1 files changed, 113 insertions, 0 deletions
diff --git a/thirdparty/bullet/Bullet3Dynamics/shared/b3IntegrateTransforms.h b/thirdparty/bullet/Bullet3Dynamics/shared/b3IntegrateTransforms.h
new file mode 100644
index 0000000000..e96f90d3f3
--- /dev/null
+++ b/thirdparty/bullet/Bullet3Dynamics/shared/b3IntegrateTransforms.h
@@ -0,0 +1,113 @@
+
+
+#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;
+		
+	}
+	
+}