开源：WeZRender - 微信小程序Canvas增强组件

   <h2>WeZRender：微信小程序Canvas增强组件</h2>    <p style="text-align:center"><img src="https://simg.open-open.com/show/22351aecfb356e031df15b66dcfb06f1.gif"></p>    <p>WeZRender是一个微信小程序Canvas增强组件，基于HTML5 Canvas类库ZRender。</p>    <h2>使用</h2>    <p>WXML：</p>    <pre>  <code class="language-javascript"><canvas style="width: 375px; height: 600px;" canvas-id="line-canvas-1"></canvas></code></pre>    <p>JS：</p>    <pre>  <code class="language-javascript">var wezrender = require('../../lib/wezrender');        zr = wezrender.zrender.init("line-canvas-1", 375, 600);</code></pre>    <h2>特性</h2>    <p>数据驱动</p>    <p>利用WeZRender绘图，只需定义图形数据。</p>    <pre>  <code class="language-javascript">var circle = new wezrender.graphic.shape.Circle(                shape: {              cx: 50,              cy: 50,              r: 50          },          style: {              fill: 'red',              lineWidth: 10          }      });</code></pre>    <p>丰富的图形选项</p>    <p>内置多种图形元素（圆形、椭圆、圆环、扇形、矩形、多边形、直线、曲线、心形、水滴、玫瑰线、Trochoid、文字、图片等），统一且丰富的图形属性充分满足个性化需求。</p>    <pre>  <code class="language-javascript">var droplet = new wezrender.graphic.shape.Droplet({          shape: {              cx: 200,              cy: 300,              width: 50,              height: 50          },          style: {                  fill: '#ff9999'          }      });</code></pre>    <p>强大的动画支持</p>    <p>提供promise式的动画接口和常用缓动函数，轻松实现各种动画需求。</p>    <pre>  <code class="language-javascript">var image = new wezrender.graphic.Image({          style: {              x: 0,              y: 0,              image: '../../images/koala.jpg',              width: 32,              height: 24,              text: 'koala'          }      });      zr.add(image);        image.animateStyle(true)          .when(2000, {              x: 350,              y: 450,              width: 360,              height: 270,          })          .start();</code></pre>    <p>易于扩展</p>    <p>分而治之的图形定义策略允许扩展图形元素。</p>    <pre>  <code class="language-javascript">var Pin = wezrender.graphic.Path.extend({          type: 'pin',          shape: {              // x, y on the cusp              x: 0,              y: 0,              width: 0,              height: 0          },          buildPath: function (path, shape) {              var x = shape.x;              var y = shape.y;              var w = shape.width / 5 * 3;              // Height must be larger than width              var h = Math.max(w, shape.height);              var r = w / 2;                // Dist on y with tangent point and circle center              var dy = r * r / (h - r);              var cy = y - h + r + dy;              var angle = Math.asin(dy / r);              // Dist on x with tangent point and circle center              var dx = Math.cos(angle) * r;                var tanX = Math.sin(angle);              var tanY = Math.cos(angle);                path.arc(                  x, cy, r,                  Math.PI - angle,                  Math.PI * 2 + angle              );                var cpLen = r * 0.6;              var cpLen2 = r * 0.7;              path.bezierCurveTo(                  x + dx - tanX * cpLen, cy + dy + tanY * cpLen,                  x, y - cpLen2,                  x, y              );              path.bezierCurveTo(                  x, y - cpLen2,                  x - dx + tanX * cpLen, cy + dy + tanY * cpLen,                  x - dx, cy + dy              );              path.closePath();          }      });</code></pre>    <p> </p>    <p> </p>