//   This is a component for Linuxcnc HAL
//   Copyright 2020 Sam Sokolik <samcoinc@gmail.com>
//
//   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
component polygon "Create a spindle synced motion that carves a polygon using eoffset inputs.  Assumes positive rotation.";

pin in bit enable;
pin in bit enablexslave "enables connecting x postion to radius";
pin in float xpos "connect to the x axis potion in hal";
pin out float xposaten "when componant is enabled - grab current x postion";
pin in unsigned numsides=3 "Number of sides in the polygon";
pin in float inscribedradius=1 "inscribed radius of the polygon";
pin in float cutterdiam "cutter diameter";
pin in float eoffsetscale "scale that eoffset is set to.";
pin in float toolang "angle difference between index and actual tool poition";
pin in float polyang "angle of the polygon";
pin in float spindlepos "Spindle position scaled to 1 per rev";
pin out float spindlerad "Spindle postion in radians";
pin out float polyradius "radious of the polygon at given spindle position";
pin out float xoffset "x offset to send to offset componant";
pin out float yoffset "y offset to send to the offset componant";
pin out signed xeoffset "x eoffset output";
pin out signed yeoffset "y eoffset output";
pin out bit isindex "set index enable only once";
pin io bit indexenable "hooked to index enable of encoder";

function _;
license "GPL";
;;
#include <rtapi_math.h>
#define PI 3.14159265358979323846
float spinang;
float scale;
float spinangoffset;
float polyangoffset;
float radiusslave=0;

    if (!enable) {
        xoffset=0;
        yoffset=0;
        xeoffset=0;
        yeoffset=0;
        isindex = false;
        xposaten = 0;
        return;
    }

// only set index enable once
    if (enable && !isindex) {
	isindex = true;
	indexenable = true;
        if (enablexslave){
            xposaten=xpos;
            }
        return;
    }

// wait for spindle index before actually enabling
    if (enable && isindex && indexenable){
        return;
    }

//convert spinangoffset to ratio.. for adding to spindle pos - plus a couple rotations
//so the spindle position isn't negative
spinangoffset = (toolang/360-polyang/360)+2;
polyangoffset = (polyang/360)*2*PI;

//formual I found is for circumscribed - convert to inscribed - makes more sense.


spinang = ((spindlepos + spinangoffset) - (int)(spindlepos + spinangoffset))*2*PI;

//calculate radius based on if x moves
    if (enablexslave){
        radiusslave=xpos-xposaten;
    }
scale=(inscribedradius-radiusslave)/cos(PI/numsides);
polyradius = ((cos(PI/numsides)/cos((fmod(spinang, (2*PI/numsides))-PI/numsides)))*scale-cutterdiam/2);




//actual offsets applied - could be used for offset componant.
xoffset = cos(spinang+polyangoffset)*polyradius * -1-(radiusslave);
yoffset = sin(spinang+polyangoffset)*polyradius;

//counts for use with eoffset functionality
xeoffset = xoffset / eoffsetscale;
yeoffset = yoffset / eoffsetscale;

spindlerad = spinang;