#ifndef _PHYSICS_H
#define _PHYSICS_H

#include "common.h"
#include "itc.h"

typedef struct {
	size_t width, height, depth;
	size_t zstr, ystr, xstr, size; // strides in no. of points (not bytes)
	size_t zstr1, ystr1, xstr1, size1; // same as above but for associated
	                                   // scalar fields
	float spacing; // in meters
} phy_field_info;

typedef struct {
	float *E;
	float *H;
} phy_field_em;

enum {
	PHY_CMD_QUIT,
	PHY_CMD_PAUSE,
	PHY_CMD_RESUME,
	PHY_CMD_STEP,
	PHY_CMD_RESET
};

typedef struct {
	phy_field_info field_info;
	phy_field_em fields[3];
	float *field_eps, *field_mu; //permittivity and permeability
	float time, time_delta;

	// UI stuff
	bool running;
	itc_chan ctl;
	SDL_mutex *rotate_lock;
	int64_t frame_index; // to avoid re-drawing the same fields
	int64_t step_real_time;
} phy_sim;

void phy_sim_destroy(phy_sim *sim);
int phy_sim_create(phy_sim *sim);
void phy_sim_compute_const_fields(phy_sim *sim);
void phy_sim_step(phy_sim *sim);

int phy_thread(phy_sim *sim);

#endif // _PHYSICS_H