//   This is a component for EMC2 HAL
//   Copyright 2007 John Kasunich <jmkasunich AT sourceforge DOT net>
//
//   This program is free software; you can redistribute it and/or modify
//   it under the terms of the GNU General Public License as published by
//   the Free Software Foundation; either version 2 of the License, or
//   (at your option) any later version.
//
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU General Public License for more details.
//
//   You should have received a copy of the GNU General Public License
//   along with this program; if not, write to the Free Software
//   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

component knob2float "Convert counts (probably from an encoder) to a float value";

pin in s32 counts "Counts";
pin in bit enable "When TRUE, output is controlled by count, when FALSE, output is fixed";
pin in float scale "Amount of output change per count";
pin out float out "Output value";

param rw float max_out=1.0 "Maximum output value, further increases in count will be ignored";
param rw float min_out=0.0 "Minimum output value, further decreases in count will be ignored";

option data knob2float_data;

function _;
license "GPL";
;;

typedef struct {
    long old_counts;
    double old_out;
} knob2float_data;

FUNCTION(_) {
    long delta_counts;
    double tmp_out;

    if ( min_out > max_out ) {
	min_out = max_out;
    }
    delta_counts = counts - data.old_counts;
    if ( enable ) {
	tmp_out = data.old_out + delta_counts * scale;
	if ( tmp_out > max_out ) {
	    data.old_out = max_out;
	} else if ( tmp_out < min_out ) {
	    data.old_out = min_out;
	} else {
	    data.old_out = tmp_out;
	}
    }
    out = data.old_out;
    data.old_counts += delta_counts;
}