blender/extern/bullet/LinearMath/SimdTransformUtil.h
Erwin Coumans af9573e9ea Synchronized Bullet physics to latest version.
- Changed license from MIT to ZLib.
- Added 3D Sweep and Prune contribution
- More stable native constraint solver

Sorry for any inconvenience caused by this checkin.
All Blender buildsystems require update: added files and moved files.
2006-03-27 06:37:30 +00:00

137 lines
4.0 KiB
C++

/*
Copyright (c) 2003-2006 Gino van den Bergen / Erwin Coumans http://continuousphysics.com/Bullet/
This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#ifndef SIMD_TRANSFORM_UTIL_H
#define SIMD_TRANSFORM_UTIL_H
#include "SimdTransform.h"
#define ANGULAR_MOTION_TRESHOLD 0.5f*SIMD_HALF_PI
#define SIMDSQRT12 SimdScalar(0.7071067811865475244008443621048490)
#define SimdRecipSqrt(x) ((float)(1.0f/SimdSqrt(float(x)))) /* reciprocal square root */
inline void SimdPlaneSpace1 (const SimdVector3& n, SimdVector3& p, SimdVector3& q)
{
if (SimdFabs(n[2]) > SIMDSQRT12) {
// choose p in y-z plane
SimdScalar a = n[1]*n[1] + n[2]*n[2];
SimdScalar k = SimdRecipSqrt (a);
p[0] = 0;
p[1] = -n[2]*k;
p[2] = n[1]*k;
// set q = n x p
q[0] = a*k;
q[1] = -n[0]*p[2];
q[2] = n[0]*p[1];
}
else {
// choose p in x-y plane
SimdScalar a = n[0]*n[0] + n[1]*n[1];
SimdScalar k = SimdRecipSqrt (a);
p[0] = -n[1]*k;
p[1] = n[0]*k;
p[2] = 0;
// set q = n x p
q[0] = -n[2]*p[1];
q[1] = n[2]*p[0];
q[2] = a*k;
}
}
/// Utils related to temporal transforms
class SimdTransformUtil
{
public:
static void IntegrateTransform(const SimdTransform& curTrans,const SimdVector3& linvel,const SimdVector3& angvel,SimdScalar timeStep,SimdTransform& predictedTransform)
{
predictedTransform.setOrigin(curTrans.getOrigin() + linvel * timeStep);
// #define QUATERNION_DERIVATIVE
#ifdef QUATERNION_DERIVATIVE
SimdQuaternion orn = curTrans.getRotation();
orn += (angvel * orn) * (timeStep * 0.5f);
orn.normalize();
#else
//exponential map
SimdVector3 axis;
SimdScalar fAngle = angvel.length();
//limit the angular motion
if (fAngle*timeStep > ANGULAR_MOTION_TRESHOLD)
{
fAngle = ANGULAR_MOTION_TRESHOLD / 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*( SimdSin(0.5f*fAngle*timeStep)/fAngle );
}
SimdQuaternion dorn (axis.x(),axis.y(),axis.z(),SimdCos( fAngle*timeStep*0.5f ));
SimdQuaternion orn0 = curTrans.getRotation();
SimdQuaternion predictedOrn = dorn * orn0;
#endif
predictedTransform.setRotation(predictedOrn);
}
static void CalculateVelocity(const SimdTransform& transform0,const SimdTransform& transform1,SimdScalar timeStep,SimdVector3& linVel,SimdVector3& angVel)
{
linVel = (transform1.getOrigin() - transform0.getOrigin()) / timeStep;
#ifdef USE_QUATERNION_DIFF
SimdQuaternion orn0 = transform0.getRotation();
SimdQuaternion orn1a = transform1.getRotation();
SimdQuaternion orn1 = orn0.farthest(orn1a);
SimdQuaternion dorn = orn1 * orn0.inverse();
#else
SimdMatrix3x3 dmat = transform1.getBasis() * transform0.getBasis().inverse();
SimdQuaternion dorn;
dmat.getRotation(dorn);
#endif//USE_QUATERNION_DIFF
SimdVector3 axis;
SimdScalar angle;
angle = dorn.getAngle();
axis = SimdVector3(dorn.x(),dorn.y(),dorn.z());
axis[3] = 0.f;
//check for axis length
SimdScalar len = axis.length2();
if (len < 0.001f)
axis = SimdVector3(1.f,0.f,0.f);
else
axis /= SimdSqrt(len);
angVel = axis * angle / timeStep;
}
};
#endif //SIMD_TRANSFORM_UTIL_H