overte-HifiExperiments/libraries/physics/src/DynamicCharacterController.cpp
2015-04-06 16:19:14 -07:00

309 lines
11 KiB
C++

#include <BulletCollision/CollisionShapes/btMultiSphereShape.h>
#include <BulletDynamics/Dynamics/btRigidBody.h>
#include <BulletCollision/CollisionDispatch/btCollisionWorld.h>
#include <LinearMath/btDefaultMotionState.h>
#include "BulletUtil.h"
#include "DynamicCharacterController.h"
const btVector3 LOCAL_UP_AXIS(0.0f, 1.0f, 0.0f);
const float DEFAULT_GRAVITY = 5.0f;
const float TERMINAL_VELOCITY = 55.0f;
const float JUMP_SPEED = 3.5f;
const uint32_t PENDING_FLAG_ADD_TO_SIMULATION = 1U << 0;
const uint32_t PENDING_FLAG_REMOVE_FROM_SIMULATION = 1U << 1;
const uint32_t PENDING_FLAG_UPDATE_SHAPE = 1U << 2;
const uint32_t PENDING_FLAG_JUMP = 1U << 3;
DynamicCharacterController::DynamicCharacterController(AvatarData* avatarData) {
_rayLambda[0] = 1.0f;
_rayLambda[1] = 1.0f;
_halfHeight = 1.0f;
_shape = NULL;
_rigidBody = NULL;
assert(avatarData);
_avatarData = avatarData;
_enabled = false;
_walkVelocity.setValue(0.0f,0.0f,0.0f);
_jumpSpeed = JUMP_SPEED;
_isOnGround = false;
_isJumping = false;
_isHovering = true;
_pendingFlags = PENDING_FLAG_UPDATE_SHAPE;
updateShapeIfNecessary();
}
DynamicCharacterController::~DynamicCharacterController() {
}
// virtual
void DynamicCharacterController::setWalkDirection(const btVector3& walkDirection) {
_walkVelocity = walkDirection;
}
void DynamicCharacterController::preStep(btCollisionWorld* collisionWorld) {
const btTransform& xform = _rigidBody->getCenterOfMassTransform();
btVector3 down = -xform.getBasis()[1];
btVector3 forward = xform.getBasis()[2];
down.normalize();
forward.normalize();
_raySource[0] = xform.getOrigin();
_raySource[1] = xform.getOrigin();
_rayTarget[0] = _raySource[0] + down * _halfHeight * btScalar(1.1f);
_rayTarget[1] = _raySource[1] + forward * _halfHeight * btScalar(1.1f);
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;
}
virtual btScalar addSingleResult(btCollisionWorld::LocalRayResult& rayResult,bool normalInWorldSpace) {
if (rayResult.m_collisionObject == _me)
return 1.0f;
return ClosestRayResultCallback::addSingleResult(rayResult, normalInWorldSpace
);
}
protected:
btRigidBody* _me;
};
ClosestNotMe rayCallback(_rigidBody);
int i = 0;
for (i = 0; i < 2; i++) {
rayCallback.m_closestHitFraction = 1.0f;
collisionWorld->rayTest(_raySource[i], _rayTarget[i], rayCallback);
if (rayCallback.hasHit()) {
_rayLambda[i] = rayCallback.m_closestHitFraction;
} else {
_rayLambda[i] = 1.0f;
}
}
}
void DynamicCharacterController::playerStep(btCollisionWorld* dynaWorld,btScalar dt) {
btVector3 currentVelocity = _rigidBody->getLinearVelocity();
btScalar currentSpeed = currentVelocity.length();
btVector3 desiredVelocity = _walkVelocity;
btScalar desiredSpeed = desiredVelocity.length();
const btScalar MIN_SPEED = 0.001f;
if (desiredSpeed < MIN_SPEED) {
if (currentSpeed < MIN_SPEED) {
_rigidBody->setLinearVelocity(btVector3(0.0f, 0.0f, 0.0f));
} else {
const btScalar BRAKING_TIMESCALE = 0.2f;
btScalar tau = dt / BRAKING_TIMESCALE;
_rigidBody->setLinearVelocity((1.0f - tau) * currentVelocity);
}
} else {
const btScalar WALKING_TIMESCALE = 0.5f;
btScalar tau = dt / WALKING_TIMESCALE;
if (onGround()) {
// subtract vertical component
desiredVelocity = desiredVelocity - desiredVelocity.dot(_currentUp) * _currentUp;
}
_rigidBody->setLinearVelocity(currentVelocity - tau * (currentVelocity - desiredVelocity));
}
}
bool DynamicCharacterController::canJump() const {
return onGround();
}
void DynamicCharacterController::jump() {
/*
if (!canJump()) {
return;
}
btTransform xform = _rigidBody->getCenterOfMassTransform();
btVector3 up = xform.getBasis()[1];
up.normalize();
btScalar magnitude = (btScalar(1.0)/_rigidBody->getInvMass()) * btScalar(8.0);
_rigidBody->applyCentralImpulse(up * magnitude);
*/
}
bool DynamicCharacterController::onGround() const {
