overte-lubosz/libraries/physics/src/CharacterController.cpp
2017-07-24 16:00:13 -07:00

815 lines
32 KiB
C++
Executable file

//
// CharacterControllerInterface.cpp
// libraries/physics/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 "ObjectMotionState.h"
#include "PhysicsHelpers.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) override {
if (rayResult.m_collisionObject == _me) {
return 1.0f;
}
return ClosestRayResultCallback::addSingleResult(rayResult, normalInWorldSpace);
}
protected:
btRigidBody* _me;
};
CharacterController::CharacterMotor::CharacterMotor(const glm::vec3& vel, const glm::quat& rot, float horizTimescale, float vertTimescale) {
velocity = glmToBullet(vel);
rotation = glmToBullet(rot);
hTimescale = horizTimescale;
if (hTimescale < MIN_CHARACTER_MOTOR_TIMESCALE) {
hTimescale = MIN_CHARACTER_MOTOR_TIMESCALE;
}
vTimescale = vertTimescale;
if (vTimescale < 0.0f) {
vTimescale = hTimescale;
} else if (vTimescale < MIN_CHARACTER_MOTOR_TIMESCALE) {
vTimescale = MIN_CHARACTER_MOTOR_TIMESCALE;
}
}
CharacterController::CharacterController() {
_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) {
// remove from old world
if (_dynamicsWorld) {
if (_rigidBody) {
_dynamicsWorld->removeRigidBody(_rigidBody);
_dynamicsWorld->removeAction(this);
}
_dynamicsWorld = nullptr;
}
int16_t collisionGroup = computeCollisionGroup();
if (_rigidBody) {
updateMassProperties();
}
if (world && _rigidBody) {
// add to new world
_dynamicsWorld = world;
_pendingFlags &= ~PENDING_FLAG_JUMP;
_dynamicsWorld->addRigidBody(_rigidBody, collisionGroup, BULLET_COLLISION_MASK_MY_AVATAR);
_dynamicsWorld->addAction(this);
// restore gravity settings because adding an object to the world overwrites its gravity setting
_rigidBody->setGravity(_gravity * _currentUp);
btCollisionShape* shape = _rigidBody->getCollisionShape();
assert(shape && shape->getShapeType() == CONVEX_HULL_SHAPE_PROXYTYPE);
_ghost.setCharacterShape(static_cast<btConvexHullShape*>(shape));
}
_ghost.setCollisionGroupAndMask(collisionGroup, BULLET_COLLISION_MASK_MY_AVATAR & (~ collisionGroup));
_ghost.setCollisionWorld(_dynamicsWorld);
_ghost.setRadiusAndHalfHeight(_radius, _halfHeight);
if (_rigidBody) {
_ghost.setWorldTransform(_rigidBody->getWorldTransform());
}
}
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;
}
}
bool CharacterController::checkForSupport(btCollisionWorld* collisionWorld) {
bool pushing = _targetVelocity.length2() > FLT_EPSILON;
btDispatcher* dispatcher = collisionWorld->getDispatcher();
int numManifolds = dispatcher->getNumManifolds();
bool hasFloor = false;
bool isStuck = false;
btTransform rotation = _rigidBody->getWorldTransform();
rotation.setOrigin(btVector3(0.0f, 0.0f, 0.0f)); // clear translation part
for (int i = 0; i < numManifolds; i++) {
btPersistentManifold* contactManifold = dispatcher->getManifoldByIndexInternal(i);
if (_rigidBody == contactManifold->getBody1() || _rigidBody == contactManifold->getBody0()) {
bool characterIsFirst = _rigidBody == contactManifold->getBody0();
int numContacts = contactManifold->getNumContacts();
int stepContactIndex = -1;
float highestStep = _minStepHeight;
for (int j = 0; j < numContacts; j++) {
// check for "floor"
btManifoldPoint& contact = contactManifold->getContactPoint(j);
btVector3 pointOnCharacter = characterIsFirst ? contact.m_localPointA : contact.m_localPointB; // object-local-frame
btVector3 normal = characterIsFirst ? contact.m_normalWorldOnB : -contact.m_normalWorldOnB; // points toward character
btScalar hitHeight = _halfHeight + _radius + pointOnCharacter.dot(_currentUp);
// If there's non-trivial penetration with a big impulse for several steps, we're probably stuck.
