metaforce/Runtime/Particle/CFlameWarp.cpp

#include "CFlameWarp.hpp"
#include "CStateManager.hpp"

namespace urde {

void CFlameWarp::ModifyParticles(std::vector<CParticle>& particles) {
  if (x9c_stateMgr == 0 || particles.size() < 9)
    return;

  std::vector<std::pair<float, u8>> vec;
  vec.reserve(particles.size());

  x90_minSize = FLT_MAX;
  x94_maxSize = FLT_MIN;
  float maxTransp = 0.f;
  u8 idx = 0;
  for (CParticle& particle : particles) {
    float transp = 1.f - particle.x34_color.a();
    if (transp > maxTransp) {
      float distSq = (particle.x4_pos - x74_warpPoint).magSquared();
      if (distSq > x8c_maxDistSq && distSq < x98_maxInfluenceDistSq) {
        x8c_maxDistSq = distSq;
        maxTransp = transp;
        x80_floatingPoint = particle.x4_pos;
      }
    }

    if (particle.x2c_lineLengthOrSize < x90_minSize)
      x90_minSize = particle.x2c_lineLengthOrSize;
    if (particle.x2c_lineLengthOrSize > x94_maxSize)
      x94_maxSize = particle.x2c_lineLengthOrSize;

    vec.emplace_back(transp, idx);

    if (xa0_25_collisionWarp) {
      zeus::CVector3f delta = particle.x4_pos - particle.x10_prevPos;
      if (delta.magSquared() >= 0.0011920929f) {
        zeus::CVector3f deltaNorm = delta.normalized();
        zeus::CVector3f behindPos = particle.x10_prevPos - deltaNorm * 5.f;
        zeus::CVector3f fullDelta = particle.x4_pos - behindPos;
        CRayCastResult result = x9c_stateMgr->RayStaticIntersection(
            behindPos, deltaNorm, fullDelta.magnitude(),
            CMaterialFilter::MakeIncludeExclude({EMaterialTypes::Solid}, {EMaterialTypes::ProjectilePassthrough}));
        if (result.IsValid()) {
          float dist = result.GetPlane().pointToPlaneDist(particle.x4_pos);
          if (dist <= 0.f) {
            particle.x4_pos = -result.GetPlane().normal() * dist;
            if (result.GetPlane().normal().dot(particle.x1c_vel) < 0.f) {
              zeus::CVector3f prevStepPos = particle.x4_pos - particle.x1c_vel;
              particle.x4_pos +=
                  (-result.GetPlane().pointToPlaneDist(prevStepPos) / particle.x1c_vel.dot(result.GetPlane().normal()) -
                   1.f) *
                  particle.x1c_vel;
              particle.x1c_vel -= particle.x1c_vel * 0.001f;
            }
          }
        }
      }
    }

    ++idx;
  }

  std::sort(vec.begin(), vec.end(), [](auto& a, auto& b) { return a.first < b.first; });

  for (int i = 0; i < 9; ++i) {
    CParticle& part = particles[vec[i].second];
    x4_vecs[i] = part.x4_pos;
    if (i > 0) {
      zeus::CVector3f delta = x4_vecs[i] - x4_vecs[i - 1];
      if (delta.magnitude() < 0.0011920929f)
        x4_vecs[i] += delta.normalized() * 0.0011920929f;
    }
  }

  x4_vecs[0] = x74_warpPoint;
  x80_floatingPoint = x4_vecs[8];
  xa0_26_processed = true;
}

} // namespace urde