open_toontown_panda3d/panda/src/collide/collisionHandlerPusher.cxx

286 lines
9.8 KiB
C++

/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file collisionHandlerPusher.cxx
* @author drose
* @date 2002-03-16
*/
#include "collisionHandlerPusher.h"
#include "collisionNode.h"
#include "collisionEntry.h"
#include "collisionPolygon.h"
#include "config_collide.h"
#include "dcast.h"
#include "epvector.h"
TypeHandle CollisionHandlerPusher::_type_handle;
/**
* The ShoveData class is used within
* CollisionHandlerPusher::handle_entries(), to track multiple shoves onto a
* given collider. It's not exported outside this file.
*/
class ShoveData {
public:
LVector3 _vector;
PN_stdfloat _length;
bool _valid;
CollisionEntry *_entry;
};
/**
*
*/
CollisionHandlerPusher::
CollisionHandlerPusher() {
_horizontal = pushers_horizontal;
}
/**
*
*/
CollisionHandlerPusher::
~CollisionHandlerPusher() {
}
/**
* Serializes this object, to implement pickle support.
*/
void CollisionHandlerPusher::
write_datagram(Datagram &dg) const {
CollisionHandlerPhysical::write_datagram(dg);
dg.add_bool(_horizontal);
}
/**
* Restores the object state from the given datagram, previously obtained using
* __getstate__.
*/
void CollisionHandlerPusher::
read_datagram(DatagramIterator &scan) {
CollisionHandlerPhysical::read_datagram(scan);
_horizontal = scan.get_bool();
}
/**
* Called by the parent class after all collisions have been detected, this
* manages the various collisions and moves around the nodes as necessary.
*
* The return value is normally true, but it may be false to indicate the
* CollisionTraverser should disable this handler from being called in the
* future.
*/
bool CollisionHandlerPusher::
handle_entries() {
bool okflag = true;
FromEntries::const_iterator fi;
for (fi = _from_entries.begin(); fi != _from_entries.end(); ++fi) {
const NodePath &from_node_path = (*fi).first;
const Entries &entries = (*fi).second;
Colliders::iterator ci;
ci = _colliders.find(from_node_path);
if (ci == _colliders.end()) {
// Hmm, someone added a CollisionNode to a traverser and gave it this
// CollisionHandler pointer--but they didn't tell us about the node.
collide_cat.error()
<< "CollisionHandlerPusher doesn't know about "
<< from_node_path << ", disabling.\n";
okflag = false;
} else {
ColliderDef &def = (*ci).second;
{
// How to apply multiple shoves from different solids onto the same
// collider? One's first intuition is to vector sum all the shoves.
// However, this causes problems when two parallel walls shove on the
// collider, because we end up with a double shove. We hack around
// this by testing if two shove vectors share nearly the same
// direction, and if so, we keep only the longer of the two.
typedef epvector<ShoveData> Shoves;
Shoves shoves;
Entries::const_iterator ei;
for (ei = entries.begin(); ei != entries.end(); ++ei) {
CollisionEntry *entry = (*ei);
nassertr(entry != nullptr, false);
nassertr(from_node_path == entry->get_from_node_path(), false);
LPoint3 surface_point;
LVector3 normal;
LPoint3 interior_point;
if (!entry->get_all(def._target, surface_point, normal, interior_point)) {
#ifndef NDEBUG
if (collide_cat.is_debug()) {
collide_cat.debug()
<< "Cannot shove on " << from_node_path << " for collision into "
<< entry->get_into_node_path() << "; no normal/depth information.\n";
}
#endif
} else {
// Shove it just enough to clear the volume.
if (!surface_point.almost_equal(interior_point)) {
if (_horizontal) {
normal[2] = 0.0f;
}
// Just to be on the safe size, we normalize the normal vector,
// even though it really ought to be unit-length already (unless
// we just forced it horizontal, above).
normal.normalize();
ShoveData sd;
sd._vector = normal;
sd._length = (surface_point - interior_point).length();
sd._valid = true;
sd._entry = entry;
#ifndef NDEBUG
if (collide_cat.is_debug()) {
collide_cat.debug()
<< "Shove on " << from_node_path << " from "
<< entry->get_into_node_path() << ": " << sd._vector
<< " times " << sd._length << "\n";
}
#endif
shoves.push_back(sd);
}
}
}
if (!shoves.empty()) {
// Now we look for two shoves that are largely in the same
// direction, so we can combine them into a single shove of the same
// magnitude; we also check for two shoves at 90 degrees, so we can
// detect whether we are hitting an inner or an outer corner.
