void Car::applyCollision(const CL_LineSegment2f &p_seg)
{
static const float DAMAGE_MULT = 0.2f;
const float side = -p_seg.point_right_of_line(m_impl->m_position);
const CL_Vec2f segVec = p_seg.q - p_seg.p;
// need front normal (crash side)
CL_Vec2f fnormal(segVec.y, -segVec.x); // right side normal
fnormal.normalize();
if (side < 0) {
fnormal *= -1;
}
// move away
m_impl->m_position += (fnormal * fabs(m_impl->m_speed));
// calculate collision angle to estaminate speed reduction
CL_Angle angleDiff(m_impl->m_phyMoveRot - m_impl->vecToAngle(fnormal));
Workarounds::clAngleNormalize180(&angleDiff);
const float colAngleDeg = fabs(angleDiff.to_degrees()) - 90.0f;
const float reduction = fabs(1.0f - fabs(colAngleDeg - 90.0f) / 90.0f);
// calculate and apply damage
const float damage = m_impl->m_speed * reduction * DAMAGE_MULT;
m_impl->m_damage =
Math::Float::reduce(m_impl->m_damage + damage, 0.0f, 1.0f);
cl_log_event(LOG_DEBUG, "damage: %1, total: %2", damage, m_impl->m_damage);
// reduce speed
m_impl->m_speed -= m_impl->m_speed * reduction;
// bounce movement vector and angle away
// get mirror point
if (m_impl->m_phyMoveVec.length() > 0.01f) {
m_impl->m_phyMoveVec.normalize();
const float lengthProj = m_impl->m_phyMoveVec.length() * cos(segVec.angle(m_impl->m_phyMoveVec).to_radians());
const CL_Vec2f mirrorPoint(segVec * (lengthProj / segVec.length()));
// invert move vector by mirror point
const CL_Vec2f mirrorVec = (m_impl->m_phyMoveVec - mirrorPoint) * -1;
m_impl->m_phyMoveVec = mirrorPoint + mirrorVec;
// update physics angle
m_impl->m_phyMoveRot = m_impl->vecToAngle(m_impl->m_phyMoveVec);
}
}
CL_Angle CarImpl::vecToAngle(const CL_Vec2f &p_vec)
{
const static CL_Vec2f ANGLE_ZERO(1.0f, 0.0f);
CL_Angle angle = p_vec.angle(ANGLE_ZERO);
if (p_vec.y < 0) {
angle.set_radians(-angle.to_radians());
}
return angle;
}