如何在SVG中设置变换原点 [英] How to set transform origin in SVG

问题描述

我需要使用JavaScript调整SVG文档中的某些元素的大小并旋转它们.问题是，默认情况下，它总是围绕(0, 0) –左上方的原点应用变换.

I need to resize and rotate certain elements in SVG document using javascript. The problem is, by default, it always applies the transform around the origin at (0, 0) – top left.

如何重新定义此变换锚点?

How can I re-define this transform anchor point?

我尝试使用transform-origin属性，但它不会影响任何内容.

I tried using the transform-origin attribute, but it does not affect anything.

这是我的方法:

svg.getDocumentById('someId').setAttribute('transform-origin', '75 240');

尽管我可以在Firefox中看到正确设置了属性，但似乎没有将枢轴点设置为我指定的点.我尝试了带或不带括号的center bottom和50% 100%之类的东西.到目前为止，什么都没有.

It does not seem to set the pivotal point to the point I specified although I can see in Firefox that the attribute is correctly set. I tried things like center bottom and 50% 100% with and without parenthesis. Nothing worked so far.

任何人都可以帮忙吗?

推荐答案

要旋转，请使用transform="rotate(deg, cx, cy)"，其中deg是要旋转的度数，而(cx，cy)定义旋转中心.

To rotate use transform="rotate(deg, cx, cy)", where deg is the degree you want to rotate and (cx, cy) define the centre of rotation.

要缩放/调整大小，您必须先按(-cx，-cy)进行转换，然后进行缩放，然后再转换回(cx，cy).您可以通过矩阵变换来实现:

For scaling/resizing, you have to translate by (-cx, -cy), then scale and then translate back to (cx, cy). You can do this with a matrix transform:

transform="matrix(sx, 0, 0, sy, cx-sx*cx, cy-sy*cy)"

其中sx是x轴的比例因子，sy是y轴.

Where sx is the scaling factor in the x-axis, sy in the y-axis.

这篇关于如何在SVG中设置变换原点的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！