Tutorial: Designing a Garden Path (VBA/ActiveX)

This tutorial demonstrates the fundamentals of using ActiveX and Visual Basic for Applications (VBA), and create a macro for use in the AutoCAD drawing environment.

Audience

The tutorial is oriented toward landscape architectures, but the concepts in the tutorial are relevant to any industry.

Prerequisites

  1. Checking Your Environment
    The AutoCAD VBA integrated development environment (VBA IDE) needs to be installed to create and execute macros.
  2. Defining the Goal of the Garden Path
    The goal of this tutorial is to develop a new macro named Gardenpath that draws a garden path and fills the path with circular concrete tiles.
  3. Writing the Utility Functions
    When writing a program, it is beneficial to write small logical subroutines that can be repurposed for other programs. The Gardenpath macro is defined using a series of primary and secondary (utility) functions and subroutines.
  4. Declaring Global Variables
    The subroutines of the Gardenpath macro utilize several global variables. A global variable can be used to exchange a value between functions or store a value while the project is loaded in memory.
  5. Defining the Command Prompt Interaction and Calculating Values
    The gpuser subroutine prompts the user for information necessary to draw a garden path.
  6. Drawing the Outline of the Garden Path
    The outline of the path can be drawn using the location and half width of the path acquired with the gpuser subroutine.
  7. Drawing the Tiles within the Garden Path
    The drawtiles and drow subroutines are used to draw and calculate the circular tiles for the path.
  8. Putting it All Together
    Writing small subroutines allows for them to be used as building blocks to define a macro which the user can execute.
  9. Executing the GardenPath Macro
    A Public subroutine, also known as a macro, can be executed from the AutoCAD user interface.
  10. Stepping Through Code
    Code in a subroutine or function can be stepped through during execution to help identify problems and evaluate branching within the code.
  11. Creating and Adding Controls to a Dialog Box
    A dialog box can be used to get input from a user and then use the values received for the subroutines defined in the project.
  12. Modifying the Properties of the Controls and User Form
    Properties define the behavior and appearance of a control or user form.
  13. Handling Control and User Form Events
    Events are triggered as a result of the user interacting with controls on a user form along with when predefined actions occur to the user form.

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