g-code defaults to mm not meters, allow offset

[JamesNewton]

g-code generally defaults to millimeters, but Dexter takes in meters. A default value for a scale factor of 0.001 corrects this issue and allows scaling to be changed. Also include an offset in x, y, and z to help it work in a better area.

[JamesNewton]

The following will run in the current DDE4, backfill this change, and includes simple g-code to demo the functionality by having the arm draw a square on the floor.

Gcode.move_it = function(){
        let y_pos = this.state.Y
        y_pos += this.state.Y_offset
        if(y_pos === 0) { y_pos = 1e-10 }//to avoid singularity
        let xyz = [ ( this.state.X + this.offset[0] ) * this.scale 
        	, ( y_pos + this.offset[1] ) * this.scale
            , ( this.state.Z + this.offset[2] ) * this.scale
            ]
        //debugger
        return [ function() { Gcode.extrude()},
                 Dexter.move_to(xyz)
               ]
    }
Gcode.scale = .001 //units are mm, convert to meters
Gcode.offset = [0,100,80] //xyz offset in mm

var gcode = `
; G-Code to print a test object coded by hand
G21 ; set units to millimeters
G28 ; home all axes (if no X,Y,Z, all are assumed)
G0 Z5 ; quickly lift nozzle 5mm
M109 S195 ; wait for temperature to be reached
G90 ; use absolute coordinates
G92 E0 ; Set current extruder position as home
M82 ; use absolute distances for extrusion
G0 Z0.4 ; drop to first layer height
G0 X100 Y100 ; move to starting point @10,10
G1 X100 Y200 F540 E0.2 ; slow extrude to next point.
G1 X200 Y200 E0.4 ; slow extrude to next point.
G1 X200 Y100 E0.6 ; slow extrude to next point.
G1 X100 Y100 E0.8 ; slow extrude to starting point.

`
gcode = gcode.replace(/;[^\n]+[\n]/gm, '\n'); //remove comment lines (starting with ';')
gcode = gcode.replace(/M117 [^\n]+[\n]/gm, '\n'); //remove LCD update lines

new Job({
    name: "my_job_gcode",
    do_list: [
        Dexter.run_gcode({gcode:gcode})
    ]
})