詳解如何用canvas畫一個(gè)微笑的表情

2024-09-05 07:19:36

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供稿：網(wǎng)友

實(shí)習(xí)期間讓我用canvas畫一個(gè)表情，比較簡(jiǎn)單，話不多說直接上代碼：

<body><div id="canvas-warp">    <canvas id="canvas" style="display: block; margin: 200px auto;">        你的瀏覽器居然不支持Canvas!    </canvas></div><script>    window.onload = function () {        var canvas = document.getElementById("canvas");        canvas.width = 400;        canvas.height = 400;        //獲取上下文        var context = canvas.getContext("2d");        //用于畫有填充色圓的函數(shù)  參數(shù)分別為圓心坐標(biāo) ，半徑，起始與終止位置，線顏色，填充顏色        function drawCircle(x2, y2, r2, a2, b2, lineColor, FillColor) {            context.beginPath();            context.arc(x2, y2, r2, a2, b2 * Math.PI);            context.strokeStyle = lineColor;            context.fillStyle = FillColor;            context.fill(); //確認(rèn)填充            context.stroke();        };        //用于畫圓弧函數(shù) 默認(rèn)線條為黑色 無(wú)填充 參數(shù)分別為：圓心x坐標(biāo)，圓心y坐標(biāo)，半徑，開始位置，終止位置        function drawsArc(x, y, r, l1, l2) {            context.beginPath();            context.arc(x, y, r, l1 * Math.PI, l2 * Math.PI);            context.strokeStyle = "black";            context.stroke();        };        //用于畫眼睛的函數(shù)        function darwEyes(x1, y1, a1, b1) { //參數(shù)分別為橢圓圓心位置 長(zhǎng)軸  短軸            context.strokeStyle = "#754924"            ParamEllipse(context, x1, y1, a1, b1); //橢圓            function ParamEllipse(context, x, y, a, b) {                //使每次循環(huán)所繪制的路徑（弧線）接近1像素                var step = (a > b) ? 1 / a : 1 / b;                context.beginPath();                context.moveTo(x + a, y); //從橢圓的左端點(diǎn)開始繪制                for (var i = 0; i < 2 * Math.PI; i += step) {                    //參數(shù)為i，表示度數(shù)（弧度）                    context.lineTo(x + a * Math.cos(i), y + b * Math.sin(i));                }                context.closePath();                context.fillStyle = "#754924";                context.fill();                 context.stroke();            };        };        //臉        drawCircle(200, 200, 200, 0, 2, "#EEE685", "#FCF200");        //左眼        context.strokeStyle = "#754924"        darwEyes(116, 130, 18, 25);        drawCircle(110, 127, 12, 0, 2, "#754924", "#F5F5F5");        //右眼        darwEyes(296, 130, 18, 25);        drawCircle(290, 127, 12, 0, 2, "#754924", "#F5F5F5");        //左眉毛        drawsArc(100, 100, 50, 1.3, 1.7);        //右眉毛        drawsArc(300, 100, 50, 1.3, 1.7);        //嘴巴        drawsArc(200, 120, 180, 0.3, 0.7);    }</script></body>

效果圖