<snapdata remixID="8927791"><project name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"><notes></notes><thumbnail>data:image/png;base64,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</thumbnail><stage name="Stage" width="480" height="360" costume="0" color="255,255,255,1" tempo="60" threadsafe="false" volume="100" pan="0" lines="flat" ternary="true" codify="false" inheritance="false" sublistIDs="false" scheduled="false" id="1"><pentrails>data:image/png;base64,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</pentrails><costumes><list struct="atomic" id="2"></list></costumes><sounds><list struct="atomic" id="3"></list></sounds><variables></variables><blocks></blocks><scripts></scripts><sprites><sprite name="Sprite" idx="1" x="145" y="130" heading="90" scale="1" volume="100" pan="0" rotation="1" draggable="true" costume="0" color="255,47,31,1" pen="tip" id="8"><costumes><list struct="atomic" id="9"></list></costumes><sounds><list struct="atomic" id="10"></list></sounds><blocks></blocks><variables></variables><scripts><script x="23" y="10"><block s="clear"></block></script><script x="49" y="296"><custom-block s="draw checkboard %n"><l>8</l></custom-block></script></scripts></sprite></sprites></stage><hidden></hidden><headers></headers><code></code><blocks><block-definition s="draw black square size %&apos;size&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input></inputs><script><block s="setColor"><color>8,5,0,1</color></block><custom-block s="set flat line ends to %b"><block s="reportBoolean"><l><bool>true</bool></l></block></custom-block><block s="setSize"><block var="size"/></block><block s="down"></block><block s="forward"><block var="size"/></block><block s="up"></block></script></block-definition><block-definition s="draw red square size %&apos;size&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input></inputs><script><block s="setColor"><color>255,47,31,1</color></block><custom-block s="set flat line ends to %b"><block s="reportBoolean"><l><bool>true</bool></l></block></custom-block><block s="setSize"><block var="size"/></block><block s="down"></block><block s="forward"><block var="size"/></block><block s="up"></block></script></block-definition><block-definition s="draw checkboard %&apos;number&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input></inputs><script><block s="doDeclareVariables"><list><l>x value</l><l>y value</l></list></block><block s="doSetVar"><l>y value</l><l>-150</l></block><block s="doSetVar"><l>x value</l><l>-175</l></block><block s="doFor"><l>row</l><l>1</l><block var="number"/><script><block s="gotoXY"><block var="x value"/><block var="y value"/></block><block s="doIfElse"><block s="reportEquals"><block s="reportModulus"><block var="row"/><l>2</l></block><l>1</l></block><script><custom-block s="row a"></custom-block></script><script><custom-block s="row b"></custom-block></script></block><block s="doChangeVar"><l>y value</l><l>40</l></block></script></block></script></block-definition><block-definition s="set flag %&apos;which&apos; to %&apos;tf&apos;" type="command" category="sensing"><header></header><code></code><translations></translations><inputs><input type="%s" readonly="true"><options>Presentation mode&#xD;Retina display support&#xD;Long form input dialog&#xD;Plain prototype labels&#xD;Input sliders&#xD;Execute on slider change&#xD;Clicking sound&#xD;Turbo mode&#xD;Flat design&#xD;Keyboard editing&#xD;Table support&#xD;Table lines&#xD;Visible stepping&#xD;Thread safe scripts&#xD;Prefer smooth animations&#xD;Flat line ends&#xD;Codification support&#xD;Inheritance support</options></input><input type="%b"></input></inputs><script><block s="doRun"><block s="reportJSFunction"><list><l>which</l><l>tf</l></list><l>var   stage = this.parentThatIsA(StageMorph),&#xD;        ide = stage.parentThatIsA(IDE_Morph),&#xD;        world = stage.parentThatIsA(WorldMorph);&#xD;&#xD;if (tf != !!tf) return;&#xD;&#xD;try{&#xD;ide.savingPreferences = false;&#xD;&#xD;switch (which) {&#xD;    case &apos;Presentation mode&apos;:&#xD;        if (tf != ide.isAppMode) ide.toggleAppMode();&#xD;        break;&#xD;    case &apos;Retina display support&apos;:&#xD;        if (tf != isRetinaEnabled()) ide.toggleRetina();&#xD;        break;&#xD;    case &apos;Long form input dialog&apos;:&#xD;        if (tf != InputSlotDialogMorph.prototype.isLaunchingExpanded)&#xD;            ide.toggleLongFormInputDialog();&#xD;        break;&#xD;    case &apos;Plain prototype labels&apos;:&#xD;        if (tf != BlockLabelPlaceHolderMorph.prototype.plainLabel)&#xD;            ide.togglePlainPrototypeLabels();&#xD;        break;&#xD;    case &apos;Input sliders&apos;:&#xD;        MorphicPreferences.useSliderForInput = tf;&#xD;        break;&#xD;    case &apos;Execute on slider change&apos;:&#xD;        ArgMorph.prototype.executeOnSliderEdit = tf;&#xD;        break;&#xD;    case &apos;Clicking sound&apos;:&#xD;        if (tf != !!BlockMorph.prototype.snapSound)&#xD;            BlockMorph.prototype.toggleSnapSound();&#xD;        break;&#xD;    case &apos;Turbo mode&apos;:&#xD;        if (tf != stage.isFastTracked)&#xD;            ide.toggleFastTracking();&#xD;        break;&#xD;    case &apos;Flat design&apos;:&#xD;        if (tf == MorphicPreferences.isFlat) break;&#xD;        if (tf)&#xD;            ide.flatDesign();&#xD;        else&#xD;            ide.defaultDesign();&#xD;        break;&#xD;    case &apos;Keyboard editing&apos;:&#xD;            ScriptsMorph.prototype.enableKeyboard = tf;&#xD;        break;&#xD;    case &apos;Table support&apos;:&#xD;            List.prototype.enableTables = tf;&#xD;        break;&#xD;    case &apos;Table lines&apos;:&#xD;                TableMorph.prototype.highContrast = tf;&#xD;        break;&#xD;    case &apos;Visible stepping&apos;:&#xD;        if (tf != Process.prototype.enableSingleStepping)&#xD;            ide.toggleSingleStepping();&#xD;        break;&#xD;    case &apos;Thread safe scripts&apos;:&#xD;        stage.isThreadSafe = tf;&#xD;        break;&#xD;    case &apos;Prefer smooth animations&apos;:&#xD;        if (tf != (StageMorph.prototype.frameRate &gt; 0))&#xD;            ide.toggleVariableFrameRate();&#xD;        break;&#xD;    case &apos;Flat line ends&apos;:&#xD;        SpriteMorph.prototype.useFlatLineEnds = tf;&#xD;        break;&#xD;    case &apos;Codification support&apos;:&#xD;        if (tf != StageMorph.prototype.enableCodeMapping) {&#xD;            StageMorph.prototype.enableCodeMapping = tf;&#xD;            ide.currentSprite.blocksCache.variables = null;&#xD;            ide.currentSprite.paletteCache.variables = null;&#xD;            ide.refreshPalette();&#xD;        }&#xD;        break;&#xD;    case &apos;Inheritance support&apos;:&#xD;        if (tf != StageMorph.prototype.enableInheritance) {&#xD;            StageMorph.prototype.enableInheritance = tf;&#xD;            ide.currentSprite.blocksCache.variables = null;&#xD;            ide.currentSprite.paletteCache.variables = null;&#xD;            ide.refreshPalette();&#xD;        }&#xD;        break;&#xD;};&#xD;}&#xD;finally {&#xD;ide.savingPreferences = false;&#xD;};&#xD;</l></block><list><block var="which"/><block var="tf"/></list></block></script></block-definition><block-definition s="draw brick, length: %&apos;length&apos; width: %&apos;width&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%n"></input><input type="%n"></input></inputs><script><block s="setColor"><color>145,26,68,1</color></block><custom-block s="set flat line ends to %b"><block s="reportBoolean"><l><bool>true</bool></l></block></custom-block><block s="setSize"><block var="width"/></block><block s="down"></block><block s="forward"><block var="length"/></block><block s="up"></block></script></block-definition><block-definition s="set flat line ends to %&apos;flag&apos;" type="command" category="pen"><header></header><code></code><translations></translations><inputs><input type="%b"></input></inputs><script><custom-block s="set flag %s to %b"><l>Flat line ends</l><block var="flag"/></custom-block></script></block-definition><block-definition s="row a" type="command" category="pen"><header></header><code></code><translations></translations><inputs></inputs><script><block s="down"></block><block s="doRepeat"><l>4</l><script><custom-block s="draw red square size %n"><l>40</l></custom-block><custom-block s="draw black square size %n"><l>40</l></custom-block></script></block></script></block-definition><block-definition s="row b" type="command" category="pen"><header></header><code></code><translations></translations><inputs></inputs><script><block s="down"></block><block s="doRepeat"><l>4</l><script><custom-block s="draw black square size %n"><l>40</l></custom-block><custom-block s="draw red square size %n"><l>40</l></custom-block></script></block></script></block-definition></blocks><variables><variable name="snap"><l>&lt;!DOCTYPE html&gt;&#xD;&lt;html&gt;&#xD;    &lt;head&gt;&#xD;	&lt;meta name="snap-cloud-domain" location="https://cloud.snap.berkeley.edu:443"&gt;&#xD;        &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;&#xD;        &lt;title&gt;Snap! Build Your Own Blocks 5.1.0&lt;/title&gt;&#xD;        &lt;link rel="shortcut icon" href="src/favicon.ico"&gt;&#xD;        &lt;script type="text/javascript" src="src/morphic.js?version=2019-08-06"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/widgets.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/blocks.js?version=2019-08-07"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/threads.js?version=2019-08-07"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/objects.js?version=2019-08-08"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/gui.js?version=2019-08-08"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/paint.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/lists.js?version=2019-07-01"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/byob.js?version=2019-07-24"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/tables.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/symbols.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/sketch.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/video.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/maps.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/xml.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/store.js?version=2019-08-08"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/locale.js?version=2019-08-07"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/cloud.js?version=2019-07-17"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/sha512.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript" src="src/FileSaver.min.js?version=2019-06-27"&gt;&lt;/script&gt;&#xD;        &lt;script type="text/javascript"&gt;&#xD;            var world;&#xD;            window.onload = function () {&#xD;                world = new WorldMorph(document.getElementById(&apos;world&apos;));&#xD;                new IDE_Morph().openIn(world);&#xD;                loop();&#xD;			};&#xD;            function loop() {&#xD;                requestAnimationFrame(loop);&#xD;                world.doOneCycle();&#xD;            }&#xD;        &lt;/script&gt;&#xD;    &lt;/head&gt;&#xD;    &lt;body style="margin: 0;"&gt;&#xD;        &lt;canvas id="world" tabindex="1" style="position: absolute;" /&gt;&#xD;    &lt;/body&gt;&#xD;&lt;/html&gt;&#xD;</l></variable></variables></project><media name="U2L4-checkerboard_SV" app="Snap! 5.1, http://snap.berkeley.edu" version="1"></media></snapdata>