// Note it here in the controller, and let MyAvatar figure out what to do about it.
const float STUCK_PENETRATION = -0.05f; // always negative into the object.
const float STUCK_IMPULSE = 500.0f;
const int STUCK_LIFETIME = 3;
if ((contact.getDistance() < STUCK_PENETRATION) && (contact.getAppliedImpulse() > STUCK_IMPULSE) && (contact.getLifeTime() > STUCK_LIFETIME)) {
isStuck = true; // latch on
}
if (hitHeight < _maxStepHeight && normal.dot(_currentUp) > _minFloorNormalDotUp) {
hasFloor = true;
if (!pushing && isStuck) {
// we're not pushing against anything and we're stuck so we can early exit
// (all we need to know is that there is a floor)
break;
}
}
if (pushing && _targetVelocity.dot(normal) < 0.0f) {
// remember highest step obstacle
if (!_stepUpEnabled || hitHeight > _maxStepHeight) {
// this manifold is invalidated by point that is too high
stepContactIndex = -1;
break;
} else if (hitHeight > highestStep && normal.dot(_targetVelocity) < 0.0f ) {
highestStep = hitHeight;
stepContactIndex = j;
hasFloor = true;
}
}
}
if (stepContactIndex > -1 && highestStep > _stepHeight) {
// remember step info for later
btManifoldPoint& contact = contactManifold->getContactPoint(stepContactIndex);
btVector3 pointOnCharacter = characterIsFirst ? contact.m_localPointA : contact.m_localPointB; // object-local-frame
_stepNormal = characterIsFirst ? contact.m_normalWorldOnB : -contact.m_normalWorldOnB; // points toward character
_stepHeight = highestStep;
_stepPoint = rotation * pointOnCharacter; // rotate into world-frame
}
if (hasFloor && isStuck && !(pushing && _stepUpEnabled)) {
// early exit since all we need to know is that we're on a floor
break;
}
}
}
_isStuck = isStuck;
return hasFloor;
}
void CharacterController::updateAction(btCollisionWorld* collisionWorld, btScalar deltaTime) {
preStep(collisionWorld);
playerStep(collisionWorld, deltaTime);
}
void CharacterController::preStep(btCollisionWorld* collisionWorld) {
// trace a ray straight down to see if we're standing on the ground
const btTransform& transform = _rigidBody->getWorldTransform();
// rayStart is at center of bottom sphere
btVector3 rayStart = transform.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;
}
}
const btScalar MIN_TARGET_SPEED = 0.001f;
const btScalar MIN_TARGET_SPEED_SQUARED = MIN_TARGET_SPEED * MIN_TARGET_SPEED;
void CharacterController::playerStep(btCollisionWorld* collisionWorld, btScalar dt) {
_stepHeight = _minStepHeight; // clears memory of last step obstacle
_hasSupport = checkForSupport(collisionWorld);
btVector3 velocity = _rigidBody->getLinearVelocity() - _parentVelocity;
computeNewVelocity(dt, velocity);
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;
if (_steppingUp) {
float horizontalTargetSpeed = (_targetVelocity - _targetVelocity.dot(_currentUp) * _currentUp).length();
if (horizontalTargetSpeed > FLT_EPSILON) {
// compute a stepUpSpeed that will reach the top of the step in the time it would take
// to move over the _stepPoint at target speed
float horizontalDistance = (_stepPoint - _stepPoint.dot(_currentUp) * _currentUp).length();
float timeToStep = horizontalDistance / horizontalTargetSpeed;
float stepUpSpeed = _stepHeight / timeToStep;
// magically clamp stepUpSpeed to a fraction of horizontalTargetSpeed
// to prevent the avatar from moving unreasonably fast according to human eye
const float MAX_STEP_UP_SPEED = 0.65f * horizontalTargetSpeed;
if (stepUpSpeed > MAX_STEP_UP_SPEED) {
