Solved Canvas issue
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After reading some docs, I am sure you are not telling something.
You want to draw on something that is white, correct?
So your canvas must be a child of something that is white.For instance:
Rectangle { color: white; Canvas { ... } }Is that the case here?
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@peteritv Yes, you are correct. In my case I set Canvas as a child of a white Window, but Context2D shows me, suddenly, that the canvas is the child of the black Window. Though it is displayed as white.
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OK, I just run your example, and it seems to work.
I have a white background on which I can draw.
When I draw I see the traces of my mouse with a big "point" size.
Draw color is blue.Everything seems to work.
Now, since I don't have your "Neuro" file, THAT may be your problem...
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We have a synchronisation issue here to :)
So when you run your program, you are drawing on a black thing?
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Where/How do you use Context2D?
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Ahhhh! I understand now! (I think)
You think that what ever background you choose, it will be part of your canvas?
That is NOT the case!The canvas just is a container for some points being drawn!
For instance, you can take the canvas, and put it on something else like a red Rectangle.
It will still have the same points, but now on a red background.In other words, the canvas does NOT hold any information at all about the background. It just knows about some pixels.
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So in your case, you need to fill your Canvas with white pixels itself.
So with ur ctx functions, draw a white rectangle first, which will be the base of your canvas for drawing on.
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So, instead of making your parent white:
Within your canvas, draw a white rectangle on start,
and then start drawing on that -
But that explaines why you see "black" instead of "white" on your Context2D
I am assuming you are just interested in the points, and not the background, for further processing.
So forget about the canvas background, ok? -
@peteritv Huge thanks, I finnally got what's going on! A visible background of working application is just a result of visual compositing the Canvas with it's parent and these two does not share any properties between each other. Thanks a lot again, I think it is very important to know such nuances.