极客教程Fabric.js qrDecompose()方法
qrDecompose()方法 用于将指定的标准2×3矩阵分解为变换组件
语法：
qrDecompose( mat )
参数： 该方法接受一个如上所述并以下方式描述的参数：
- mat： 该参数保存指定的变换矩阵数组。
返回值： 该方法返回变换的组件。
示例1：
<!DOCTYPE html>
<html>
<head>
<!-- Adding the FabricJS library -->
<script src=
"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js">
</script>
</head>
<body>
<script type="text/javascript">
// Calling qrDecompose() function over
// the specified array of transform matrix
console.log(fabric.util
.qrDecompose([1, 2, 3, 4, 5, 6]));
</script>
</body>
</html>
输出:
{"angle":63.434948822922,"scaleX":2.23606797749979,"scaleY":-0.8944271909999159,
"skewX":65.55604521958347,"skewY":0,"translateX":5,"translateY":6}
示例2：
<!DOCTYPE html>
<html>
<head>
<!-- Adding the FabricJS library -->
<script src=
"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js">
</script>
</head>
<body>
<script type="text/javascript">
// Specifying some array of transform matrix
var a1 = [1, 2, 3];
var a2 = [0, 6, 7, 8, 0, 0];
// Calling qrDecompose() function over the
// above specified array of transform matrix
console.log(fabric.util.qrDecompose(a1));
console.log(fabric.util.qrDecompose(a2));
</script>
</body>
</html>
输出：
{"angle":63.434948822922,"scaleX":2.23606797749979,"scaleY":null,"skewX":null,"skewY":0}
{"angle":90,"scaleX":6,"scaleY":-7,"skewX":53.13010235415598,"skewY":0,
"translateX":0,"translateY":0}