Defining Overall Program Goals

AutoCAD Visual LISP

 
Defining Overall Program Goals
 
 
 

Developing an AutoLISP program begins with an idea for automating some aspect of AutoCAD®. It may be a need to speed up a repetitive drafting function, or to simplify a complex series of operations. For the tutorial, the garden path you want your program to draw is a complex shape with a variable number of components, based on initial input from the user. Here's what it will look like:

Your program must do the following to draw the garden path:

  • Given a start point, an endpoint, and a width, draw a rectilinear boundary. The boundary can be at any 2D orientation. There should be no limit on how large or small it can be.
  • Prompt the user for tile size and tile spacing values. The tiles are simple circles and will fill the boundary but must not overlap or cross the boundary.
  • Place the tiles in alternating rows.

To see how things should work, you can run a completed version of the application that is supplied with AutoCAD.

To run the supplied example

  1. From the AutoCAD Tools menu, choose Load Application.
  2. Select gardenpath.vlx from the Tutorial\VisualLISP directory, and choose Load.
  3. Choose Close.
  4. At the Command prompt, enter gpath.
  5. Respond to the first two prompts by picking a start point and an endpoint in the AutoCAD drawing area.
  6. Enter 2 at the half-width of Path prompt.
  7. Choose OK when prompted by the Garden Path Tile Specifications dialog box.