overte-HifiExperiments/libraries/physics/src/CharacterController.cpp

572 lines
22 KiB
C++

//
// CharacterControllerInterface.cpp
// libraries/physcis/src
//
// Created by Andrew Meadows 2015.10.21
// Copyright 2015 High Fidelity, Inc.
//
// Distributed under the Apache License, Version 2.0.
// See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//
#include "CharacterController.h"
#include <NumericalConstants.h>
#include "PhysicsCollisionGroups.h"
#include "ObjectMotionState.h"
#include "PhysicsLogging.h"
const btVector3 LOCAL_UP_AXIS(0.0f, 1.0f, 0.0f);
const float JUMP_SPEED = 3.5f;
const float MAX_FALL_HEIGHT = 20.0f;
#ifdef DEBUG_STATE_CHANGE
#define SET_STATE(desiredState, reason) setState(desiredState, reason)
#else
#define SET_STATE(desiredState, reason) setState(desiredState)
#endif
// helper class for simple ray-traces from character
class ClosestNotMe : public btCollisionWorld::ClosestRayResultCallback {
public:
ClosestNotMe(btRigidBody* me) : btCollisionWorld::ClosestRayResultCallback(btVector3(0.0f, 0.0f, 0.0f), btVector3(0.0f, 0.0f, 0.0f)) {
_me = me;
// the RayResultCallback's group and mask must match MY_AVATAR
m_collisionFilterGroup = BULLET_COLLISION_GROUP_MY_AVATAR;
m_collisionFilterMask = BULLET_COLLISION_MASK_MY_AVATAR;
}
virtual btScalar addSingleResult(btCollisionWorld::LocalRayResult& rayResult,bool normalInWorldSpace) {
if (rayResult.m_collisionObject == _me) {
return 1.0f;
}
return ClosestRayResultCallback::addSingleResult(rayResult, normalInWorldSpace);
}
protected:
btRigidBody* _me;
};
CharacterController::CharacterController() {
_halfHeight = 1.0f;
_enabled = false;
_floorDistance = MAX_FALL_HEIGHT;
_targetVelocity.setValue(0.0f, 0.0f, 0.0f);
_followDesiredBodyTransform.setIdentity();
_followTimeRemaining = 0.0f;
_jumpSpeed = JUMP_SPEED;
_state = State::Hover;
_isPushingUp = false;
_rayHitStartTime = 0;
_takeoffToInAirStartTime = 0;
_jumpButtonDownStartTime = 0;
_jumpButtonDownCount = 0;
_followTime = 0.0f;
_followLinearDisplacement = btVector3(0, 0, 0);
_followAngularDisplacement = btQuaternion::getIdentity();
_hasSupport = false;
_pendingFlags = PENDING_FLAG_UPDATE_SHAPE;
}
CharacterController::~CharacterController() {
if (_rigidBody) {
btCollisionShape* shape = _rigidBody->getCollisionShape();
if (shape) {
delete shape;
}
delete _rigidBody;
_rigidBody = nullptr;
}
}
bool CharacterController::needsRemoval() const {
return ((_pendingFlags & PENDING_FLAG_REMOVE_FROM_SIMULATION) == PENDING_FLAG_REMOVE_FROM_SIMULATION);
}
bool CharacterController::needsAddition() const {
return ((_pendingFlags & PENDING_FLAG_ADD_TO_SIMULATION) == PENDING_FLAG_ADD_TO_SIMULATION);
}
void CharacterController::setDynamicsWorld(btDynamicsWorld* world) {
if (_dynamicsWorld != world) {
if (_dynamicsWorld) {
if (_rigidBody) {
_dynamicsWorld->removeRigidBody(_rigidBody);
_dynamicsWorld->removeAction(this);
}
_dynamicsWorld = nullptr;
}
if (world && _rigidBody) {
_dynamicsWorld = world;
_pendingFlags &= ~PENDING_FLAG_JUMP;
// Before adding the RigidBody to the world we must save its oldGravity to the side
// because adding an object to the world will overwrite it with the default gravity.
