AutoLISP for Everyone

8/11/2019 AutoLISP for Everyone

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AutoLISP for Everyone!Robert Green

[email protected]

FROM THE TRAILHEAD TO YOUR CAREER SUMMIT.


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AutoCAD user since 1985

Self confessed computer geek

rom an a so



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Lets learn some

(This stuff is fun)



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Some fundamentals

LISP LISt Processor



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It was open source (cheap)

entitles are lists

It made sense at the time (cheap)



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A HUGE base of LISP code exists

LISP does many things very easily as

LISP is weak on dialog controls

View it as an 80/20 language



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Key files and why they matter

LSP

What to mess with



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ACAD.LSP

.

ACADDOC.LSP

.

Help



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They load in a certain order (listed on previousslide)

Some have code in them and some dont

(ACADDOC.LSP and ACAD.LSP dont as anexample)

They reside in the SUPPORT folder



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You create your own ACADDOC.LSP so youcant really mess it up

It loads with every new drawing

away

If you mess up too bad, just delete!



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Syntax Basics

Lists and Arguments

Variables

Accessing the

Special characters



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+

o Here the + is a FUNCTION and the two numbersare ARGUMENTS

(command line 0,0 1,1 )

o Here COMMAND is the function, all others areARGUMENTS



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Some RulesFor every ( there is an equal and opposite ) Newton

Like this: (setq A 3.0)

Not like this: (setq A 3.0)) or (setq A 3.0

Same oes for uote marks!

Like this: (setq name Robert Green)

Not like this: (setq name Robert Green)se q name o er reen

When formatting numbers always avoid invalid dotted

pa rsLike this: (setq A 0.5)

Not like this: (setq A .5)



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Function Lists Embedded ListsStandard AutoLISP Result

8 + 2.3 (+ 8 2.3) 10.3

. . . . .

5 4 (/ 5 4) 1

(8 + 4) * 3 (* (+ 8 4) 3) 36

(3.0 * 5.0) 4.0 (/ (* 3.0 5.0) 4.0) 3.75



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How would you work normally?

o Type in LINE to start the line command

o

o Click POINT for second point location

PAUSE waits for the user


e s equa o ng e ey


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Whats Going On Here?

(command viewres y 5000)

-

(command -linetype set BYLAYER )

.

(command viewres y pause)

Thats not so bad intuitive actually



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Variables and Data Types

Real

String

ser npu



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Variables and data types

SETQ (SET eQual)

.

(setq VALUE 1) integer number

(setq VALUE 1.0) - ?

(setq VIEWRES_VALUE 5000) - ?



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Variables and Commands

(setq VIEWRES_VALUE 5000)

_

o What would happen in this case?

_

o (command viewres y viewres_value)

Variable TYPES and how they interact with



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User functions

Speed for the user

A win-win scenario

e s pu every ng

weve learned into action

to build some functions.



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User Function Examples

(command .zoom a)

)



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User Function Examples

(defun C:VR ()

command viewres 5000

)

(defun C:BL ()

-


)



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Fillet Zero Function

Fillet Zero

(setvar filletrad 0.0)

.

(princ)



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Improved Fillet Zero

(defun c:fz ()

_

(setvar filletrad 0.0)

.

(setvar filletrad old_filletrad)

pr nc

)



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Auto Purge Function

Auto Purge

(command -purge a * n .qsave)

)



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More Bits and Bytes

Undefine

Dot form

Alerts



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Undefining

(command .undefine LINE)

Dont want them messing with a command? Justundefine it

Now ou can SUBTRACT from the

AutoCAD Command set in yourACADDOC.LSP file.



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The DOT form

Invoke commands like this: .LINE

This allows you to invoke a command whether it hasbeen undefined or not!

This is our little secret right ...



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Redefining

(command .redefine LINE)

Want to be sure that a command is active?

Now ou can UNSUBTRACT from the

AutoCAD Command set with ease.



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Undefining revisted

What if your users find out about REDEFINE and start

REDEFINING your UNDEFINES?

Just undefine the redefine like this:

command .undefine REDEFINE

Thatll show em



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Redefining

You can undefine a command and redefine it like this:

(defun C:TORUS ()

(princ)

Now you do whatever you want!



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Command echo (CMDECHO)

Run in STEALTH mode like this:

defun C:BL

(setvar cmdecho 0)command -color BYLAYER


setvar cmdecho 1

(princ)



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Wrapping up: Resources

CADDEPOT.com

.

Cadalyst Magazine

e ar en a

Developers Help



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Thank ou for attendin !Any questions?

Email me: [email protected]

Be sure to check out the video segments Ill post at my

-


Documents

AutoLISP for Everyone