Thanks a lot, your adjustments work well, I just need to change some parameters.
However, I found out that it only works if you put everything at the start position of the layout (0,0). This is really problematic as I was trying to put this image revealing section within a larger layout. And it does not work with mouse whatsoever.
I guess I have to make this section its own layout until a fix is found. Oh well.
Yeah, when you paste a sprite over the canvas, it should be exact the position you want to be covered.
You can use mouse for normal action like hover.
But the action like drawing should use touch then it will work well on mobile too.
How do you know that I am Vietnamese? :D
I saw your account name and the examination paper in your project, a traditional exam paper of Vietnamese pupils :))
Then I figured out that you are Vietnamese.
And I'm Vietnamese too :D