Incorporate canvas position in mouse position calculation

[patrickocoffeyo]

Hey there! Sweet component you've got here, thanks for sharing :)

I'm working on a WebVR editorial experience in which I'm using this package to allow editors to drag/drop components around, and noticed that the mouse position was wrong for embedded WebVR scenes, so I modified the mechanism that calculates the mouses X/Y coordinates such that it incorporates the canvas's position (closely in line with what's in the cursor component in AFrame.

[jesstelford]

Thank you for this improvement! (Better late than never 😅)

[patrickocoffeyo]

Nice! Thanks for the review 😀