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canvas基礎繪制-arc

order draw get style 曲線 ont i++ false canvas

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>arc</title>
</head>
<body>
<canvas id="canvas" style="border: 1px solid #ddd;"></canvas>
<script>
    //draw an arc畫曲線
    var canvas = document.getElementById("canvas");

    canvas.width 
= 1024; canvas.height = 768; var context = canvas.getContext("2d"); context.lineWidth = 5; context.strokeStyle = "#058"; context.arc(300,300,200,0,0.5*Math.PI,true); //context.arc( //conterx,contery,radius,//圓心坐標x,圓心坐標y,半徑 //startingAngle,endingAngle,//起始弧度值,終止弧度值 //anticlockwise = false//false順時針繪制,true逆時針繪制
// ); context.stroke(); </script> </body> </html>

繪制單個圓:

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繪制多個圓:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>arc*n</title>
</head>
<body>
<canvas id="canvas" style="border: 1px solid #ddd"></canvas>
<script>
    var
canvas = document.getElementById("canvas"); canvas.width = 1024; canvas.height = 768; var context = canvas.getContext("2d"); context.lineWidth = 5; context.strokeStyle = "#058"; for(var i=0;i<10;i++){ context.beginPath();//重新開始新的路徑 context.arc(50+100*i,60,40,0,2*Math.PI*(i+1)/10); context.closePath();//結束當前路徑,自動繪制封閉未封閉的線段 context.stroke(); } for(var i=0;i<10;i++){ context.beginPath();//重新開始新的路徑 context.arc(50+100*i,180,40,0,2*Math.PI*(i+1)/10); context.stroke(); } for(var i=0;i<10;i++){ context.beginPath();//重新開始新的路徑 context.arc(50+100*i,300,40,0,2*Math.PI*(i+1)/10,true); context.closePath();//結束當前路徑,自動繪制封閉未封閉的線段 context.stroke(); } for(var i=0;i<10;i++){ context.beginPath();//重新開始新的路徑 context.arc(50+100*i,420,40,0,2*Math.PI*(i+1)/10,true); context.stroke(); } //填充圖形; context.fillStyle = "#058"; for(var i=0;i<10;i++){ context.beginPath();//重新開始新的路徑 context.arc(50+100*i,540,40,0,2*Math.PI*(i+1)/10); context.fill(); } </script> </body> </html>

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canvas基礎繪制-arc