btVector3 oldGravity = _rigidBody->getGravity();
_dynamicsWorld->addRigidBody(_rigidBody, BULLET_COLLISION_GROUP_MY_AVATAR, BULLET_COLLISION_MASK_MY_AVATAR);
_dynamicsWorld->addAction(this);
// restore gravity settings
_rigidBody->setGravity(oldGravity);
}
}
if (_dynamicsWorld) {
if (_pendingFlags & PENDING_FLAG_UPDATE_SHAPE) {
// shouldn't fall in here, but if we do make sure both ADD and REMOVE bits are still set
_pendingFlags |= PENDING_FLAG_ADD_TO_SIMULATION | PENDING_FLAG_REMOVE_FROM_SIMULATION;
} else {
_pendingFlags &= ~PENDING_FLAG_ADD_TO_SIMULATION;
}
} else {
_pendingFlags &= ~PENDING_FLAG_REMOVE_FROM_SIMULATION;
}
}
static const float COS_PI_OVER_THREE = cosf(PI / 3.0f);
bool CharacterController::checkForSupport(btCollisionWorld* collisionWorld) const {
int numManifolds = collisionWorld->getDispatcher()->getNumManifolds();
for (int i = 0; i < numManifolds; i++) {
btPersistentManifold* contactManifold = collisionWorld->getDispatcher()->getManifoldByIndexInternal(i);
const btCollisionObject* obA = static_cast<const btCollisionObject*>(contactManifold->getBody0());
const btCollisionObject* obB = static_cast<const btCollisionObject*>(contactManifold->getBody1());
if (obA == _rigidBody || obB == _rigidBody) {
int numContacts = contactManifold->getNumContacts();
for (int j = 0; j < numContacts; j++) {
btManifoldPoint& pt = contactManifold->getContactPoint(j);
// check to see if contact point is touching the bottom sphere of the capsule.
// and the contact normal is not slanted too much.
float contactPointY = (obA == _rigidBody) ? pt.m_localPointA.getY() : pt.m_localPointB.getY();
btVector3 normal = (obA == _rigidBody) ? pt.m_normalWorldOnB : -pt.m_normalWorldOnB;
if (contactPointY < -_halfHeight && normal.dot(_currentUp) > COS_PI_OVER_THREE) {
return true;
}
}
}
}
return false;
}
void CharacterController::preStep(btCollisionWorld* collisionWorld) {
// trace a ray straight down to see if we're standing on the ground
const btTransform& xform = _rigidBody->getWorldTransform();
// rayStart is at center of bottom sphere
btVector3 rayStart = xform.getOrigin() - _halfHeight * _currentUp;
// rayEnd is some short distance outside bottom sphere
const btScalar FLOOR_PROXIMITY_THRESHOLD = 0.3f * _radius;
btScalar rayLength = _radius + FLOOR_PROXIMITY_THRESHOLD;
btVector3 rayEnd = rayStart - rayLength * _currentUp;
// scan down for nearby floor
ClosestNotMe rayCallback(_rigidBody);
rayCallback.m_closestHitFraction = 1.0f;
collisionWorld->rayTest(rayStart, rayEnd, rayCallback);
if (rayCallback.hasHit()) {
_floorDistance = rayLength * rayCallback.m_closestHitFraction - _radius;
}
_hasSupport = checkForSupport(collisionWorld);
}
void CharacterController::playerStep(btCollisionWorld* dynaWorld, btScalar dt) {
const btScalar MIN_SPEED = 0.001f;
btVector3 actualVelocity = _rigidBody->getLinearVelocity() - _parentVelocity;
if (actualVelocity.length() < MIN_SPEED) {
actualVelocity = btVector3(0.0f, 0.0f, 0.0f);
}
btVector3 desiredVelocity = _targetVelocity;
if (desiredVelocity.length() < MIN_SPEED) {
desiredVelocity = btVector3(0.0f, 0.0f, 0.0f);
}
// decompose into horizontal and vertical components.
