Graph edge's lines are sometimes rounded to wrong position by subPixelOptmize

### Version
5.0.1

### Reproduction link
[https://codesandbox.io/s/young-cache-2jkt8?file=/src/App.tsx](https://codesandbox.io/s/young-cache-2jkt8?file=/src/App.tsx)

### Steps to reproduce
See the codesandbox

### What is expected?
graph edge positions should be corrent.

### What is actually happening?
If you clicked the reset button, sometimes one (sometimes more than one) of the edge has a wrong position, it will become y1 === y2 or x1 === x2 when it shouldn't.

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it's caused by subPixelOptimize, if disable subPixelOptimize in line, it works. It seems the "x1, x2, y1, y2" passed to subPixelOptimize are not the line's true pixel position but a small fraction number like 0.05, but style.lineWidth is counted by pixel, which maybe much larger like 3, causeing this issue.