{"id":409,"date":"2009-09-16T06:51:17","date_gmt":"2009-09-16T13:51:17","guid":{"rendered":"https:\/\/actionsnippet.com\/?p=2201"},"modified":"2009-09-16T06:51:17","modified_gmt":"2009-09-16T13:51:17","slug":"quickbox2d-contacts-part-3","status":"publish","type":"post","link":"https:\/\/actionsnippet.com\/?p=409","title":{"rendered":"QuickBox2D Contacts Part 3"},"content":{"rendered":"
\r\nimport com.actionsnippet.qbox.*;\r\nimport Box2D.Common.Math.*;\r\n\r\n[SWF(width = 800, height = 600, backgroundColor = 0x222222, frameRate=60)]\r\n\r\nvar sim:QuickBox2D = new QuickBox2D(this, {debug:false});\r\n\r\nsim.createStageWalls();\r\n\r\nvar cup:QuickObject = sim.addPoly({x:3, y:13, wireframe:false, density:0, \r\n\t\t\t\t\t\t\t\t   points:[0,0, .5, 0, .5,3,  2,3,  2,0,  2.5,0, 2.5, 3.5, 0, 3.5, 0,0]});\r\nvar deleter:QuickObject = sim.addBox({x:4.251, y: 15.9, width:1.5, height:0.25, fillColor:0xFF0000});\r\n\r\n\/\/ use a distance joint instead of a group since isCurrentContact \r\n\/\/ uses the QuickObject.body property\r\nsim.addJoint({a:cup.body, b:deleter.body, x1:deleter.x, y1:deleter.y+0.5});\r\n\r\nvar circles:Array = [];\r\nfor (var i:int = 0; i<10; i++){\r\n\tcircles[i] = sim.addCircle({x:8 + i, y:5, radius:0.5});\r\n}\r\nvar boxes:Array = [];\r\nfor (i = 0; i<10; i++){\r\n\tboxes[i] = sim.addBox({x:8.5 + i, y:10, width:0.5, height:0.5});\r\n}\r\n\r\nsim.start();\r\nsim.mouseDrag();\r\n\r\nvar shootVec:b2Vec2 = new b2Vec2(4, -30);\r\n\r\n\/\/ when circles are dropped in the cup they are destroyed\r\n\/\/ when boxes are droppped in the cup their linear velocity is altered\r\nvar contacts:QuickContacts = sim.addContactListener();\r\ncontacts.addEventListener(QuickContacts.ADD, onAdd);\r\nfunction onAdd(evt:Event):void{\r\n\tfor (var i:int = 0; i<circles.length; i++){\r\n\t\tvar circ:QuickObject = circles[i];\r\n\t\tif (contacts.isCurrentContact(circ, deleter)){\r\n\t\t\t\/\/ it's ok to destroy QuickObject here because they are only actually\r\n\t\t\t\/\/ destroyed after the timeStep has finished at the end of QuickBox2D's \r\n\t\t\t\/\/ internal loop\r\n\t\t\tcirc.destroy();\r\n\t\t}\r\n\t } \r\n\t for (i = 0; i<boxes.length; i++){\r\n\t\tvar box:QuickObject = boxes[i];\r\n\t\tif (contacts.isCurrentContact(box, deleter)){\r\n\t\t\tbox.body.SetLinearVelocity(shootVec);\r\n\t\t}\r\n\t }\r\n}\r\n<\/pre>\n
Note: This snippet requires QuickBox2D 1.0 or greater<\/a><\/i><\/p>\n
Here is another example of using QuickBox2D style contacts. In this example there is a cup with a small red box inside of it. When circles are placed inside the cup they are destroyed. When boxes are placed inside the cup they are shot upward. <\/p>\n

\nHave a look at the swf…<\/p>\n
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