Feature suggestion: Add "canned" routines

[oskay]

As a possible time-and-buffer saving tool, it might be helpful to add certain canned routines-- tiny macros, so to speak, that might be able to perform some higher level functions within CNCserver.

Typical CNCserver commands are of the form (in pseudocode, not actual API operations):

• pen: Go to (x,y)
• pen: down
• tool: get water
• tool: get color1

These operations typically result in a motor movement, possibly with a subsequence of operations that are performed. For example, "get color1" will perform "pen up, move to position, pen down, wiggle, pen up", using a lookup table to find the required position. However, a considerable time and memory savings might be possible by adding some higher level commands. For example, a drawing that makes 10,000 circles would go much faster if it could send 10,000 command of the form "draw a circle" than if it had to specify the polygon segments that make up each circle.

I propose adding a new category of "canned" routines to handle things of this sort. It could perhaps have the command form PUT /v1/canned/{routinename}. These canned routines should be essentially independent of the tool being used, so that they can be used with any type of tool, in any context-- whether the pen is up or down, and whether it is a brush or a pencil.

Potential examples could include:

• circle(radius) -- draw a circle, centered at the pen's current (x,y) value, with the given radius. A potential challenge is in determining the number of vertices/segments that should be used to draw the circle. It could default (say) to 3 + floor(radius/5), or some other "reasonable" formula. It could also use a minimum/maximum segment length specified some other way, perhaps as part of the tool specification ("typical segment length for canned routines").
• circle(radius, number of vertices) -- to explicitly set the number of vertices
• ellipse(axis1, axis2). Draw an ellipse, centered at the pen's current (x,y) value. The axes are distances (either could be the major or minor axis).
• ellipse(axis1, axis2, angle), where the axes are distances, and the angle is specified between the X axis and the ellipse to be drawn
• rectangle(length1,length2)
• etc (arcs? filled rectangles? spirals?)

This new category may not be the best approach -- I am 100% open to alternate suggestions of better ways to approach this.

[oskay]

Adding the capability for CNCserver to handle these little canned routines might also make for more elegant handling of things like doing the wiggle while getting paint-- it could trace out neat spirals or ellipses in the paint dish instead.