#ifndef __DMAGNETICFIELDSTEPPER_H__
#define __DMAGNETICFIELDSTEPPER_H__

#include <cuda.h>

#include "GPUMagneticField.cu"

#define qBr2p 0.003  // conversion for converting q*B*r to GeV/c
#define one_sixth 0.16666667

typedef struct{
	float3 pos;
	float3 mom; // normalized
	float q_over_p;
	float mass;
}state_t;

typedef struct{
	int Nsteps;
	int max_steps;
	state_t *steps;
}trajectory_t;


// Host routines
void Swim(float q, float mass, float3 start_pos, float3 start_mom, trajectory_t *&traj);

// Host callable device routines
__global__ void GPU_Swim(float q, float mass, float3 start_pos, float3 start_mom, trajectory_t *traj);


// Device only routines
__device__ float GPU_GetStepSize(state_t &S);
__device__ void GPU_Step(state_t &S);
__device__ void GPU_TestStep(float h, state_t &Sstart, float4 &B, float3 *delta_pos, float3 *new_mom, float4 *Bmid=NULL, float h_frac=0.5);


#endif // __DMAGNETICFIELDSTEPPER_H__