Shoves::iterator si;
for (si = shoves.begin(); si != shoves.end(); ++si) {
ShoveData &sd = (*si);
Shoves::iterator sj;
for (sj = shoves.begin(); sj != si; ++sj) {
ShoveData &sd2 = (*sj);
if (sd2._valid) {
PN_stdfloat d = sd._vector.dot(sd2._vector);
if (collide_cat.is_debug()) {
collide_cat.debug()
<< "Considering dot product " << d << "\n";
}
if (d > 0.9) {
// These two shoves are largely in the same direction; save
// the larger of the two.
if (sd2._length < sd._length) {
sd2._valid = false;
} else {
sd._valid = false;
}
} else {
// These two shoves are not in the same direction. If they
// are both from polygons that are a child of the same node,
// try to determine the shape of the corner (convex or
// concave).
const CollisionSolid *s1 = sd._entry->get_into();
const CollisionSolid *s2 = sd2._entry->get_into();
if (s1 != nullptr &&
s2 != nullptr &&
s1->is_of_type(CollisionPolygon::get_class_type()) &&
s2->is_of_type(CollisionPolygon::get_class_type()) &&
sd._entry->get_into_node_path() ==
sd2._entry->get_into_node_path()) {
const CollisionPolygon *p1 = DCAST(CollisionPolygon, s1);
const CollisionPolygon *p2 = DCAST(CollisionPolygon, s2);
if (p1->dist_to_plane(p2->get_collision_origin()) < 0 &&
p2->dist_to_plane(p1->get_collision_origin()) < 0) {
// Each polygon is behind the other one. That means we
// have a convex corner, and therefore we should discard
// one of the shoves (or the user will get stuck coming
// at a convex corner).
if (collide_cat.is_debug()) {
collide_cat.debug()
<< "Discarding shove from convex corner.\n";
}
// This time, unlike the case of two parallel walls
// above, we discard the larger of the two shoves, not
// the smaller. This is because as we slide off the
// convex corner, the wall we are sliding away from will
// get a bigger and bigger shove--and we need to keep
// ignoring the same wall as we slide.
if (sd2._length < sd._length) {
sd._valid = false;
} else {
sd2._valid = false;
}
}
}
}
}
}
}
// Now we can determine the net shove.
LVector3 net_shove(0.0f, 0.0f, 0.0f);
LVector3 force_normal(0.0f, 0.0f, 0.0f);
for (si = shoves.begin(); si != shoves.end(); ++si) {
const ShoveData &sd = (*si);
if (sd._valid) {
net_shove += sd._vector * sd._length;
force_normal += sd._vector;
}
}
#ifndef NDEBUG
if (collide_cat.is_debug()) {
collide_cat.debug()
<< "Net shove on " << from_node_path << " is: "
<< net_shove << "\n";
}
#endif
// This is the part where the node actually gets moved:
CPT(TransformState) trans = def._target.get_transform();
LVecBase3 pos = trans->get_pos();
pos += net_shove * trans->get_mat();
def._target.set_transform(trans->set_pos(pos));
def.updated_transform();
// We call this to allow derived classes to do other fix-ups as they
// see fit:
apply_net_shove(def, net_shove, force_normal);
apply_linear_force(def, force_normal);
}
}
}
}
return okflag;
}
/**
* This is an optional hook for derived classes to do some work with the
* ColliderDef and the force vector.
*/
void CollisionHandlerPusher::
apply_net_shove(ColliderDef &def, const LVector3 &net_shove,
const LVector3 &force_normal) {
}
/**
* This is an optional hook for derived classes to do some work with the
* ColliderDef and the force vector.
*/
void CollisionHandlerPusher::
apply_linear_force(ColliderDef &def, const LVector3 &force_normal) {
}