub(madj, re, rout);
float3x3 mtmp;
mf3_s_mul(mtmp, madj, m->m);
mf3_add2(m->I, mtmp);
m->cog = vf3_add(m->cog, r);
mf3_inv2(m->I_inv, m->I);
}
float3
ooGeoEllipseSegPoint(OOellipse *e, double t)
{
double pos = fmod(t, (double)(e->vec.length));
size_t i = (size_t) pos;
float3 a = (float3) e->vec.elems[(i + 1) % e->vec.length];
float3 b = (float3) e->vec.elems[i % e->vec.length];
double frac = pos - floor(pos);
float3 av, bv;
av = a;
bv = b;
// Lineraly interpolate between point b and a
float3 abdiff = vf3_sub(av, bv);
float3 tmp = vf3_set(frac, frac, frac);
float3 fv = vf3_mul(abdiff, tmp);//v_s_mul(abdiff, (float)frac); BUG IN v_s_mul???
float3 res = vf3_add(bv, fv);
return res;
}
void
pl_sys_step(pl_system_t *sys, double dt)
{
// Add gravitational forces
for (size_t i = 0; i < sys->rigidObjs.length ; i ++) {
pl_object_t *obj = sys->rigidObjs.elems[i];
double3 g = pl_bhut_compute_gravity(sys->world->bhut_tree, obj);
pl_object_force3fv(obj, vf3_set(g.x, g.y, g.z));
PL_CHECK_OBJ(obj);
float3 f12 = pl_compute_gravity(sys->orbitalBody, obj);
pl_object_set_gravity3fv(obj, f12);
pl_object_force3fv(obj, f12);
PL_CHECK_OBJ(obj);
if (sys->parent) {
f12 = pl_compute_gravity(sys->parent->orbitalBody, obj);
pl_object_set_gravity3fv(obj, f12);
pl_object_force3fv(obj, f12);
PL_CHECK_OBJ(obj);
}
float3 drag = pl_object_compute_drag(obj);
pl_object_force3fv(obj, drag);
PL_CHECK_OBJ(obj);
pl_object_step(obj, dt);
}
pl_sys_update_current_pos(sys, dt);
for (size_t i = 0; i < sys->orbits.length ; i ++) {
pl_sys_step(sys->orbits.elems[i], dt);
}
}
void
plSetEmitterDirection3f(PLparticles *ps, float x, float y, float z)
{
ps->v = vf3_set(x, y, z);
}
void
pl_object_clear_(pl_object_t *obj)
{
obj->f_ack = vf3_set(0.0f, 0.0f, 0.0f);
obj->t_ack = vf3_set(0.0f, 0.0f, 0.0f);
}