btVector3 actualVertVelocity = actualVelocity.dot(_currentUp) * _currentUp;
btVector3 actualHorizVelocity = actualVelocity - actualVertVelocity;
btVector3 desiredVertVelocity = desiredVelocity.dot(_currentUp) * _currentUp;
btVector3 desiredHorizVelocity = desiredVelocity - desiredVertVelocity;
btVector3 finalVelocity;
switch (_state) {
case State::Ground:
case State::Takeoff:
{
// horizontal ground control
const btScalar WALK_ACCELERATION_TIMESCALE = 0.1f;
btScalar tau = dt / WALK_ACCELERATION_TIMESCALE;
finalVelocity = tau * desiredHorizVelocity + (1.0f - tau) * actualHorizVelocity + actualVertVelocity;
}
break;
case State::InAir:
{
// horizontal air control
const btScalar IN_AIR_ACCELERATION_TIMESCALE = 2.0f;
btScalar tau = dt / IN_AIR_ACCELERATION_TIMESCALE;
finalVelocity = tau * desiredHorizVelocity + (1.0f - tau) * actualHorizVelocity + actualVertVelocity;
}
break;
case State::Hover:
{
// vertical and horizontal air control
const btScalar FLY_ACCELERATION_TIMESCALE = 0.2f;
btScalar tau = dt / FLY_ACCELERATION_TIMESCALE;
finalVelocity = tau * desiredVelocity + (1.0f - tau) * actualVelocity;
}
break;
}
_rigidBody->setLinearVelocity(finalVelocity + _parentVelocity);
// Dynamicaly compute a follow velocity to move this body toward the _followDesiredBodyTransform.
// Rather then add this velocity to velocity the RigidBody, we explicitly teleport the RigidBody towards its goal.
// This mirrors the computation done in MyAvatar::FollowHelper::postPhysicsUpdate().
const float MINIMUM_TIME_REMAINING = 0.005f;
const float MAX_DISPLACEMENT = 0.5f * _radius;
_followTimeRemaining -= dt;
if (_followTimeRemaining >= MINIMUM_TIME_REMAINING) {
btTransform bodyTransform = _rigidBody->getWorldTransform();
btVector3 startPos = bodyTransform.getOrigin();
btVector3 deltaPos = _followDesiredBodyTransform.getOrigin() - startPos;
btVector3 vel = deltaPos / _followTimeRemaining;
btVector3 linearDisplacement = clampLength(vel * dt, MAX_DISPLACEMENT); // clamp displacement to prevent tunneling.
btVector3 endPos = startPos + linearDisplacement;
btQuaternion startRot = bodyTransform.getRotation();
glm::vec2 currentFacing = getFacingDir2D(bulletToGLM(startRot));
glm::vec2 currentRight(currentFacing.y, -currentFacing.x);
glm::vec2 desiredFacing = getFacingDir2D(bulletToGLM(_followDesiredBodyTransform.getRotation()));
float deltaAngle = acosf(glm::clamp(glm::dot(currentFacing, desiredFacing), -1.0f, 1.0f));
float angularSpeed = deltaAngle / _followTimeRemaining;
float sign = copysignf(1.0f, glm::dot(desiredFacing, currentRight));
btQuaternion angularDisplacement = btQuaternion(btVector3(0.0f, 1.0f, 0.0f), sign * angularSpeed * dt);
btQuaternion endRot = angularDisplacement * startRot;
// in order to accumulate displacement of avatar position, we need to take _shapeLocalOffset into account.
