Collision.h

Go to the documentation of this file.

#pragma once
#include "math_types.h"
#include <coal/BV/AABB.h>
#include <coal/BV/OBB.h>
 
namespace candlewick {
 
using coal::AABB;
 
inline Mat4f toTransformationMatrix(const AABB &aabb) {
  Mat4f T = Mat4f::Identity();
  Float3 halfExtents = 0.5f * (aabb.max_ - aabb.min_).cast<float>();
  T.block<3, 3>(0, 0) = halfExtents.asDiagonal();
  T.topRightCorner<3, 1>() = aabb.center().cast<float>();
  return T;
}
 
inline Mat4f toTransformationMatrix(const coal::OBB &obb) {
  Mat4f T = Mat4f::Identity();
  auto D = obb.extent.asDiagonal();
  T.block<3, 3>(0, 0) = (obb.axes * D).cast<float>();
  T.topRightCorner<3, 1>() = obb.center().cast<float>();
  return T;
}
 
inline std::array<Float3, 8> getAABBCorners(const AABB &aabb) {
  const Float3 min = aabb.min_.cast<float>();
  const Float3 max = aabb.max_.cast<float>();
 
  return {
      Float3{min.x(), min.y(), min.z()}, // 000
      Float3{max.x(), min.y(), min.z()}, // 100
      Float3{min.x(), max.y(), min.z()}, // 010
      Float3{max.x(), max.y(), min.z()}, // 110
      Float3{min.x(), min.y(), max.z()}, // 001
      Float3{max.x(), min.y(), max.z()}, // 101
      Float3{min.x(), max.y(), max.z()}, // 011
      Float3{max.x(), max.y(), max.z()}, // 111
  };
}
 
inline AABB applyTransformToAABB(const AABB &aabb, const Mat4f &tr_) {
  using coal::CoalScalar;
  auto tr = tr_.cast<CoalScalar>();
  coal::Matrix3s R = tr.topLeftCorner<3, 3>();
  coal::Vec3s t = tr.topRightCorner<3, 1>();
  return coal::translate(coal::rotate(aabb, R), t);
}
 
} // namespace candlewick