return _rayLambda[0] < btScalar(1.0);
}
void DynamicCharacterController::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;
}
bool DynamicCharacterController::needsRemoval() const {
return (bool)(_pendingFlags & PENDING_FLAG_REMOVE_FROM_SIMULATION);
}
bool DynamicCharacterController::needsAddition() const {
return (bool)(_pendingFlags & PENDING_FLAG_ADD_TO_SIMULATION);
}
void DynamicCharacterController::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;
_isHovering = true;
} else {
if (_dynamicsWorld) {
_pendingFlags |= PENDING_FLAG_REMOVE_FROM_SIMULATION;
}
_pendingFlags &= ~ PENDING_FLAG_ADD_TO_SIMULATION;
_isOnGround = false;
}
_enabled = enabled;
}
}
void DynamicCharacterController::setDynamicsWorld(btDynamicsWorld* world) {
if (_dynamicsWorld != world) {
if (_dynamicsWorld) {
if (_rigidBody) {
_dynamicsWorld->removeRigidBody(_rigidBody);
_dynamicsWorld->removeAction(this);
}
_dynamicsWorld = NULL;
}
if (world && _rigidBody) {
_dynamicsWorld = world;
_pendingFlags &= ~ PENDING_FLAG_JUMP;
_dynamicsWorld->addRigidBody(_rigidBody);
_dynamicsWorld->addAction(this);
//reset(_dynamicsWorld);
}
}
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;
}
}
void DynamicCharacterController::updateShapeIfNecessary() {
if (_pendingFlags & PENDING_FLAG_UPDATE_SHAPE) {
// make sure there is NO pending removal from simulation at this point
// (don't want to delete _rigidBody out from under the simulation)
assert(!(_pendingFlags & PENDING_FLAG_REMOVE_FROM_SIMULATION));
_pendingFlags &= ~ PENDING_FLAG_UPDATE_SHAPE;
// delete shape and RigidBody
delete _rigidBody;
_rigidBody = NULL;
delete _shape;
_shape = NULL;
// compute new dimensions from avatar's bounding box
float x = _boxScale.x;
float z = _boxScale.z;
_radius = 0.5f * sqrtf(0.5f * (x * x + z * z));
_halfHeight = 0.5f * _boxScale.y - _radius;
float MIN_HALF_HEIGHT = 0.1f;
if (_halfHeight < MIN_HALF_HEIGHT) {
_halfHeight = MIN_HALF_HEIGHT;
}
// NOTE: _shapeLocalOffset is already computed
if (_radius > 0.0f) {
// create new shape
_shape = new btCapsuleShape(_radius, 2.0f * _halfHeight);
// create new body
float mass = 1.0f;
btVector3 inertia(1.0f, 1.0f, 1.0f);
_rigidBody = new btRigidBody(mass, NULL, _shape, inertia);
_rigidBody->setSleepingThresholds (0.0f, 0.0f);
_rigidBody->setAngularFactor (0.0f);
_rigidBody->setWorldTransform(btTransform(glmToBullet(_avatarData->getOrientation()),
glmToBullet(_avatarData->getPosition())));
//_rigidBody->setCollisionFlags(btCollisionObject::CF_CHARACTER_OBJECT);
} else {
// TODO: handle this failure case
}
}
}
void DynamicCharacterController::preSimulation(btScalar timeStep) {
if (_enabled && _dynamicsWorld) {
glm::quat rotation = _avatarData->getOrientation();
_currentUp = quatRotate(glmToBullet(rotation), LOCAL_UP_AXIS);
glm::vec3 position = _avatarData->getPosition() + rotation * _shapeLocalOffset;
// TODO: get intended WALK velocity from _avatarData, not its actual velocity
btVector3 walkVelocity = glmToBullet(_avatarData->getVelocity());
_rigidBody->setWorldTransform(btTransform(glmToBullet(rotation), glmToBullet(position)));
_rigidBody->setLinearVelocity(walkVelocity);
if (_pendingFlags & PENDING_FLAG_JUMP) {
_pendingFlags &= ~ PENDING_FLAG_JUMP;
if (canJump()) {
// TODO: make jump work
//_verticalVelocity = _jumpSpeed;
_isJumping = true;
}
}
// the rotation is determined by AvatarData
btTransform xform = _rigidBody->getCenterOfMassTransform();
xform.setRotation(glmToBullet(rotation));
_rigidBody->setCenterOfMassTransform(xform);
}
}
void DynamicCharacterController::postSimulation() {
if (_enabled && _rigidBody) {
const btTransform& avatarTransform = _rigidBody->getCenterOfMassTransform();
glm::quat rotation = bulletToGLM(avatarTransform.getRotation());
glm::vec3 position = bulletToGLM(avatarTransform.getOrigin());
_avatarData->setOrientation(rotation);
_avatarData->setPosition(position - rotation * _shapeLocalOffset);
}
}