btVector3 shapeLocalOffset = glmToBullet(_shapeLocalOffset);
btVector3 swingDisplacement = rotateVector(endRot, -shapeLocalOffset) - rotateVector(startRot, -shapeLocalOffset);
_followLinearDisplacement = linearDisplacement + swingDisplacement + _followLinearDisplacement;
_followAngularDisplacement = angularDisplacement * _followAngularDisplacement;
_rigidBody->setWorldTransform(btTransform(endRot, endPos));
}
_followTime += dt;
}
void CharacterController::jump() {
_pendingFlags |= PENDING_FLAG_JUMP;
}
bool CharacterController::onGround() const {
const btScalar FLOOR_PROXIMITY_THRESHOLD = 0.3f * _radius;
return _floorDistance < FLOOR_PROXIMITY_THRESHOLD || _hasSupport;
}
#ifdef DEBUG_STATE_CHANGE
static const char* stateToStr(CharacterController::State state) {
switch (state) {
case CharacterController::State::Ground:
return "Ground";
case CharacterController::State::Takeoff:
return "Takeoff";
case CharacterController::State::InAir:
return "InAir";
case CharacterController::State::Hover:
return "Hover";
default:
return "Unknown";
}
}
#endif // #ifdef DEBUG_STATE_CHANGE
#ifdef DEBUG_STATE_CHANGE
void CharacterController::setState(State desiredState, const char* reason) {
#else
void CharacterController::setState(State desiredState) {
#endif
if (!_flyingAllowed && desiredState == State::Hover) {
desiredState = State::InAir;
}
if (desiredState != _state) {
#ifdef DEBUG_STATE_CHANGE
qCDebug(physics) << "CharacterController::setState" << stateToStr(desiredState) << "from" << stateToStr(_state) << "," << reason;
#endif
if (desiredState == State::Hover && _state != State::Hover) {
// hover enter
if (_rigidBody) {
_rigidBody->setGravity(btVector3(0.0f, 0.0f, 0.0f));
}
} else if (_state == State::Hover && desiredState != State::Hover) {
// hover exit
if (_rigidBody) {
_rigidBody->setGravity(DEFAULT_CHARACTER_GRAVITY * _currentUp);
}
}
_state = desiredState;
}
}
void CharacterController::setLocalBoundingBox(const glm::vec3& corner, const glm::vec3& scale) {
_boxScale = scale;
float x = _boxScale.x;
float z = _boxScale.z;
float radius = 0.5f * sqrtf(0.5f * (x * x + z * z));
float halfHeight = 0.5f * _boxScale.y - radius;
float MIN_HALF_HEIGHT = 0.1f;
if (halfHeight < MIN_HALF_HEIGHT) {
halfHeight = MIN_HALF_HEIGHT;
}
// compare dimensions
float radiusDelta = glm::abs(radius - _radius);
float heightDelta = glm::abs(halfHeight - _halfHeight);
if (radiusDelta < FLT_EPSILON && heightDelta < FLT_EPSILON) {
// shape hasn't changed --> nothing to do
} else {
if (_dynamicsWorld) {
// must REMOVE from world prior to shape update
_pendingFlags |= PENDING_FLAG_REMOVE_FROM_SIMULATION;
}
_pendingFlags |= PENDING_FLAG_UPDATE_SHAPE;
// only need to ADD back when we happen to be enabled
if (_enabled) {
_pendingFlags |= PENDING_FLAG_ADD_TO_SIMULATION;
}
}
// it's ok to change offset immediately -- there are no thread safety issues here
_shapeLocalOffset = corner + 0.5f * _boxScale;
}
void CharacterController::setEnabled(bool enabled) {
if (enabled != _enabled) {
if (enabled) {
// Don't bother clearing REMOVE bit since it might be paired with an UPDATE_SHAPE bit.
// Setting the ADD bit here works for all cases so we don't even bother checking other bits.
