zeus/src/COBBox.cpp

130 lines
4.5 KiB
C++

#include "zeus/COBBox.hpp"
namespace zeus {
CAABox COBBox::calculateAABox(const CTransform& worldXf) const {
CAABox ret = CAABox::skInvertedBox;
CTransform trans = worldXf * transform;
static const CVector3f basis[8] = {{1.f, 1.f, 1.f}, {1.f, 1.f, -1.f}, {1.f, -1.f, 1.f}, {1.f, -1.f, -1.f},
{-1.f, -1.f, -1.f}, {-1.f, -1.f, 1.f}, {-1.f, 1.f, -1.f}, {-1.f, 1.f, 1.f}};
CVector3f p = extents * basis[0];
ret.accumulateBounds(trans * p);
p = extents * basis[1];
ret.accumulateBounds(trans * p);
p = extents * basis[2];
ret.accumulateBounds(trans * p);
p = extents * basis[3];
ret.accumulateBounds(trans * p);
p = extents * basis[4];
ret.accumulateBounds(trans * p);
p = extents * basis[5];
ret.accumulateBounds(trans * p);
p = extents * basis[6];
ret.accumulateBounds(trans * p);
p = extents * basis[7];
ret.accumulateBounds(trans * p);
return ret;
}
bool COBBox::OBBIntersectsBox(const COBBox& other) const {
CVector3f v = other.transform.origin - transform.origin;
CVector3f T = CVector3f(v.dot(transform.basis[0]), v.dot(transform.basis[1]), v.dot(transform.basis[2]));
CMatrix3f R;
float ra, rb, t;
for (int i = 0; i < 3; ++i)
for (int k = 0; k < 3; ++k)
R[i][k] = transform.basis[i].dot(other.transform.basis[k]);
for (int i = 0; i < 3; ++i) {
ra = extents[i];
rb = (other.extents[0] * std::fabs(R[i][0])) + (other.extents[1] * std::fabs(R[i][1])) +
(other.extents[2] * std::fabs(R[i][2]));
t = std::fabs(T[i]);
if (t > (ra + rb + FLT_EPSILON))
return false;
}
for (int k = 0; k < 3; ++k) {
ra = (extents[0] * std::fabs(R[0][k])) + (extents[1] * std::fabs(R[1][k])) + (extents[2] * std::fabs(R[2][k]));
rb = other.extents[k];
t = std::fabs(T[0] * R[0][k] + T[1] * R[1][k] + T[2] * R[2][k]);
if (t > (ra + rb + FLT_EPSILON))
return false;
}
/* A0 x B0 */
ra = (extents[1] * std::fabs(R[2][0])) + (extents[2] * std::fabs(R[1][0]));
rb = (other.extents[1] * std::fabs(R[0][2])) + (other.extents[2] * std::fabs(R[0][1]));
t = std::fabs((T[2] * R[1][0]) - (T[1] * R[2][0]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A0 x B1 */
ra = (extents[1] * std::fabs(R[2][1])) + (extents[2] * std::fabs(R[1][1]));
rb = (other.extents[0] * std::fabs(R[0][2])) + (other.extents[2] * std::fabs(R[0][0]));
t = std::fabs((T[2] * R[1][1]) - (T[1] * R[2][1]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A0 x B2 */
ra = (extents[1] * std::fabs(R[2][2])) + (extents[2] * std::fabs(R[1][2]));
rb = (other.extents[0] * std::fabs(R[0][1])) + (other.extents[1] * std::fabs(R[0][0]));
t = std::fabs((T[2] * R[1][2]) - (T[1] * R[2][2]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A1 x B0 */
ra = (extents[0] * std::fabs(R[2][0])) + (extents[2] * std::fabs(R[0][0]));
rb = (other.extents[1] * std::fabs(R[1][2])) + (other.extents[2] * std::fabs(R[1][1]));
t = std::fabs((T[0] * R[2][0]) - (T[2] * R[0][0]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A1 x B1 */
ra = (extents[0] * std::fabs(R[2][1])) + (extents[2] * std::fabs(R[0][1]));
rb = (other.extents[0] * std::fabs(R[1][2])) + (other.extents[2] * std::fabs(R[1][0]));
t = std::fabs((T[0] * R[2][1]) - (T[2] * R[0][1]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A1 x B2 */
ra = (extents[0] * std::fabs(R[2][2])) + (extents[2] * std::fabs(R[0][2]));
rb = (other.extents[0] * std::fabs(R[1][1])) + (other.extents[1] * std::fabs(R[1][0]));
t = std::fabs((T[0] * R[2][2]) - (T[2] * R[0][2]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A2 x B0 */
ra = (extents[0] * std::fabs(R[1][0])) + (extents[1] * std::fabs(R[0][0]));
rb = (other.extents[1] * std::fabs(R[2][2])) + (other.extents[2] * std::fabs(R[2][1]));
t = std::fabs((T[1] * R[0][0]) - (T[0] * R[1][0]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A2 x B1 */
ra = (extents[0] * std::fabs(R[1][1])) + (extents[1] * std::fabs(R[0][1]));
rb = (other.extents[0] * std::fabs(R[2][2])) + (other.extents[2] * std::fabs(R[2][0]));
t = std::fabs((T[1] * R[0][1]) - (T[0] * R[1][1]));
if (t > (ra + rb + FLT_EPSILON))
return false;
/* A2 x B2 */
ra = (extents[0] * std::fabs(R[1][2])) + (extents[1] * std::fabs(R[0][2]));
rb = (other.extents[0] * std::fabs(R[2][1])) + (other.extents[1] * std::fabs(R[2][0]));
t = std::fabs((T[1] * R[0][2]) - (T[0] * R[1][2]));
if (t > (ra + rb + FLT_EPSILON))
return false;
return true;
}
} // namespace zeus