Handibot-GCode-To-Geometry

Parse GCode into geometrical lines and curves.

This program is a part of the Shopbot Tools new system but it can be used independently.

This is a work in progress but it should be functional. Maybe the variables will be renamed so be careful if you update for a new version.

List of supported commands:

This software supports the following commands with the following parameters (which can be optional):

G0 X... Y... Z...
G1 X... Y... Z... F...
G2 X... Y... Z... F... I... J... K... or G2 X... Y... Z... F... R...
G3 X... Y... Z... F... I... J... K... or G3 X... Y... Z... F... R...
G17
G18
G19
G20
G21
G90
G91
M02 (this is the only M command parsed because it stops everything, after this command nothing is parsed)

If a parameter is wrong, it will be parsed. It will maybe be skipped.

Example:

G0 X1 Y1  Ook (will act as G0 X1 Y1, will have a warning)
G2 I1 R2      (will be skipped because cannot have R and I, J or K at)
              (the same time. Also, will have an error).

GCode has no real standard, therefore we had to make choices on what is supported or not. This software tries to support all the features Shopbot Tools support.

For each line, everything written after a ( or ; is considered as comment.

Behaviour

By default, the GCode is considered having this setting:

It works on a XY plane (G17)
The values are considered being in inches (G20)
The position is absolute (G90)
The bit is at (0, 0, 0)
The feed rate is set to 0

All the values returned by this program are in inches.

If no feed rate or a negative feed rate has been set for a G1, G2 or G3 command, it is considered that the machine will use a default value for the feed rate. However, if the feed rate is equal to zero, the command will be skipped.

Error and warning system

When parsed, a list of errors is made. When a command has an error, this means this command is skipped. When a command has a warning, this means this command is executed but the behaviour can be different when executed by a real tool.

The error and warning correspond to the behaviour of the Shopbot Tools' machines.

How to use it:

Download the minified version (if there is one) and include the file. Or download all the scripts and include as in the example.html file.
In your code, you just have to use the function GCodeToGeometry.parse(code).

var result = GCodeToGeometry.parse(myGCode);

The parameter must be the GCode in string.

The function will return an object which contains:

gcode : an array of strings, contains the gcode parsed split (each cell contains a line)
size : an object, contains the maximum and minimal coordinate of the bounding box (explained further)
lines : an array of objects, each cell represent a straight or curved line
errorList : an array of errors and warnings
displayInInch : indicate if the values should be displayed in inches (else in millimeters)

All numerical values are in inches.

Object size

It contains the "minimal" point and the "maximum" point of the bounding box of the whole path operation. You can use it to calculate the width, length and width of the operation. The points are in inches. Example:

size = {
    min : { x : 0, y : 0, z : -2 },
    max : { x : 10, y : 5, z : 3 }
}

Line objects

There are two types of lines.

Straight line

This object contains the line number in the GCode where the command is used. The line numbers start by 1. It contains the type of command (G0 or G1) and the feed rate (in inch by minute). It contains the start point, the end point. Example:

line = {
    lineNumber : 12,
    type : "G0",
    feedrate : 2.5,
    start : { x : 5, y : 9, z : 3 },
    end : { x : 3, y : 5, z : 3 }
}

Curved line

This object contains the line number in the GCode where the command is used. The line numbers start by 1. It contains the type of command (G2 or G3) and the feed rate (in inch by minute). It contains an array of cubic Bézier's curves approximating the circular path. Each Bézier's curve object contain four control point. Example:

line = {
    lineNumber : 4,
    type : "G3",
    feedrate : 2.5,
    beziers : [
        {
            p0 : { x : 0     , y : 0     , z : 8.881 }  ,
            p1 : { x : 0.846 , y : 1.677 , z : -3.279 } ,
            p2 : { x : 0.846 , y : 3.333 , z : -6.721 } ,
            p3 : { x : 0     , y : 5     , z : -10 }    ,
        }
    ]
}

Error object

This object contains the information about an error or warning for a command at a line number. Is considered as error when the command is skipped, else as a warning. Example:

error = {
    isSkipped : false
    line : 2
    message : "(warning) No feed rate set (the default is used)."
}

Example

Here is an example of a GCode correctly parsed:

(Illerminaty)
G1 Z-0.333 F66.6
G1 X2
G1 X1 Y1.73205
G1 X0 Y0
G1 Z1
G0 X0.4 Y0.57735
G1 Z-0.333 F66.6
G3 X1.6 R0.8 F91.1
G3 X0.4 R0.8
G1 Z1

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