_pendingFlags |= PENDING_FLAG_ADD_TO_SIMULATION;
} else {
if (_dynamicsWorld) {
_pendingFlags |= PENDING_FLAG_REMOVE_FROM_SIMULATION;
}
_pendingFlags &= ~ PENDING_FLAG_ADD_TO_SIMULATION;
}
SET_STATE(State::Hover, "setEnabled");
_enabled = enabled;
}
}
void CharacterController::updateUpAxis(const glm::quat& rotation) {
btVector3 oldUp = _currentUp;
_currentUp = quatRotate(glmToBullet(rotation), LOCAL_UP_AXIS);
if (_state != State::Hover) {
const btScalar MIN_UP_ERROR = 0.01f;
if (oldUp.distance(_currentUp) > MIN_UP_ERROR) {
_rigidBody->setGravity(DEFAULT_CHARACTER_GRAVITY * _currentUp);
}
}
}
void CharacterController::setPositionAndOrientation(
const glm::vec3& position,
const glm::quat& orientation) {
// TODO: update gravity if up has changed
updateUpAxis(orientation);
btQuaternion bodyOrientation = glmToBullet(orientation);
btVector3 bodyPosition = glmToBullet(position + orientation * _shapeLocalOffset);
_characterBodyTransform = btTransform(bodyOrientation, bodyPosition);
}
void CharacterController::getPositionAndOrientation(glm::vec3& position, glm::quat& rotation) const {
if (_enabled && _rigidBody) {
const btTransform& avatarTransform = _rigidBody->getWorldTransform();
rotation = bulletToGLM(avatarTransform.getRotation());
position = bulletToGLM(avatarTransform.getOrigin()) - rotation * _shapeLocalOffset;
}
}
void CharacterController::setTargetVelocity(const glm::vec3& velocity) {
_targetVelocity = glmToBullet(velocity);
}
void CharacterController::setParentVelocity(const glm::vec3& velocity) {
_parentVelocity = glmToBullet(velocity);
}
void CharacterController::setFollowParameters(const glm::mat4& desiredWorldBodyMatrix, float timeRemaining) {
_followTimeRemaining = timeRemaining;
_followDesiredBodyTransform = glmToBullet(desiredWorldBodyMatrix) * btTransform(btQuaternion::getIdentity(), glmToBullet(_shapeLocalOffset));
}
glm::vec3 CharacterController::getFollowLinearDisplacement() const {
return bulletToGLM(_followLinearDisplacement);
}
glm::quat CharacterController::getFollowAngularDisplacement() const {
return bulletToGLM(_followAngularDisplacement);
}
glm::vec3 CharacterController::getFollowVelocity() const {
if (_followTime > 0.0f) {
return bulletToGLM(_followLinearDisplacement) / _followTime;
} else {
return glm::vec3();
}
}
glm::vec3 CharacterController::getLinearVelocity() const {
glm::vec3 velocity(0.0f);
if (_rigidBody) {
velocity = bulletToGLM(_rigidBody->getLinearVelocity());
}
return velocity;
}
glm::vec3 CharacterController::getVelocityChange() const {
glm::vec3 velocity(0.0f);
if (_rigidBody) {
velocity = bulletToGLM(_rigidBody->getLinearVelocity());
}
return velocity;
}
void CharacterController::preSimulation() {
if (_enabled && _dynamicsWorld) {
quint64 now = usecTimestampNow();
// slam body to where it is supposed to be
_rigidBody->setWorldTransform(_characterBodyTransform);
btVector3 velocity = _rigidBody->getLinearVelocity();
_preSimulationVelocity = velocity;
btVector3 actualVertVelocity = velocity.dot(_currentUp) * _currentUp;
btVector3 actualHorizVelocity = velocity - actualVertVelocity;
// scan for distant floor
// rayStart is at center of bottom sphere
btVector3 rayStart = _characterBodyTransform.getOrigin() - _halfHeight * _currentUp;
// rayEnd is straight down MAX_FALL_HEIGHT
btScalar rayLength = _radius + MAX_FALL_HEIGHT;
btVector3 rayEnd = rayStart - rayLength * _currentUp;
const btScalar JUMP_PROXIMITY_THRESHOLD = 0.1f * _radius;
const quint64 TAKE_OFF_TO_IN_AIR_PERIOD = 250 * MSECS_PER_SECOND;
const btScalar MIN_HOVER_HEIGHT = 2.5f;
const quint64 JUMP_TO_HOVER_PERIOD = 1100 * MSECS_PER_SECOND;
const btScalar MAX_WALKING_SPEED = 2.5f;
const quint64 RAY_HIT_START_PERIOD = 500 * MSECS_PER_SECOND;
ClosestNotMe rayCallback(_rigidBody);
rayCallback.m_closestHitFraction = 1.0f;
_dynamicsWorld->rayTest(rayStart, rayEnd, rayCallback);
bool rayHasHit = rayCallback.hasHit();
if (rayHasHit) {
_rayHitStartTime = now;
_floorDistance = rayLength * rayCallback.m_closestHitFraction - _radius;
} else if ((now - _rayHitStartTime) < RAY_HIT_START_PERIOD) {
rayHasHit = true;
} else {
_floorDistance = FLT_MAX;
}
// record a time stamp when the jump button was first pressed.