stepUpSpeed = MAX_STEP_UP_SPEED;
}
// add minimum velocity to counteract gravity's displacement during one step
// Note: the 0.5 factor comes from the fact that we really want the
// average velocity contribution from gravity during the step
stepUpSpeed -= 0.5f * _gravity * timeToStep; // remember: _gravity is negative scalar
btScalar vDotUp = velocity.dot(_currentUp);
if (vDotUp < stepUpSpeed) {
// character doesn't have enough upward velocity to cover the step so we help using a "sky hook"
// which uses micro-teleports rather than applying real velocity
// to prevent the avatar from popping up after the step is done
btTransform transform = _rigidBody->getWorldTransform();
transform.setOrigin(transform.getOrigin() + (dt * stepUpSpeed) * _currentUp);
_rigidBody->setWorldTransform(transform);
}
// don't allow the avatar to fall downward when stepping up
// since otherwise this would tend to defeat the step-up behavior
if (vDotUp < 0.0f) {
velocity -= vDotUp * _currentUp;
}
}
}
_rigidBody->setLinearVelocity(velocity + _parentVelocity);
_ghost.setWorldTransform(_rigidBody->getWorldTransform());
}
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
_state = desiredState;
updateGravity();
}
}
void CharacterController::updateGravity() {
int16_t collisionGroup = computeCollisionGroup();
if (_state == State::Hover || collisionGroup == BULLET_COLLISION_GROUP_COLLISIONLESS) {
_gravity = 0.0f;
} else {
const float DEFAULT_CHARACTER_GRAVITY = -5.0f;
_gravity = DEFAULT_CHARACTER_GRAVITY;
}
if (_rigidBody) {
_rigidBody->setGravity(_gravity * _currentUp);
}
}
void CharacterController::setLocalBoundingBox(const glm::vec3& minCorner, const glm::vec3& scale) {
float x = scale.x;
float z = scale.z;
float radius = 0.5f * sqrtf(0.5f * (x * x + z * z));
float halfHeight = 0.5f * scale.y - radius;
float MIN_HALF_HEIGHT = 0.1f;
if (halfHeight < MIN_HALF_HEIGHT) {
halfHeight = MIN_HALF_HEIGHT;
}
// compare dimensions
if (glm::abs(radius - _radius) > FLT_EPSILON || glm::abs(halfHeight - _halfHeight) > FLT_EPSILON) {
_radius = radius;
_halfHeight = halfHeight;
const btScalar DEFAULT_MIN_STEP_HEIGHT_FACTOR = 0.005f;
const btScalar DEFAULT_MAX_STEP_HEIGHT_FACTOR = 0.65f;
_minStepHeight = DEFAULT_MIN_STEP_HEIGHT_FACTOR * (_halfHeight + _radius);
_maxStepHeight = DEFAULT_MAX_STEP_HEIGHT_FACTOR * (_halfHeight + _radius);
if (_dynamicsWorld) {
// must REMOVE from world prior to shape update
_pendingFlags |= PENDING_FLAG_REMOVE_FROM_SIMULATION;
}
_pendingFlags |= PENDING_FLAG_UPDATE_SHAPE;
_pendingFlags |= PENDING_FLAG_ADD_TO_SIMULATION;
}
// it's ok to change offset immediately -- there are no thread safety issues here
_shapeLocalOffset = minCorner + 0.5f * scale;
}
void CharacterController::setCollisionless(bool collisionless) {
if (collisionless != _collisionless) {
_collisionless = collisionless;
_pendingFlags |= PENDING_FLAG_UPDATE_COLLISION_GROUP;
}
}
int16_t CharacterController::computeCollisionGroup() const {
if (_collisionless) {
return _collisionlessAllowed ? BULLET_COLLISION_GROUP_COLLISIONLESS : BULLET_COLLISION_GROUP_MY_AVATAR;
} else {
return BULLET_COLLISION_GROUP_MY_AVATAR;
}
}
void CharacterController::handleChangedCollisionGroup() {
if (_pendingFlags & PENDING_FLAG_UPDATE_COLLISION_GROUP) {
// ATM the easiest way to update collision groups is to remove/re-add the RigidBody
if (_dynamicsWorld) {
_dynamicsWorld->removeRigidBody(_rigidBody);
int16_t collisionGroup = computeCollisionGroup();
