Creating Turtles
Create and assign turtles.
These commands handle the number of turtles, how they are created, and how to talk to them.
ALLTURTLES
A list of all turtles.
Syntax
ALLTURTLES
Description
ALLTURTLES outputs a list of the names of every turtle that currently defined in Logo. ALLTURTLES is equivalent to the command EVERY “TURTLE.
Example
ALLTURTLES Result: [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]
CTURTLES
Arranges turtles in a circle.
Syntax
CTURTLES number
Description
CTURTLES activates and makes visible the number of turtles specified by its input and arranges them in a circle in the center of the Graphics window. Executing this command resets all turtles to their original shape. See also LTURTLES.
Example
DRAW CTURTLES 16 FD 100
LTURTLES
Arranges turtles in a row.
Syntax
LTURTLES number
Description
LTURTLES activates and makes visible the number of turtles specified by its input and arranges them in a horizontal line along the center of the Graphics window. Executing this command resets all turtles to their original shape. See also CTURTLES.
Example
DRAW LTURTLES 15 FD 100
SETTURTLES
Also: SETT
Creates a range of turtles.
Syntax
SETTURTLES number
SETT number
Description
SETTURTLES defines the total number of turtles available. Their numbers range from 0 to the input of SETTURTLES minus 1. For example, SETTURTLES 16 will create the turtles [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15]. By default, Logo starts with 16 turtles defined and turtle 0 activated.
SETTURTLES creates turtles with the following characteristics:
| Position | Home [0 0] |
| Turtle size | 1 |
| Heading | 0 |
| Line width | 1 |
| Color | 0 (black) |
| Turtle speed | 1 |
| Visibility | FALSE |
| Pattern | 0 |
| Pen state | PENDOWN |
| Font: | Default system font, 9 points |
SETTURTLES accepts any number as input. The actual maximum of turtles depends on the speed of the computer. Therefore, SETTURTLES sets the maximum number of turtles that you can define to 99, although you could use the DECLARE command to create more.
TURTLES reports the number of turtles that have been defined with SETTURTLES. Use the TELL, ASK, EACH, and WHO commands to access multiple turtles.
Example
SETTURTLES 4 TURTLES Result: 4
SETTURTLENAME
Also: SETTNAME
Sets the name of a turtle.
Syntax
SETTURTLENAME :turtle :name
Description
TURTLE name sets the name of the turtle whose object name is supplied as
its first input. It also sets the turtle’s TOOLTIP property.
To get the turtle name, see TURTLENAME.
Example
SETTNAME 0 “JOE TNAME Result: JOE
SETTWINDOW
Attaches a turtle to a Graphics window.
Syntax
SETTWINDOW windowname
Description
SETTWINDOW attaches all active turtles, controls, and bitmaps to a window. Its input is the name of the window in which those objects should appear. Using an empty list as the window name detaches all active objects from their windows, making them invisible.
Use the TWINDOW command to retrieve the name of the window of the first active turtle, control, or bitmap.
Example
SETTWINDOW “GRAPHICS
TURTLENAME
Also: TNAME
Gets the name of the first active turtle.
Syntax
TURTLENAME
Description
TURTLENAME outputs the name of the first active turtle. This is also the value of its NAME property.
To set the turtle name, see SETTURTLENAME.
Example
SETTNAME 0 “JOE TNAME Result: JOE
TURTLENAMES
Also: TNAMES
Outputs a list of all turtle names.
Syntax
TURTLENAMES
Description
TURTLENAMES outputs a list of the names of all turtles.
See also TURTLENAME and SETTURTLENAME.
Example
TURTLENAMES Result: [TURTLE.10 TURTLE.11 TURTLE.12 TURTLE.13 TURTLE.14 TURTLE.15 TURTLE.0 TURTLE.1 TURTLE.2 TURTLE.3 TURTLE.4 TURTLE.5 TURTLE.6 TURTLE.7 TURTLE.8 TURTLE.9]
TURTLES
Reports the number of turtles.
Syntax
TURTLES
Description
The TURTLES command reports the total number of available turtles. Set the number of turtles with SETTURTLES. See also TELLALL, ALLTURTLES, TELLEVEN, and TELLODD.
Example
TURTLES Result: 16
TWINDOW
Outputs the name of the window of the first active turtle.
Syntax
TWINDOW
Description
TWINDOW outputs the name of the window to which the first active turtle,
control, or bitmap is attached. If the turtle is not attached to any
window, its output is the empty list. This command is equivalent to the
command GPROP FIRST
WHO “WINDOW.
Use the SETTWINDOW command to attach a turtle, a control, or a bitmap to a window.
Example
TWINDOW Result: GRAPHICS