L-System | JavaScript 程式專案

{"id":25998,"student_id":7,"content":"// noprotect\nstopRendering();\npen.fillColor = 'white';\npen.drawRect(0, 0, 640, 480);\n\n// L System\nlet axiom = 'F';\nlet sentence = axiom;\nlet rules =[\n    {\n        char: 'F',\n        to: 'FF+[+F-F-F]-[-F+F=F]'\n    }\n]\nlet state = { x: 320, y: 480, angle: 0 };\nlet oldStates = [];\nlet rotateDeg = 25;\nlet lineLen = 5;\nlet lines = [];\n\nfunction generate() {\n    let nextSentence = '';\n    for (let char of sentence) {\n        for(let rule of rules) {\n            if (char === rule.char) {\n                nextSentence += rule.to;\n            } else {\n                nextSentence += char;\n            }\n        }\n    }\n\n    sentence = nextSentence;\n}\n\nfunction turtle() {\n    for (let char of sentence) {\n        if (char === 'F') {\n            pen.drawLine(...getLineArgs());\n        } else if (char === '+') {\n            state.angle += rotateDeg;\n        } else if (char === '-') {\n            state.angle -= rotateDeg;\n        } else if (char === '[') {\n            let copiedObj = Object.assign({}, state);\n            oldStates.push(copiedObj);\n        } else if (char === ']') {\n            state = oldStates.pop();\n        }\n    }\n}\n\nfunction getLineArgs() {\n    let endX = state.x + (lineLen * Math.sin(Math.PI / 180 * state.angle));\n    let endY = state.y - (lineLen * Math.cos(Math.PI / 180 * state.angle));\n    let result = [state.x, state.y, endX, endY];\n    \n    // translate origin\n    state.x = endX;\n    state.y = endY;\n    \n    return result;\n}\n\nwhen('click', function() {\n    state = { x: 320, y: 480, angle: 0 };\n    oldStates = [];\n    rotateDeg = 25;\n\n    generate();\n    turtle();\n});\n\n","created_at":"2018-04-01T13:59:59.685+08:00","updated_at":"2019-11-12T09:47:34.221+08:00","name":"L-System","language":"javascript","screenshot":{"url":"https://cdn7.koding.school/uploads/project/screenshot/25998/fd1ac05835b665cf0d7e3c5532c7c2d7.jpg"},"parent_id":2,"plugin":"","description":null,"note":null,"status":"public","like_student_ids":[],"is_featured":false,"views":433,"hashid":"kdmsj2rz","is_content_changed":false,"review_status":"unsubmitted","submitted_at":null,"reviewed_at":null,"advise":null,"is_deleted":false}