// Swing Index
//
// swing_index
//
// Swing Index
//
// 
//
// Inputs:    5
// Outputs:   1
// Constants: 0


#include <math.h>
#include "ts.h"


ts_parameter_t const ts_swing_index_p = { .n_inputs = 5, .n_outputs = 1, .n_constants = 0, .params_size = 0 };

uint_t ts_swing_index_offset( ts_constant_t const *c )
{
	( void )c;
	return ( 1 );
}

int ts_swing_index(
	fp_t * const *y, uint_t y_n,
	fp_t const * const *x, uint_t x_n,
	uint_t n, ts_constant_t const *c
)
{
	TS_PROLOGUE( ts_swing_index_p );
	(void)c;
	if (n > 0) y[0][0] = 0;
	for( uint_t i = 1; i < n; ++i )
	{
		fp_t a1 = ts_h( x, i ) - ts_h( x, i - 1 );
		fp_t a2 = ts_l( x, i - 1 ) - ts_l( x, i );
		fp_t a = fmax( a1, a2 );
		fp_t b = ts_c( x, i ) - ts_c( x, i - 1 );
		fp_t ldpl = ts_l( x, i ) - ts_l( x, i - 1 );
		fp_t phmh = ts_h( x, i - 1 ) - ts_h( x, i );
		fp_t c_val = 0;
		if( b < 0 && ldpl > phmh ) c_val = ldpl;
		else if( b >= 0 && phmh > ldpl ) c_val = phmh;
		fp_t hl = ts_h( x, i ) - ts_l( x, i );
		fp_t swing = ( hl != 0 ) ? ( a * 2.0 + b - c_val ) * ts_v( x, i ) / hl : 0;
		y[0][i] = ( i > 1 ? y[0][i - 1] : 0 ) + swing;
	}
	return 0;
}