Difference between revisions of "Activities/Turtle Art/Getting started"
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File:TA-pencolor.png|The 'set color' block affects pen trails, fill and text | File:TA-pencolor.png|The 'set color' block affects pen trails, fill and text | ||
File:TA-pensize.png|'set pen size' block | File:TA-pensize.png|'set pen size' block | ||
| − | File:Penupdown.jpg| | + | File:Penupdown.jpg|'pen up' and 'pen down' |
</gallery> | </gallery> | ||
Revision as of 05:15, 1 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, store n in box1
Use 'start fill' and 'end fill' to draw filled shapes
Boxes, Stacks and the Heap
(aka variables, subroutines and the stack)
named variables:'store in' block
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.
Displaying things
Using 'print' with text
'show' block used for text
'print' and 'show' can display numbers including results of calculations
'print' with text and numbers
'show' an image or video
'show' the camera output
'show' plays sounds as well
Text to speech. Load the Python block with the inbuilt sample code speak.py
Keyboard, mouse and sensor input
Reading the keyboard
Converting the keyboard output to a string
Getting a multi digit number [[1]]
Load the Python block with the sample code push_mouse_event.py to read mouse events
Read the microphone
Read sensors plugged into the microphone socket [2]
Mathematics
logical operations: 'if' block
Make pie charts
