Difference between revisions of "Activities/Turtle Art/Getting started"
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File:TA-if.png|Logical operations: flow control blocks accept >, <, =, and, not, or as input | File:TA-if.png|Logical operations: flow control blocks accept >, <, =, and, not, or as input | ||
File:Pie2.png|Make pie charts [http://wiki.sugarlabs.org/go/File:Turtle_Art_Activity_pie_chart.ta] | File:Pie2.png|Make pie charts [http://wiki.sugarlabs.org/go/File:Turtle_Art_Activity_pie_chart.ta] | ||
| − | File:Functionblock.jpg|Use Python functions, (accepts any of the [http://docs.python.org/library/time.html time] or [http://docs.python.org/library/math.html math] library functions) | + | File:Functionblock.jpg|Use Python functions, (accepts any of the [http://docs.python.org/library/time.html time] or [http://docs.python.org/library/math.html math] library functions) |
| + | File:Coordinates.png|Cartesian and polar coordinate grids | ||
</gallery> | </gallery> | ||
Revision as of 04:45, 2 March 2011
Getting Started
Start by clicking on (or dragging) blocks from the Turtle palette. Use multiple blocks to create drawings; as the turtle moves under your control, colorful lines are drawn.
You add blocks to your program by clicking on or dragging them from the palette to the main area. You can delete a block by dragging it back onto the palette. Click anywhere on a "stack" of blocks to start executing that stack or by clicking in the Rabbit (fast) , Turtle (slow) or Bug (debug) buttons 
on the Project Toolbar.
The basics
Basic turtle graphics: 'forward', 'back', 'arc', and 'right' blocks
The 'set color' block affects pen trails, fill and text
'set pen size' block
'pen up' and 'pen down'
Drawing shapes
Use the 'repeat' block to draw shapes
This can be generalised to n sided polygons, n is stored in 'box 1'
Use 'start fill' and 'end fill' to draw filled shapes
There's no limit
Displaying things
Use 'print' to display in the print window
'show' block used to display at the turtle
'show' an image or video
'show' the camera output
'show' plays sounds as well
'print' and 'show' can display text or numbers including results of calculations
'print' or 'show' mixed text and numbers, using '+'
Text to speech. Load the Python block with the inbuilt sample code speak.py
Boxes, Stacks and the Heap
(aka variables, subroutines and the stack)
Named variables: store a variable in 'box'
Named 'stacks' of blocks can be reused
Collapse a 'stack' of blocks to save space
Store data in the first in last out heap using 'push' and 'pop'
Box names (and stack names) can be boxes, in this case 10 boxes are created. This is a powerful programming feature. A one dimensional array of variables has effectively been created.
Mathematics
Math operators including + - * / mod sqrt
Logical operations: flow control blocks accept >, <, =, and, not, or as input
Make pie charts [1]
Cartesian and polar coordinate grids