_dynamicsWorld->addRigidBody(_rigidBody, collisionGroup, BULLET_COLLISION_MASK_MY_AVATAR);
}
_pendingFlags &= ~PENDING_FLAG_UPDATE_COLLISION_GROUP;
updateGravity();
}
}
void CharacterController::updateUpAxis(const glm::quat& rotation) {
_currentUp = quatRotate(glmToBullet(rotation), LOCAL_UP_AXIS);
if (_rigidBody) {
_rigidBody->setGravity(_gravity * _currentUp);
}
}
void CharacterController::setPositionAndOrientation(
const glm::vec3& position,
const glm::quat& orientation) {
updateUpAxis(orientation);
_rotation = glmToBullet(orientation);
_position = glmToBullet(position + orientation * _shapeLocalOffset);
}
void CharacterController::getPositionAndOrientation(glm::vec3& position, glm::quat& rotation) const {
if (_rigidBody) {
const btTransform& avatarTransform = _rigidBody->getWorldTransform();
rotation = bulletToGLM(avatarTransform.getRotation());
position = bulletToGLM(avatarTransform.getOrigin()) - rotation * _shapeLocalOffset;
}
}
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 {
if (_rigidBody) {
return bulletToGLM(_velocityChange);
}
return glm::vec3(0.0f);
}
void CharacterController::clearMotors() {
_motors.clear();
}
void CharacterController::addMotor(const glm::vec3& velocity, const glm::quat& rotation, float horizTimescale, float vertTimescale) {
_motors.push_back(CharacterController::CharacterMotor(velocity, rotation, horizTimescale, vertTimescale));
}
void CharacterController::applyMotor(int index, btScalar dt, btVector3& worldVelocity, std::vector<btVector3>& velocities, std::vector<btScalar>& weights) {
assert(index < (int)(_motors.size()));
CharacterController::CharacterMotor& motor = _motors[index];
if (motor.hTimescale >= MAX_CHARACTER_MOTOR_TIMESCALE && motor.vTimescale >= MAX_CHARACTER_MOTOR_TIMESCALE) {
// nothing to do
return;
}
// rotate into motor-frame
btVector3 axis = motor.rotation.getAxis();
btScalar angle = motor.rotation.getAngle();
btVector3 velocity = worldVelocity.rotate(axis, -angle);
int16_t collisionGroup = computeCollisionGroup();
if (collisionGroup == BULLET_COLLISION_GROUP_COLLISIONLESS ||
_state == State::Hover || motor.hTimescale == motor.vTimescale) {
// modify velocity
btScalar tau = dt / motor.hTimescale;
if (tau > 1.0f) {
tau = 1.0f;
}
velocity += tau * (motor.velocity - velocity);
// rotate back into world-frame
velocity = velocity.rotate(axis, angle);
_targetVelocity += (tau * motor.velocity).rotate(axis, angle);
// store the velocity and weight
velocities.push_back(velocity);
weights.push_back(tau);
} else {
// compute local UP
btVector3 up = _currentUp.rotate(axis, -angle);
btVector3 motorVelocity = motor.velocity;
// save these non-adjusted components for later
btVector3 vTargetVelocity = motorVelocity.dot(up) * up;
btVector3 hTargetVelocity = motorVelocity - vTargetVelocity;
if (_stepHeight > _minStepHeight && !_steppingUp) {
// there is a step --> compute velocity direction to go over step
btVector3 motorVelocityWF = motorVelocity.rotate(axis, angle);
if (motorVelocityWF.dot(_stepNormal) < 0.0f) {
// the motor pushes against step
_steppingUp = true;
}
}
// split velocity into horizontal and vertical components
btVector3 vVelocity = velocity.dot(up) * up;
btVector3 hVelocity = velocity - vVelocity;
btVector3 vMotorVelocity = motorVelocity.dot(up) * up;
btVector3 hMotorVelocity = motorVelocity - vMotorVelocity;
// modify each component separately
btScalar maxTau = 0.0f;
