ACSLogo Features

The Logo language

ACSLogo is an implementation of the Logo language, used in teaching programming techniques. The purpose of a Logo program is to move a 'turtle' around a canvas using commands:

forward 100 right 45 forward 100

Logo is a full-featured programming language including:

• arithmetical expressions
• conditional and repetitive constructs
• drawing functions
• trigonometric functions
• list-processing functions
• string-processing functions
• procedures

Quartz Graphics

ACSLogo uses the Quartz graphics system underlying Mac OSX. It therefore supports these advanced graphic features:

• anti-aliasing of lines and fonts
• fonts of any available face, size, and colour
• a turtle with variable size, transparency, and shadow
• setting the current colour to any RGB value and opacity

ACSLogo as Word Processor

ACSLogo uses the text-processing features built into OSX, allowing font style, weight, size, colour and alignment to be changed in the main editor window:

The whole document, or selected text, can be printed.

ACSLogo as Calculator

You can type an arbitrary arithmetic expression into the main editor window and ACSLogo will calculate the result for you.

Exporting Bitmap Graphics (TIFFs)

The result of your drawing commands can be exported as a bitmap. This is in the standard TIFF format which can be imported into hundreds of graphic programs.

Exporting Vector Graphics

As well as bitmap graphics, graphics can be exported in vector form — these graphics are resolution independent: they can be magnified without loss of quality. Three types of vector graphics can be exported:

• Scalable Vector Graphics. SVGs are a new web standard - they are XML-based, so can be edited with a text-editor. Some of the more recent versions of illustration programs (such as Adobe illustrator 10) should be able to import and edit them. Shadows are preserved. For more information on SVGs, see Adobe.com
• EPS. EPS files can be imported into most decent illustration programs.
• PDF. PDFs can be viewed in Adobe Reader.

Exporting Movies

Quicktime movies can be created by Snaping the graphics window at selected points. For examples, see Movie examples.

Speech

You can use the Say command to speak using the OS X speech synthesizer.

Music

Use the Play command to play sequences of notes and chords. Different synthesized instruments are available.

Alan Smith
Norwich, UK
March 2005