Flutter CustomPainter画布旋转枢轴 [英] Flutter CustomPainter canvas rotate pivot

问题描述

在我的 Android Studio 项目中，我简单地旋转画布，如下所示

In my Android Studio project, I rotate the canvas simply as following

canvas.rotate(angle, cx, cy);

cx 和 cy 是屏幕的中心(即枢轴).但是在 Flutter 中，只有一个 rotate 方法:

with cx and cy the center of the screen (i.e. the pivot). But in Flutter, there's only a single rotate method:

canvas.rotate(双弧度)

正如你所看到的，当我通过绘制一些矩形并旋转它来测试它使用的枢轴时

and as you can see, when I tested the pivot it uses by drawing some rectangles and rotating it

它使用左上角作为枢轴点.有没有办法指示 Flutter 使用我自己提供的枢轴点?

and it uses top-left as pivot point. Is there a way to instruct Flutter to use my own provided pivot point?

推荐答案

canvas.translate(cx, cy);
canvas.rotate(angle);
canvas.translate(-cx, -cy);

我的第 1 行和第 3 行可能颠倒了.已修复.

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