if (motor.hTimescale < MAX_CHARACTER_MOTOR_TIMESCALE) {
btScalar tau = dt / motor.hTimescale;
if (tau > 1.0f) {
tau = 1.0f;
}
maxTau = tau;
hVelocity += (hMotorVelocity - hVelocity) * tau;
}
if (motor.vTimescale < MAX_CHARACTER_MOTOR_TIMESCALE) {
btScalar tau = dt / motor.vTimescale;
if (tau > 1.0f) {
tau = 1.0f;
}
if (tau > maxTau) {
maxTau = tau;
}
vVelocity += (vMotorVelocity - vVelocity) * tau;
}
// add components back together and rotate into world-frame
velocity = (hVelocity + vVelocity).rotate(axis, angle);
_targetVelocity += maxTau * (hTargetVelocity + vTargetVelocity).rotate(axis, angle);
// store velocity and weights
velocities.push_back(velocity);
weights.push_back(maxTau);
}
}
void CharacterController::computeNewVelocity(btScalar dt, btVector3& velocity) {
if (velocity.length2() < MIN_TARGET_SPEED_SQUARED) {
velocity = btVector3(0.0f, 0.0f, 0.0f);
}
// measure velocity changes and their weights
std::vector<btVector3> velocities;
velocities.reserve(_motors.size());
std::vector<btScalar> weights;
weights.reserve(_motors.size());
_targetVelocity = btVector3(0.0f, 0.0f, 0.0f);
_steppingUp = false;
for (int i = 0; i < (int)_motors.size(); ++i) {
applyMotor(i, dt, velocity, velocities, weights);
}
assert(velocities.size() == weights.size());
// blend velocity changes according to relative weights
btScalar totalWeight = 0.0f;
for (size_t i = 0; i < weights.size(); ++i) {
totalWeight += weights[i];
}
if (totalWeight > 0.0f) {
velocity = btVector3(0.0f, 0.0f, 0.0f);
for (size_t i = 0; i < velocities.size(); ++i) {
velocity += (weights[i] / totalWeight) * velocities[i];
}
_targetVelocity /= totalWeight;
}
if (velocity.length2() < MIN_TARGET_SPEED_SQUARED) {
velocity = btVector3(0.0f, 0.0f, 0.0f);
}
// 'thrust' is applied at the very end
_targetVelocity += dt * _linearAcceleration;
velocity += dt * _linearAcceleration;
// Note the differences between these two variables:
// _targetVelocity = ideal final velocity according to input
// velocity = real final velocity after motors are applied to current velocity
}
void CharacterController::computeNewVelocity(btScalar dt, glm::vec3& velocity) {
btVector3 btVelocity = glmToBullet(velocity);
computeNewVelocity(dt, btVelocity);
velocity = bulletToGLM(btVelocity);
}
void CharacterController::updateState() {
if (!_dynamicsWorld) {
return;
}
const btScalar FLY_TO_GROUND_THRESHOLD = 0.1f * _radius;
const btScalar GROUND_TO_FLY_THRESHOLD = 0.8f * _radius + _halfHeight;
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;
// scan for distant floor
// rayStart is at center of bottom sphere
btVector3 rayStart = _position;
btScalar rayLength = _radius;
int16_t collisionGroup = computeCollisionGroup();
if (collisionGroup == BULLET_COLLISION_GROUP_MY_AVATAR) {
rayLength += MAX_FALL_HEIGHT;
} else {
rayLength += MIN_HOVER_HEIGHT;
}
btVector3 rayEnd = rayStart - rayLength * _currentUp;
ClosestNotMe rayCallback(_rigidBody);
rayCallback.m_closestHitFraction = 1.0f;
_dynamicsWorld->rayTest(rayStart, rayEnd, rayCallback);
bool rayHasHit = rayCallback.hasHit();
quint64 now = usecTimestampNow();
if (rayHasHit) {
_rayHitStartTime = now;
_floorDistance = rayLength * rayCallback.m_closestHitFraction - (_radius + _halfHeight);
} else {
const quint64 RAY_HIT_START_PERIOD = 500 * MSECS_PER_SECOND;
if ((now - _rayHitStartTime) < RAY_HIT_START_PERIOD) {
rayHasHit = true;
} else {
_floorDistance = FLT_MAX;
}
}
// record a time stamp when the jump button was first pressed.
