Line annotation when specified with borderWidth:1, the final width of line is 2px about chartjs-plugin-annotation HOT 2 OPEN

@skopz356 thank you very much for this issue.

To support your issue: https://usefulangle.com/post/17/html5-canvas-drawing-1px-crisp-straight-lines

To fix, we should check the borderWidth if odd or not and then change the annotation element size calculation as described in the document.
All annotation element sizes are calculated in the resolveElementProperties(chart, options) method of the annotation elements (in src/types).
This will affect also the test cases which should be changed.
Let me know if more info are needed to submit a PR. Otherwise I'll have a look asap.

from chartjs-plugin-annotation.

@skopz356 maybe it can help, you could try to set borderWidth: 0.5. It doesn't solve completely but improve.

from chartjs-plugin-annotation.