{"id":330,"date":"2009-06-29T05:00:21","date_gmt":"2009-06-29T12:00:21","guid":{"rendered":"https:\/\/actionsnippet.com\/?p=1651"},"modified":"2009-06-29T05:00:21","modified_gmt":"2009-06-29T12:00:21","slug":"2d-map-avoid","status":"publish","type":"post","link":"https:\/\/actionsnippet.com\/?p=330","title":{"rendered":"2D Map Avoid"},"content":{"rendered":"<pre class=\"brush: as3; title: ; notranslate\" title=\"\">\r\n&#x5B;SWF(width=401,height=401,background=0xEFEFEF)]\r\n\r\nvar w:Number = stage.stageWidth-1;\r\nvar h:Number = stage.stageHeight-1;\r\nvar tileSize:Number = 20;\r\nvar halfTileSize:Number = 20;\r\nvar hTiles:Number = w \/ tileSize;\r\nvar vTiles:Number = h \/ tileSize;\r\nvar world:Shape = Shape(addChild(new Shape()));\r\nvar map:Array=&#x5B;];\r\npopulateMap();\r\nvar gridColor:uint = 0xCCCCCC;\r\ngrid(tileSize,  gridColor);\r\n\r\nvTiles -= 1;\r\nvar movers:Array = &#x5B;];\r\nfor (var i:int = 0; i&lt;100; i++){\r\n\tmovers.push(makeMover(i % hTiles, int( i \/ hTiles),0x000000))\r\n\tmovers.push(makeMover(i % hTiles, vTiles - int( i \/ hTiles),0xFF0000))\r\n}\r\nvar moverNum:int = movers.length;\r\nhTiles -= 1;\r\n\r\naddEventListener(Event.ENTER_FRAME, onLoop);\r\nfunction onLoop(evt:Event):void {\r\n\tworld.graphics.clear();\r\n    for (var i:int = 0; i&lt;moverNum; i++){\r\n\t   movers&#x5B;i]();\r\n     }\r\n}\r\nfunction populateMap():void{\r\n\tfor (var i:int = 0; i&lt;vTiles; i++){\r\n\t\tmap&#x5B;i] = &#x5B;];\r\n\t\tfor (var j:int = 0; j&lt;hTiles; j++){\r\n\t\t    map&#x5B;i]&#x5B;j] = 0;\r\n\t\t}\r\n\t}\r\n}\r\nfunction grid(size:Number=30, lineColor:uint=0xFFFF00, lineAlpha:Number=1):void {\r\n    with(graphics){\r\n\t\tlineStyle(0, lineColor, lineAlpha);\r\n\t\tdrawRect(0,0,w,h);\r\n\t\tfor (var i:Number = size; i&lt;w; i+=size) {\r\n\t\t\tmoveTo(i, 0);\r\n\t\t\tlineTo(i, w);\r\n\t\t}\r\n\t\tfor (i = size; i&lt;h; i+=size) {\r\n\t\t\tmoveTo(0, i);\r\n\t\t\tlineTo(h, i);\r\n\t\t}\r\n\t}\r\n}\r\nfunction makeMover(x:Number, y:Number, col:uint):Function{\r\n\tvar xp:Number = x;\r\n\tvar yp:Number = y;\r\n\tvar prevX:Number = x;\r\n\tvar prevY:Number = y;\r\n\tmap&#x5B;yp]&#x5B;xp] = 1;\r\n\tvar dx:Number = xp;\r\n\tvar dy:Number = yp;\r\n\tvar counter:int = 0;\r\n\treturn function():void{\r\n\t\tif (counter &gt; 20){\r\n\t\t\tif (int(Math.random()*30) == 1){\r\n\t\t\t\txp += int(Math.random()*2) - 1 | 1;\r\n\t\t\t\txp = xp &lt; 0 ? 0 : xp;\r\n\t\t\t\txp = xp &gt; hTiles ? hTiles : xp;\r\n\t\t\t\tif (map&#x5B;yp]&#x5B;xp] == 1){\r\n\t\t\t\t\t xp = prevX;\r\n\t\t\t\t}else{\r\n\t\t\t\t\tmap&#x5B;prevY]&#x5B;prevX] = 0;\r\n\t\t\t\t\tmap&#x5B;yp]&#x5B;xp] = 1;\r\n\t\t\t\t\tcounter = 0;\r\n\t\t\t\t}\r\n\t\t\t\tprevX = xp;\r\n\t\t\t}else\r\n\t\t\tif (int(Math.random()*30) == 1){\r\n\t\t\t\typ += int(Math.random()*2) - 1 | 1;\r\n\t\t\t\typ = yp &lt; 0 ? 