metaforce/Runtime/World/CWorldLight.cpp

#include "Runtime/World/CWorldLight.hpp"

#include <cfloat>

namespace metaforce {
CWorldLight::CWorldLight(CInputStream& in)
: x0_type(EWorldLightType(in.readUint32Big()))
, x4_color(zeus::CVector3f::ReadBig(in))
, x10_position(zeus::CVector3f::ReadBig(in))
, x1c_direction(zeus::CVector3f::ReadBig(in))
, x28_q(in.readFloatBig())
, x2c_cutoffAngle(in.readFloatBig())
, x30_(in.readFloatBig())
, x34_castShadows(in.readBool())
, x38_(in.readFloatBig())
, x3c_falloff(EFalloffType(in.readUint32Big()))
, x40_(in.readFloatBig()) {}

std::tuple<float, float, float> CalculateLightFalloff(EFalloffType falloff, float q) {
  float constant = 0.f;
  float linear = 0.f;
  float quadratic = 0.f;

  if (falloff == EFalloffType::Constant)
    constant = 2.f / q;
  else if (falloff == EFalloffType::Linear)
    linear = 250.f / q;
  else if (falloff == EFalloffType::Quadratic)
    quadratic = 25000.f / q;

  return {constant, linear, quadratic};
}

CLight CWorldLight::GetAsCGraphicsLight() const {
  zeus::CVector3f float_color = x4_color;
  float q = x28_q;
  if (q < FLT_EPSILON)
    q = 0.000001f;

  if (x0_type == EWorldLightType::LocalAmbient) {
    float_color *= zeus::CVector3f(q);
    if (float_color.x() >= 1.f)
      float_color.x() = 1.f;

    if (float_color.y() >= 1.f)
      float_color.y() = 1.f;

    if (float_color.z() >= 1.f)
      float_color.z() = 1.f;

    return CLight::BuildLocalAmbient(x10_position,
                                     zeus::CColor(float_color.x(), float_color.y(), float_color.z(), 1.f));
  } else if (x0_type == EWorldLightType::Directional) {
    return CLight::BuildDirectional(x1c_direction, zeus::CColor{x4_color.x(), x4_color.y(), x4_color.z(), 1.f});
  } else if (x0_type == EWorldLightType::Spot) {
    CLight light =
        CLight::BuildSpot(x10_position, x1c_direction.normalized(),
                          zeus::CColor{x4_color.x(), x4_color.y(), x4_color.z(), 1.f}, x2c_cutoffAngle * .5f);

    const auto [constant, linear, quadratic] = CalculateLightFalloff(x3c_falloff, x28_q);
    light.SetAttenuation(constant, linear, quadratic);
    return light;
  }

  const auto [distC, distL, distQ] = CalculateLightFalloff(x3c_falloff, x28_q);
  return CLight::BuildCustom(x10_position, zeus::CVector3f{0.f, 1.f, 0.f},
                             zeus::CColor{x4_color.x(), x4_color.y(), x4_color.z(), 1.f}, distC, distL, distQ, 1.f, 0.f,
                             0.f);
}
} // namespace metaforce