<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 — after executing the commands — 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 > — 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: kde-i18n/language-code/data/kdeedu/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>