0 : yp;\r\n\t\t\t\typ = yp &gt; vTiles ? vTiles : yp;\r\n\t\t\t\tif (map&#x5B;yp]&#x5B;xp] == 1){\r\n\t\t\t\t\t yp = prevY;\r\n\t\t\t\t}else{\r\n\t\t\t\t\tmap&#x5B;prevY]&#x5B;prevX] = 0;\r\n\t\t\t\t\tmap&#x5B;yp]&#x5B;xp] = 1;\r\n\t\t\t\t\tcounter = 0;\r\n\t\t\t\t}\r\n\t\t\t\tprevY = yp;\r\n\t\t\t}\r\n\t\t}\r\n\t\tcounter++;\r\n\t\tdx += (xp - dx) * 0.5;\r\n\t\tdy += (yp - dy) * 0.5;\r\n\t\twith(world.graphics){\r\n\t\t\tlineStyle(0, gridColor,1, true)\r\n\t\t\tbeginFill(col);\r\n\t\t\tdrawRect(dx * tileSize, dy * tileSize, tileSize, tileSize);\r\n\t\t}\r\n\t}\r\n}\r\n<\/pre>\n<p>This (somewhat long) snippet moves boxes around on a grid &#8211; the boxes avoid one another by reading values in a 2D array. This technique can also be used for collision detection in tile-based games.<\/p>\n<p><a data-asruffle-linked=\"true\" href=\"https:\/\/actionsnippet.com\/swfs\/map_avoid.html\" target=\"blank\"><br \/>\nHave a look at the swf here&#8230;<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/actionsnippet.com\/wp-content\/avoid_map.gif\" \/><\/a> <span class=\"asruffle-link\" data-swf=\"{&quot;url&quot;:&quot;https:\\\/\\\/actionsnippet.com\\\/swfs\\\/map_avoid.swf&quot;,&quot;title&quot;:&quot;map avoid&quot;,&quot;width&quot;:401,&quot;height&quot;:401,&quot;missing&quot;:false,&quot;allowScriptAccess&quot;:false,&quot;backgroundColor&quot;:&quot;#ffffff&quot;}\"><button type=\"button\" hidden aria-expanded=\"false\">Play demo<span class=\"screen-reader-text\">: map avoid<\/span><\/button><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&#x5B;SWF(width=401,height=401,background=0xEFEFEF)] var w:Number = stage.stageWidth-1; var h:Number = stage.stageHeight-1; var tileSize:Number = 20; var halfTileSize:Number = 20; var hTiles:Number = w \/ tileSize; var vTiles:Number = h \/ tileSize; var world:Shape = Shape(addChild(new Shape())); var map:Array=&#x5B;]; populateMap(); var gridColor:uint = 0xCCCCCC; grid(tileSize, gridColor); vTiles -= 1; var movers:Array = &#x5B;]; for (var i:int = 0; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,13,23],"tags":[3,14,4],"class_list":["post-330","post","type-post","status-publish","format-standard","hentry","category-arrays","category-motion","category-random","tag-actionscript","tag-as3","tag-flash"],"_links":{"self":[{"href":"https:\/\/actionsnippet.com\/index.php?rest_route=\/wp\/v2\/posts\/330","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/actionsnippet.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/actionsnippet.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/actionsnippet.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/actionsnippet.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=330"}],"version-history":[{"count":0,"href":"https:\/\/actionsnippet.com\/index.php?rest_route=\/wp\/v2\/posts\/330\/revisions"}],"wp:attachment":[{"href":"https:\/\/actionsnippet.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=330"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/actionsnippet.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=330"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/actionsnippet.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=330"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}