vec3 collide_sphere_sphere(struct sphere_hitbox player, struct sphere_hitbox sphere) {
if (vec3_distance(player.pos, sphere.pos) >= player.r + sphere.r) {
return player.pos;
}
return add_vec3(sphere.pos, mult_vec3(normalize(sub(player.pos, sphere.pos)), player.r + sphere.r));
}
// ************************************************************
// get hit result with a ray.
RTHitResult RTPlane::GetHitResult(RTRay *r) {
/*
Ray = r->vStart + t * r->vDir
and
vNormal dot (vOrigin - vPointOnPlane) = 0.
So substitute the ray equation r(t) in for x and solve for t:
vNormal dot (vOrigin - ray(t)) = 0
vNormal dot (vOrigin - vStart - vDir*t) = 0
vNormal dot (vOrigin - vStart) = (vNormal dot vDir) * t
t = [ vNormal dot (vOrigin - vStart) ] / (vNormal dot vDir)
*/
Vec3 vDirToOrigin = vPos.Sub(r->vStart);
vDirToOrigin.Normalize();
Vec3 vDirNormalized = r->vDir.GetNormalized();
GLfloat numerator = vec3_dot(&vNormal, &vDirToOrigin);
GLfloat denominator = vec3_dot(&vNormal, &vDirNormalized);
GLfloat t = (GLfloat) (numerator / denominator);
RTHitResult hr;
hr.Clear();
// if line wasn't parallel or directly on the plane,
if(t >= 0) {
// find point hit
hr.vPointHit = r->PointAtTValue(t);
// if point hit was at a reasonable distance
if(vec3_distance(&r->vStart, &hr.vPointHit) > 30) {
hr.bHit = false;
return hr;
} else {
// return a hit result containing the point, normal, etc.
hr.bHit = true;
hr.t = t;
hr.vNormalHit = vNormal;
hr.matHit = mat;
}
}
return hr;
}
void RailTrailEffect::tick()
{
if (Options::animation_level <= 0) return;
static const float span = 0.5f; // space between particle layers
static const float spin_span = PI / 8;
const float dist = vec3_distance(this->end, this->start);
const float step = span / (dist);
Vec3 fwd = vec3_sub(this->end, this->start);
//this->start = vec3_add(this->start, vec3_scalar_mult(vec3_normalize(this->start), 0.005f));
// RIGHT SETTINGS WOULD LOOK GOOD ON MOB IMPACTS ---> voxel_explode(this->end, /*min*/ 4, /*max*/ 14, /*size*/ 0.2f, /*force*/ 0.1f, COLOR_GREEN);
float theta, phi;
vec3_to_angles(fwd, &theta, &phi);
float curr_spin = 0.0f;
//float curr_spin = (PI/16) * this->ttl;
for (float fl=0.0f; fl<=1.0f; fl+=step)
{
Vec3 curr = vec3_interpolate(this->start, this->end, fl);
//float r = 0.17f; // quadratic radius
float r = 0.08f; // quadratic radius
Vec3 spiral = vec3_init(
r * cosf(curr_spin),
0,
r * sinf(curr_spin)
);
Vec3 spiral2 = vec3_init(
r * cosf(curr_spin + PI),
0,
r * sinf(curr_spin + PI)
);
spiral = vec3_euler_rotation(spiral, theta-0.5f, 0, phi-0.5f);
spiral2 = vec3_euler_rotation(spiral2, theta-0.5f, 0, phi-0.5f);
spiral = vec3_add(curr, spiral);
spiral2 = vec3_add(curr, spiral2);
spiral = translate_position(spiral);
spiral2 = translate_position(spiral2);
//float anim_scale = float(Options::animation_level)/3.0f;
//n = anim_scale*float(n);
Particle::Shrapnel *s;
s = Particle::create_shrapnel(spiral, /*vel*/ vec3_init(0,0,0));
if (s == NULL) return;
//s->ttl = randrange(8, 15);
//s->scale = 0.1f;
//s->texture_index = 54;
s->ttl = randrange(2, 4);
//s->ttl = 2;
s->scale = 0.06f;
s->texture_index = 22;
s = Particle::create_shrapnel(spiral2, /*vel*/ vec3_init(0,0,0));
if (s == NULL) return;
//s->ttl = randrange(8, 15);
//s->scale = 0.1f;
s->texture_index = 54;
s->ttl = randrange(2, 4);
//s->ttl = 2;
s->scale = 0.06f;
s->texture_index = 22;
//draw_quad(curr, span, theta, phi);
curr_spin += spin_span;
if (curr_spin >= PI*2)
curr_spin = 0.0f;
}
}