bool jumpButtonHeld = _pendingFlags & PENDING_FLAG_JUMP;
if ((_previousFlags & PENDING_FLAG_JUMP) != (_pendingFlags & PENDING_FLAG_JUMP)) {
if (_pendingFlags & PENDING_FLAG_JUMP) {
_jumpButtonDownStartTime = now;
_jumpButtonDownCount++;
}
}
btVector3 velocity = _preSimulationVelocity;
// disable normal state transitions while collisionless
const btScalar MAX_WALKING_SPEED = 2.65f;
if (collisionGroup == BULLET_COLLISION_GROUP_MY_AVATAR) {
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 > GROUND_TO_FLY_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 < FLY_TO_GROUND_THRESHOLD) || _hasSupport)) {
SET_STATE(State::Ground, "hit ground");
} else {
btVector3 desiredVelocity = _targetVelocity;
if (desiredVelocity.length2() < MIN_TARGET_SPEED_SQUARED) {
desiredVelocity = btVector3(0.0f, 0.0f, 0.0f);
}
bool vertTargetSpeedIsNonZero = desiredVelocity.dot(_currentUp) > MIN_TARGET_SPEED;
if ((jumpButtonHeld || vertTargetSpeedIsNonZero) && (_takeoffJumpButtonID != _jumpButtonDownCount)) {
SET_STATE(State::Hover, "double jump button");
} else if ((jumpButtonHeld || vertTargetSpeedIsNonZero) && (now - _jumpButtonDownStartTime) > JUMP_TO_HOVER_PERIOD) {
SET_STATE(State::Hover, "jump button held");
}
}
break;
}
case State::Hover:
btScalar horizontalSpeed = (velocity - velocity.dot(_currentUp) * _currentUp).length();
bool flyingFast = horizontalSpeed > (MAX_WALKING_SPEED * 0.75f);
if ((_floorDistance < MIN_HOVER_HEIGHT) && !jumpButtonHeld && !flyingFast) {
SET_STATE(State::InAir, "near ground");
} else if (((_floorDistance < FLY_TO_GROUND_THRESHOLD) || _hasSupport) && !flyingFast) {
SET_STATE(State::Ground, "touching ground");
}
break;
}
} else {
// when collisionless: only switch between State::Ground and State::Hover
// and bypass state debugging
if (rayHasHit) {
if (velocity.length() > (MAX_WALKING_SPEED)) {
_state = State::Hover;
} else {
_state = State::Ground;
}
} else {
_state = State::Hover;
}
}
}
void CharacterController::preSimulation() {
if (_rigidBody) {
// slam body transform and remember velocity
_rigidBody->setWorldTransform(btTransform(btTransform(_rotation, _position)));
_preSimulationVelocity = _rigidBody->getLinearVelocity();
updateState();
}
_previousFlags = _pendingFlags;
_pendingFlags &= ~PENDING_FLAG_JUMP;
_followTime = 0.0f;
_followLinearDisplacement = btVector3(0, 0, 0);
_followAngularDisplacement = btQuaternion::getIdentity();
}
void CharacterController::postSimulation() {
if (_rigidBody) {
_velocityChange = _rigidBody->getLinearVelocity() - _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 (value != _flyingAllowed) {
_flyingAllowed = value;
if (!_flyingAllowed && _state == State::Hover) {
SET_STATE(State::InAir, "flying not allowed");
}
}
}
void CharacterController::setCollisionlessAllowed(bool value) {
if (value != _collisionlessAllowed) {
_collisionlessAllowed = value;
_pendingFlags |= PENDING_FLAG_UPDATE_COLLISION_GROUP;
}
}