公轉軌跡 | JavaScript 程式專案

{"id":8233,"student_id":1470,"content":"var pen = Game.pen;\nvar numOfBalls = 4;\nvar balls = [];\nvar ballPosition = [];\nvar radius = 100;\npen.size = 1;\n\nfor (var i = 0; i \u003c numOfBalls; i++) {\n    balls.push({\n        bias: Math.PI/(numOfBalls+1)*i*(Math.random()+1),\n        biasQ: Math.PI/(numOfBalls)*i*(Math.random()+1),\n        velocity: Math.random()*0.3,\n        // velocity: (Math.random()-0.5)/10,\n        amplitude: {x: radius, y: radius},\n        // amplitude: {x: Math.random() * radius, y: Math.random() * radius},\n        angle: 0,\n        oscillate: function () {\n            this.angle += this.velocity;\n        },\n        display: function () {\n            var x = Math.cos(this.angle) * radius * Math.cos(this.bias)+ 320;\n            var y = Math.sin(this.angle) * radius * Math.cos(this.biasQ)+ 240;\n            pen.drawCircle(x, y, 5);\n            pen.drawLine(320, 240, x, y);\n            ballPosition.push({x: x, y: y});\n            if(ballPosition.length\u003enumOfBalls*300){\n                ballPosition.splice(0,1);\n            }\n        },\n        update: function () {\n            this.oscillate();\n            this.display();\n            for(var i = 0; i \u003c ballPosition.length; i++){\n                pen.color = \"#333\";\n                pen.drawRect(ballPosition[i].x, ballPosition[i].y, 1, 1);\n            }\n            pen.color = \"black\";\n        }\n    });\n\n}\n\nforever(function () {\n    if(balls.length \u003e= numOfBalls){\n        for (var i = 0; i \u003c numOfBalls; i++) {\n            balls[i].update();\n        }\n        \n    }\n    \n})\n\n","created_at":"2017-03-01T20:52:04.729+08:00","updated_at":"2019-11-09T19:14:14.244+08:00","name":"公轉軌跡","language":"javascript","screenshot":{"url":"https://cdn1.koding.school/uploads/project/screenshot/8233/da786cdddf9c9e70c6e3f0694aba919f.jpg"},"parent_id":2,"plugin":"","description":null,"note":null,"status":"public","like_student_ids":[],"is_featured":false,"views":470,"hashid":"9ygskjp","is_content_changed":null,"review_status":"unsubmitted","submitted_at":null,"reviewed_at":null,"advise":null,"is_deleted":false}