/* set rain particle values */
static void setpartrain(firestruct * fs, rain * r, float dt)
{
r->age += dt;
vadds(r->vel,dt,r->acc);
vadds(r->pos,dt,r->vel);
if(r->pos[0]<fs->min[0])
r->pos[0]=fs->max[0]-(fs->min[0]-r->pos[0]);
if(r->pos[2]<fs->min[2])
r->pos[2]=fs->max[2]-(fs->min[2]-r->pos[2]);
if(r->pos[0]>fs->max[0])
r->pos[0]=fs->min[0]+(r->pos[0]-fs->max[0]);
if(r->pos[2]>fs->max[2])
r->pos[2]=fs->min[2]+(r->pos[2]-fs->max[2]);
vequ(r->oldpos,r->pos);
vadds(r->oldpos,-(r->partLength),r->vel);
if(r->pos[1]<fs->min[1])
setnewrain(fs, r);
}
/* initialise new rain particle */
static void setnewrain(firestruct * fs, rain * r)
{
r->age=0.0f;
vinit(r->acc,0.0f,-0.98f,0.0f);
vinit(r->vel,0.0f,0.0f,0.0f);
r->partLength=0.2f;
vinit(r->oldpos,fs->min[0]+(fs->max[0]-fs->min[0])*vrnd(),
fs->max[1]+0.2f*fs->max[1]*vrnd(),
fs->min[2]+(fs->max[2]-fs->min[2])*vrnd());
vequ(r->pos,r->oldpos);
vadds(r->oldpos,-(r->partLength),r->vel);
r->pos[1]=(fs->max[1]-fs->min[1])*vrnd()+fs->min[1];
r->oldpos[1]=r->pos[1]-r->partLength*r->vel[1];
}
static void
setpart(part * p)
{
float fact;
if (p->p[0][1] < 0.1) {
setnewpart(p);
return;
}
p->v[1] += AGRAV * dt;
vadds(p->p[0], dt, p->v);
vadds(p->p[1], dt, p->v);
vadds(p->p[2], dt, p->v);
p->age++;
if ((p->age) > maxage) {
vequ(p->c[0], blu2);
vequ(p->c[1], blu2);
vequ(p->c[2], blu2);
}
else {
fact = 1.0 / maxage;
vadds(p->c[0], fact, blu2);
vclamp(p->c[0]);
p->c[0][3] = fact * (maxage - p->age);
vadds(p->c[1], fact, blu2);
vclamp(p->c[1]);
p->c[1][3] = fact * (maxage - p->age);
vadds(p->c[2], fact, blu2);
vclamp(p->c[2]);
p->c[2][3] = fact * (maxage - p->age);
}
}
/* set fire particle values */
static void setpart(firestruct * fs, part * p)
{
float fact;
if (p->p[0][1] < 0.1) {
setnewpart(fs, p);
return;
}
p->v[1] += AGRAV * fs->dt;
vadds(p->p[0], fs->dt, p->v);
vadds(p->p[1], fs->dt, p->v);
vadds(p->p[2], fs->dt, p->v);
p->age++;
if ((p->age) > fs->maxage) {
vequ(p->c[0], partcol2);
vequ(p->c[1], partcol2);
vequ(p->c[2], partcol2);
} else {
fact = 1.0 / fs->maxage;
vadds(p->c[0], fact, partcol2);
vclamp(p->c[0]);
p->c[0][3] = fact * (fs->maxage - p->age);
vadds(p->c[1], fact, partcol2);
vclamp(p->c[1]);
p->c[1][3] = fact * (fs->maxage - p->age);
vadds(p->c[2], fact, partcol2);
vclamp(p->c[2]);
p->c[2][3] = fact * (fs->maxage - p->age);
}
}