path: root/tde-i18n-en_GB/docs/tdeedu/kturtle/getting-started.docbook

<chapter id="getting-started">
<title
>Getting Started</title>
<para
>When you start &kturtle; you will see something like this: <screenshot
> <screeninfo
>Here is a screenshot of &kturtle; when you start it for the first time</screeninfo
> <mediaobject
> <imageobject
> <imagedata fileref="mainwindow.png" format="PNG"/> </imageobject
> <textobject
> <phrase
>&kturtle; Main window</phrase
> </textobject
> </mediaobject
> </screenshot
> In this Getting Started guide we assume that the language of the &logo; commands is English. You can change this language in <menuchoice
><guimenu
>Settings</guimenu
><guimenuitem
>Configure &kturtle;...</guimenuitem
></menuchoice
> in the <guilabel
>Language</guilabel
> section. Be aware that the language you set here for &kturtle; is the one you use to type the &logo; commands.</para>

<sect1 id="first-steps">
<title
>First steps with &logo;: meet the Turtle!</title>
<para
>You must have noticed the turtle is in the middle of the canvas: you are just about to learn how to control it using commands in the code editor.</para>

<sect2 id="the-turtle-moves">
<title
>The Turtle Moves</title>
<para
>Let us start by getting the turtle moving. Our turtle can do 3 types of moves, (1) it can go forwards and backwards, (2) it can turn left and right and (3) it can go directly to a position on the screen. Try this for example:</para>
<para>
<screen
>forward 90
turnleft 90 
</screen>
Type or copy-paste the code to the code editor and execute it (using <link linkend="file-execute"
><menuchoice
><guimenu
>File</guimenu
><guimenuitem
>Execute Commands</guimenuitem
></menuchoice
></link
>) to see the result.</para>

<para
>When you typed and executed the commands like above in the code editor you might have noticed one or more of the following things:</para>
<orderedlist>
<listitem
><para
>That &mdash; after executing the commands &mdash; the turtle moves up, draws a line, and then turns a quarter turn to the left. This because you have used the <link linkend="forward"
><userinput
>forward</userinput
></link
> and the <link linkend="turnleft"
><userinput
>turnleft</userinput
></link
> commands.</para>
</listitem>
<listitem>
<para
>That the colour of the code changed while you where typing it: this feature is called <emphasis
>intuitive highlighting</emphasis
> &mdash; different types of commands are highlighted differently. This makes reading large blocks of code more easy.</para>
</listitem>
<listitem>
<para
>That the turtle draws a thin black line.</para>
</listitem>
<listitem>
<para
>Maybe you got an error message. This could simply mean two things: you could have made a mistake while copying the commands, or you should still set the correct language for the &logo; commands (you can do that by choosing <menuchoice
><guimenu
>Settings</guimenu
><guimenuitem
>Configure &kturtle;...</guimenuitem
></menuchoice
>, in the <guilabel
>Language</guilabel
> section).</para>
</listitem>
</orderedlist>

<para
>You will likely understand that <userinput
>forward 90</userinput
> commanded the turtle to move forward leaving a line, and that <userinput
>turnleft 90</userinput
> commanded the turtle to turn 90 <glossterm linkend="degrees"
>degrees</glossterm
> to the left.</para>

<para
>Please see the following links to the reference manual for a complete explanation of the new commands: <userinput
>forward</userinput
>, <userinput
>backward</userinput
>, <userinput
>turnleft</userinput
>, and <userinput
>turnright</userinput
>.</para>
</sect2>

<sect2 id="more-examples">
<title
>More examples</title>
<para
>The first example was very simple, so let us go on!</para>

