bool CWeapon::AdjustTargetVectorLength(
CUnit* targetUnit,
float3& targetPos,
float3& targetVec,
float3& targetDir)
const {
bool retCode = false;
const float tbScale = math::fabsf(targetBorder);
CollisionVolume* cvOld = targetUnit->collisionVolume;
CollisionVolume cvNew = CollisionVolume(targetUnit->collisionVolume);
CollisionQuery cq;
// test for "collision" with a temporarily volume
// (scaled uniformly by the absolute target-border
// factor)
cvNew.RescaleAxes(tbScale, tbScale, tbScale);
cvNew.SetTestType(CollisionVolume::COLVOL_HITTEST_DISC);
targetUnit->collisionVolume = &cvNew;
if (CCollisionHandler::DetectHit(targetUnit, weaponMuzzlePos, ZeroVector, NULL)) {
// our weapon muzzle is inside the target unit's volume; this
// means we do not need to make any adjustments to targetVec
targetVec = ZeroVector;
} else {
targetDir.SafeNormalize();
// otherwise, perform a raytrace to find the proper length correction
// factor for non-spherical coldet volumes based on the ray's ingress
// (for positive TB values) or egress (for negative TB values) position;
// this either increases or decreases the length of <targetVec> but does
// not change its direction
cvNew.SetTestType(CollisionVolume::COLVOL_HITTEST_CONT);
// make the ray-segment long enough so it can reach the far side of the
// scaled collision volume (helps to ensure a ray-intersection is found)
//
// note: ray-intersection is NOT guaranteed if the volume itself has a
// non-zero offset, since here we are "shooting" at the target UNIT's
// midpoint
const float3 targetOffset = targetDir * (cvNew.GetBoundingRadius() * 2.0f);
const float3 targetRayPos = targetPos + targetOffset;
if (CCollisionHandler::DetectHit(targetUnit, weaponMuzzlePos, targetRayPos, &cq)) {
if (targetBorder > 0.0f) { targetVec -= (targetDir * ((targetPos - cq.p0).Length())); }
if (targetBorder < 0.0f) { targetVec += (targetDir * ((cq.p1 - targetPos).Length())); }
}
retCode = true;
}
targetUnit->collisionVolume = cvOld;
// true indicates we took the else-branch and targetDir is now normalized
return retCode;
}
