- User Input
Native Turtle Commands
The languages understood by the Turtle System come with several built in procedures and functions, including those that implement the Turtle Graphics drawing metaphor. A full list of commands is shown in the table below. For convenience, they have been grouped into 10 categories, and divided into three difficulty levels. Only simple commands are shown by default; use the tickboxes below to show intermediate and advanced commands as well.
The Turtle System has 50 predefined colour constants, shown in the table below. Every command that takes a colour argument (e.g. the
colour command, which sets the Turtle's current drawing colour) can be given an RGB value, or one of the predefined colour names below. The compiler will translate this name into the corresponding RGB value. Alternatively, you can also use the corresponding number between 1 and 50, which the Turtle Machine will translate into the RGB value when your program runs.
The Turtle System has 16 fonts for drawing text on the canvas, shown in the table below. The
N.B. Underline and strikethrough are only available on the downloadable system, not the online version. This is because the HTML5 canvas specifications do not support these features.
|Font Family Name||Plain||Italic||Bold||Italic+Bold||Underline||Strikethrough|
cursor command sets which cursor to display when the mouse is over the canvas. Setting it to 0 makes the mouse invisible. Values in the range 1-15 set it to the cursor shown in the table below (move your mouse over each box to preview the cursor). Any other value will reset to the default cursor. Note that the actual cursor displayed depends on your operating system, and may vary from computer to computer.