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diff --git a/files/zh-cn/web/api/canvasrenderingcontext2d/beziercurveto/index.html b/files/zh-cn/web/api/canvasrenderingcontext2d/beziercurveto/index.html new file mode 100644 index 0000000000..5a66c1f6e8 --- /dev/null +++ b/files/zh-cn/web/api/canvasrenderingcontext2d/beziercurveto/index.html @@ -0,0 +1,191 @@ +--- +title: CanvasRenderingContext2D.bezierCurveTo() +slug: Web/API/CanvasRenderingContext2D/bezierCurveTo +tags: + - API + - Canvas + - CanvasRenderingContext2D + - Method + - Reference +translation_of: Web/API/CanvasRenderingContext2D/bezierCurveTo +--- +<div>{{APIRef}}</div> + +<p><code><strong>CanvasRenderingContext2D</strong></code><strong><code>.bezierCurveTo()</code></strong> 是 Canvas 2D API 绘制三次贝赛尔曲线路径的方法。 该方法需要三个点。 第一、第二个点是控制点，第三个点是结束点。起始点是当前路径的最后一个点，绘制贝赛尔曲线前，可以通过调用 <code>moveTo()</code> 进行修改。</p> + +<h2 id="语法">语法</h2> + +<pre class="syntaxbox">void <var><em>ctx</em>.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);</var> +</pre> + +<h3 id="参数">参数</h3> + +<dl> + <dt><code>cp1x</code></dt> + <dd>第一个控制点的 x 轴坐标。</dd> + <dt><code>cp1y</code></dt> + <dd>第一个控制点的 y 轴坐标。</dd> + <dt><code>cp2x</code></dt> + <dd>第二个控制点的 x 轴坐标。</dd> + <dt><code>cp2y</code></dt> + <dd>第二个控制点的 y 轴坐标。</dd> + <dt><code>x</code></dt> + <dd>结束点的 x 轴坐标。</dd> + <dt><code>y</code></dt> + <dd>结束点的 y 轴坐标。</dd> +</dl> + +<h2 id="示例">示例</h2> + +<h3 id="使用_bezierCurveTo_方法">使用 <code>bezierCurveTo</code> 方法</h3> + +<p>这是一段绘制贝赛尔曲线的简单的代码片段。 <span style="color: red;">控制点是红色的</span>，<span style="color: blue;"> 开始和结束点是蓝色的。</span></p> + +<h4 id="HTML">HTML</h4> + +<pre class="brush: html"><canvas id="canvas"></canvas> +</pre> + +<h4 id="JavaScript">JavaScript</h4> + +<pre class="brush: js; highlight:[6]">var canvas = document.getElementById("canvas"); +var ctx = canvas.getContext("2d"); + +ctx.beginPath(); +ctx.moveTo(50,20); +ctx.bezierCurveTo(230, 30, 150, 60, 50, 100); +ctx.stroke(); + +ctx.fillStyle = 'blue'; +// start point +ctx.fillRect(50, 20, 10, 10); +// end point +ctx.fillRect(50, 100, 10, 10); + +ctx.fillStyle = 'red'; +// control point one +ctx.fillRect(230, 30, 10, 10); +// control point two +ctx.fillRect(150, 70, 10, 10);</pre> + +<p>{{ EmbedLiveSample('使用_bezierCurveTo_方法', 315, 165) }}</p> + +<h3 id="尝试_bezierCurveTo_参数">尝试 <code>bezierCurveTo</code> 参数</h3> + +<p>修改下面的代码并在线查看 canvas 的变化：</p> + +<div style="display: none;"> +<pre class="brush: html"><canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas> +<div class="playable-buttons"> + <input id="edit" type="button" value="Edit" /> + <input id="reset" type="button" value="Reset" /> +</div> +<textarea id="code" class="playable-code"> +ctx.beginPath(); +ctx.bezierCurveTo(50, 100, 180, 10, 20, 10); +ctx.stroke();</textarea> +</pre> + +<pre class="brush: js">var canvas = document.getElementById("canvas"); +var ctx = canvas.getContext("2d"); +var textarea = document.getElementById("code"); +var reset = document.getElementById("reset"); +var edit = document.getElementById("edit"); +var code = textarea.value; + +function drawCanvas() { + ctx.clearRect(0, 0, canvas.width, canvas.height); + eval(textarea.value); +} + +reset.addEventListener("click", function() { + textarea.value = code; + drawCanvas(); +}); + +edit.addEventListener("click", function() { + textarea.focus(); +}) + +textarea.addEventListener("input", drawCanvas); +window.addEventListener("load", drawCanvas); +</pre> +</div> + +<p>{{ EmbedLiveSample('尝试_bezierCurveTo_参数', 700, 360) }}</p> + +<h2 id="规范描述">规范描述</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Specification</th> + <th scope="col">Status</th> + <th scope="col">Comment</th> + </tr> + <tr> + <td>{{SpecName('HTML WHATWG', "scripting.html#dom-context-2d-beziercurveto", "CanvasRenderingContext2D.beziercurveto")}}</td> + <td>{{Spec2('HTML WHATWG')}}</td> + <td> </td> + </tr> + </tbody> +</table> + +<h2 id="浏览器兼容性">浏览器兼容性</h2> + +<p>{{CompatibilityTable}}</p> + +<div id="compat-desktop"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Chrome</th> + <th>Firefox (Gecko)</th> + <th>Internet Explorer</th> + <th>Opera</th> + <th>Safari</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + </tr> + </tbody> +</table> +</div> + +<div id="compat-mobile"> +<table class="compat-table"> + <tbody> + <tr> + <th>Feature</th> + <th>Android</th> + <th>Chrome for Android</th> + <th>Firefox Mobile (Gecko)</th> + <th>IE Mobile</th> + <th>Opera Mobile</th> + <th>Safari Mobile</th> + </tr> + <tr> + <td>Basic support</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + <td>{{CompatVersionUnknown}}</td> + </tr> + </tbody> +</table> +</div> + +<h2 id="参见">参见</h2> + +<ul> + <li>接口定义， {{domxref("CanvasRenderingContext2D")}}</li> + <li><a href="http://en.wikipedia.org/wiki/B%C3%A9zier_curve">维基百科关于贝赛尔曲线</a>。</li> +</ul> |