godot/thirdparty/bullet/Bullet3Dynamics/shared/b3IntegrateTransforms.h
2019-01-07 12:30:35 +01:00

107 lines
3.0 KiB
C++

#include "Bullet3Collision/NarrowPhaseCollision/shared/b3RigidBodyData.h"
inline void integrateSingleTransform(__global b3RigidBodyData_t* bodies, int nodeID, float timeStep, float angularDamping, b3Float4ConstArg gravityAcceleration)
{
if (bodies[nodeID].m_invMass != 0.f)
{
float BT_GPU_ANGULAR_MOTION_THRESHOLD = (0.25f * 3.14159254f);
//angular velocity
{
b3Float4 axis;
//add some hardcoded angular damping
bodies[nodeID].m_angVel.x *= angularDamping;
bodies[nodeID].m_angVel.y *= angularDamping;
bodies[nodeID].m_angVel.z *= angularDamping;
b3Float4 angvel = bodies[nodeID].m_angVel;
float fAngle = b3Sqrt(b3Dot3F4(angvel, angvel));
//limit the angular motion
if (fAngle * timeStep > BT_GPU_ANGULAR_MOTION_THRESHOLD)
{
fAngle = BT_GPU_ANGULAR_MOTION_THRESHOLD / timeStep;
}
if (fAngle < 0.001f)
{
// use Taylor's expansions of sync function
axis = angvel * (0.5f * timeStep - (timeStep * timeStep * timeStep) * 0.020833333333f * fAngle * fAngle);
}
else
{
// sync(fAngle) = sin(c*fAngle)/t
axis = angvel * (b3Sin(0.5f * fAngle * timeStep) / fAngle);
}
b3Quat dorn;
dorn.x = axis.x;
dorn.y = axis.y;
dorn.z = axis.z;
dorn.w = b3Cos(fAngle * timeStep * 0.5f);
b3Quat orn0 = bodies[nodeID].m_quat;
b3Quat predictedOrn = b3QuatMul(dorn, orn0);
predictedOrn = b3QuatNormalized(predictedOrn);
bodies[nodeID].m_quat = predictedOrn;
}
//linear velocity
bodies[nodeID].m_pos += bodies[nodeID].m_linVel * timeStep;
//apply gravity
bodies[nodeID].m_linVel += gravityAcceleration * timeStep;
}
}
inline void b3IntegrateTransform(__global b3RigidBodyData_t* body, float timeStep, float angularDamping, b3Float4ConstArg gravityAcceleration)
{
float BT_GPU_ANGULAR_MOTION_THRESHOLD = (0.25f * 3.14159254f);
if ((body->m_invMass != 0.f))
{
//angular velocity
{
b3Float4 axis;
//add some hardcoded angular damping
body->m_angVel.x *= angularDamping;
body->m_angVel.y *= angularDamping;
body->m_angVel.z *= angularDamping;
b3Float4 angvel = body->m_angVel;
float fAngle = b3Sqrt(b3Dot3F4(angvel, angvel));
//limit the angular motion
if (fAngle * timeStep > BT_GPU_ANGULAR_MOTION_THRESHOLD)
{
fAngle = BT_GPU_ANGULAR_MOTION_THRESHOLD / timeStep;
}
if (fAngle < 0.001f)
{
// use Taylor's expansions of sync function
axis = angvel * (0.5f * timeStep - (timeStep * timeStep * timeStep) * 0.020833333333f * fAngle * fAngle);
}
else
{
// sync(fAngle) = sin(c*fAngle)/t
axis = angvel * (b3Sin(0.5f * fAngle * timeStep) / fAngle);
}
b3Quat dorn;
dorn.x = axis.x;
dorn.y = axis.y;
dorn.z = axis.z;
dorn.w = b3Cos(fAngle * timeStep * 0.5f);
b3Quat orn0 = body->m_quat;
b3Quat predictedOrn = b3QuatMul(dorn, orn0);
predictedOrn = b3QuatNormalized(predictedOrn);
body->m_quat = predictedOrn;
}
//apply gravity
body->m_linVel += gravityAcceleration * timeStep;
//linear velocity
body->m_pos += body->m_linVel * timeStep;
}
}