Added ability to draw a point as an inverted triangle.

[cholt0425]

Added ability to draw a point as an inverted triangle as it is useful
for showing progress along a bar, line, or scale.

[etimberg]

Code looks good. Thanks for updating the documentation. I think it would be worthwhile to add a test for this to https://github.com/chartjs/Chart.js/blob/master/test/specs/element.point.tests.js

[simonbrunel]

At this point, it would be much better to expose a new option (maybe pointRotation) instead of duplicating the drawing code for every use case because we could also have triangleRot (45°), triangleRotInv (-45°), triangleLeft (90°), triangleRight (-90°), etc. Then, we could deprecate crossRot (eq. cross + 45°) and RectRot (eq. rect + 45°), and it would also benefit to rectRounded, line and star without duplicating the drawing logic.

[cholt0425]

I'll add some tests. Question, I'm a newbie to using GitHub. Is there a way to add the tests and update this pull request or do you just submit an entirely new one? I just want to be sure that I make the change properly.

[cholt0425]

@simonbrunel I completely agree that would be a great feature. However, that is a huge breaking change for backwards compatibility. Perhaps in a major release chartjs can support both methods for a time: "Legacy Names" and "Name and Rotation"

[simonbrunel]

To update that PR, simply push new commits to your "master" branch.

There is no breaking change, we still use pattern names and add support for rotation (which will be handled by a new option). We deprecate *Rot patterns (basically, remove them for the docs). There should be only one additional canvas rotation and since the default for this new option will be 0, old code still work as expected.

[cholt0425]

@simonbrunel Thanks a bunch! It appears that worked nicely! I wanted to make sure I didn't disrupt things if I did it incorrectly. I submitted the unit test. The code climate checks wants me to refactor the beginning portion of the calculation but I'm thinking I should just not do that as it would probably add more complication for not much benefit. Do you agree?

[simonbrunel]

What I mean is that I would not add this extra string (triangleInv) since it duplicates code and calls for even more patterns, but instead introduce a new option to control the pattern rotation. Thus I would not merge that PR as is.

(though I agree to ignore CodeClimate report :) )

[benmccann]

@cholt0425 do you plan to update this PR in the way that Simon suggested? I'm wondering if we should leave this open or close it...

[benmccann]

@cholt0425 I would really love to see this feature and would love to help review any PR ad get it merged. I'm going to close this PR since it's been inactive for awhile, but please consider reopening or submitting a new PR to support the pointRotation option!