<para>
<!--translators: if it's not already there, you can copy/paste the translated code below and save it in arrow.logo in your examples folder: tde-i18n/language-code/data/tdeedu/kturtle/ -->
<screen
>canvassize 200,200
canvascolour 0,0,0
pencolour 255,0,0
penwidth 5
clear

go 20,20
direction 135

forward 200
turnleft 135
forward 100
turnleft 135
forward 141
turnleft 135
forward 100
turnleft 45

go 40, 100
</screen>
Again you can type or copy-paste the code to the code editor or open the <filename
>arrow.logo</filename
> file in the <guimenu
>Open examples</guimenu
> folder and execute it (using <link linkend="file-execute"
><menuchoice
><guimenu
>File</guimenu
><guimenuitem
>Execute Commands</guimenuitem
></menuchoice
></link
>) to see the result. In the next examples you are expected to know the drill.</para>

<para
>You might have noticed that this second example uses a lot more code. You have also seen a couple of new commands. Here a short explanation of all the new commands:</para>

<para
><userinput
>canvassize 200,200</userinput
> sets the canvas width and height to 200 <glossterm linkend="pixels"
>pixels</glossterm
>. The width and the height are equal, so the canvas will be a square.</para>

<para
><userinput
>canvascolour 0,0,0</userinput
> makes the canvas black. <userinput
>0,0,0</userinput
> is an <glossterm linkend="rgb"
>RGB-combination</glossterm
> where all values are set to <userinput
>0</userinput
>, which results in black.</para>

<para
><userinput
>pencolor 255,0,0</userinput
> sets the color of the pen to red. <userinput
>255,0,0</userinput
> is an <glossterm linkend="rgb"
>RGB-combination</glossterm
> where only the red value is set to <userinput
>255</userinput
> (fully on) while the others (green and blue) are set to <userinput
>0</userinput
> (fully off). This results in a bright shade of red.</para>

<para
><userinput
>penwidth 5</userinput
> sets the width (the size) of the pen to <userinput
>5</userinput
> <glossterm linkend="pixels"
>pixels</glossterm
>. From now on every line the turtle draw will have a thickness of <userinput
>5</userinput
>, until we change the <userinput
>penwidth</userinput
> to something else.</para>

<para
><userinput
>clear</userinput
> clear the canvas, that is all it does.</para>

<para
><userinput
>go 20,20</userinput
> commands the turtle to go to a certain place on the canvas. Counted from the upper left corner, this place is 20 <glossterm linkend="pixels"
>pixels</glossterm
> across from the left, and 20 <glossterm linkend="pixels"
>pixels</glossterm
> down from the top of the canvas. Note that using the <userinput
>go</userinput
> command the turtle will not draw a line.</para>

<para
><userinput
>direction 135</userinput
> set the turtle's direction. The <userinput
>turnleft</userinput
> and <userinput
>turnright</userinput
> commands change the turtle's angle starting from its current direction. The <userinput
>direction</userinput
> command changes the turtle's angle from zero, and thus is not relative to the turtle previous direction.</para>

<para
>After the <userinput
>direction</userinput
> command a lot of <userinput
>forward</userinput
> and <userinput
>turnleft</userinput
> commands follow. These command do the actual drawing.</para>

<para
>At last another <userinput
>go</userinput
> command is used to move the turtle aside.</para>

<para
>Make sure you follow the links to the reference. The reference explains each command more thoroughly.</para>

</sect2>
</sect1>



<!--        EXTRA SECTIONS CAN BE ADDED TO THE "GETTING STARTED"

<sect1 id="calculations">
<title
>Simple Calculations</title>
<para>
Not yet written
</para>
</sect1>
<sect1 id="using_variables">
<title
>Using Variables: creating 'number containers'</title>
<para>
Not yet written
</para>
</sect1>
<sect1 id="using_strings">
<title
>Using strings: creating 'text containers'</title>
<para>
Not yet written
</para>
</sect1>
<sect1 id="logic">
<title
>Logic: asking the computer simple questions</title>
<para>
Not yet written
</para>
</sect1>
<sect1 id="recursion">
<title
>Recursion: the Turtle is using itself</title>
<para>
Draw a maze for example
</para>
</sect1
>-->


</chapter>