if ((_previousFlags & PENDING_FLAG_JUMP) != (_pendingFlags & PENDING_FLAG_JUMP)) {
if (_pendingFlags & PENDING_FLAG_JUMP) {
_jumpButtonDownStartTime = now;
_jumpButtonDownCount++;
}
}
bool jumpButtonHeld = _pendingFlags & PENDING_FLAG_JUMP;
bool flyingFast = _state == State::Hover && actualHorizVelocity.length() > (MAX_WALKING_SPEED * 0.75f);
switch (_state) {
case State::Ground:
if (!rayHasHit && !_hasSupport) {
SET_STATE(State::Hover, "no ground detected");
} else if (_pendingFlags & PENDING_FLAG_JUMP && _jumpButtonDownCount != _takeoffJumpButtonID) {
_takeoffJumpButtonID = _jumpButtonDownCount;
_takeoffToInAirStartTime = now;
SET_STATE(State::Takeoff, "jump pressed");
} else if (rayHasHit && !_hasSupport && _floorDistance > JUMP_PROXIMITY_THRESHOLD) {
SET_STATE(State::InAir, "falling");
}
break;
case State::Takeoff:
if (!rayHasHit && !_hasSupport) {
SET_STATE(State::Hover, "no ground");
} else if ((now - _takeoffToInAirStartTime) > TAKE_OFF_TO_IN_AIR_PERIOD) {
SET_STATE(State::InAir, "takeoff done");
velocity += _jumpSpeed * _currentUp;
_rigidBody->setLinearVelocity(velocity);
}
break;
case State::InAir: {
if ((velocity.dot(_currentUp) <= (JUMP_SPEED / 2.0f)) && ((_floorDistance < JUMP_PROXIMITY_THRESHOLD) || _hasSupport)) {
SET_STATE(State::Ground, "hit ground");
} else if (jumpButtonHeld && (_takeoffJumpButtonID != _jumpButtonDownCount)) {
SET_STATE(State::Hover, "double jump button");
} else if (jumpButtonHeld && (now - _jumpButtonDownStartTime) > JUMP_TO_HOVER_PERIOD) {
SET_STATE(State::Hover, "jump button held");
}
break;
}
case State::Hover:
if ((_floorDistance < MIN_HOVER_HEIGHT) && !jumpButtonHeld && !flyingFast) {
SET_STATE(State::InAir, "near ground");
} else if (((_floorDistance < JUMP_PROXIMITY_THRESHOLD) || _hasSupport) && !flyingFast) {
SET_STATE(State::Ground, "touching ground");
}
break;
}
}
_previousFlags = _pendingFlags;
_pendingFlags &= ~PENDING_FLAG_JUMP;
_followTime = 0.0f;
_followLinearDisplacement = btVector3(0, 0, 0);
_followAngularDisplacement = btQuaternion::getIdentity();
}
void CharacterController::postSimulation() {
// postSimulation() exists for symmetry and just in case we need to do something here later
btVector3 velocity = _rigidBody->getLinearVelocity();
_velocityChange = velocity - _preSimulationVelocity;
}
bool CharacterController::getRigidBodyLocation(glm::vec3& avatarRigidBodyPosition, glm::quat& avatarRigidBodyRotation) {
if (!_rigidBody) {
return false;
}
const btTransform& worldTrans = _rigidBody->getCenterOfMassTransform();
avatarRigidBodyPosition = bulletToGLM(worldTrans.getOrigin()) + ObjectMotionState::getWorldOffset();
avatarRigidBodyRotation = bulletToGLM(worldTrans.getRotation());
return true;
}
void CharacterController::setFlyingAllowed(bool value) {
if (_flyingAllowed != value) {
_flyingAllowed = value;
if (!_flyingAllowed && _state == State::Hover) {
SET_STATE(State::InAir, "flying not allowed");
}
}
}