将画布原点设置到左下角 [英] Set canvas origin to the lower-left corner

问题描述

是否可以将原点设置在画布的左下角？我尝试按− 1进行缩放，但此后一切都颠倒了。我需要制作类似坐标系的东西，但只包含正部分（第一象限）。因此，我需要它从左下角的0.0开始。

Is there a way to set the origin to lower-left of the canvas? I tried scaling by −1 but after that everything is upside down. I need to make something like a coordinate system but only with the positive part (first quadrant). So I need it to start with 0.0 at down-left corner.

推荐答案

ctx.translate(0, canvas.height);
ctx.scale(1, -1);

请参阅JSFiddle上的演示。

See a demo on JSFiddle.

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