Simple-Draw | A canvas you can draw on with different colors | Canvas library

When I draw a line slowly, I believe it detects it as multiple lines instead of one, so it darkens the line too much.

I’m following this tutorial https://www.raywenderlich.com/5895-uikit-drawing-tutorial-how-to-make-a-simple-drawing-app

I am following this tutorial, at the first when app launches everything is alright imagView is set where I set it. But the problem is when I start drawing on imageView the size of imageView resizes to ambiguous coordinates and it enlarges and occupy to much space result in ambiguous view, even I have set the auto layout. May be I am missing something, here is the code :

I'm trying to set an eraser tool for a drawing app. I've been following this tutorial for the basics, but the drawings happen in a white background so the deletion part is not covered (they draw in white color to delete) I've been implementing a method to delete my drawings, and it works pretty well. I draw a circle, set the color and the blend mode to clear and set the path where I want to draw that circle. Then I get an image returned by the method UIGraphicsGetImageFromCurrentImageContext() that updates my current image, with the new drawing over it. The drawn circle it's doing it's job and it deletes where it has been drawn. But the problem is the image begins to get deleted from the right to the left, covering all it's height, and this is certainly not set anywhere in my code. I don't know if it's a bug. I've tried everything and I can't get a new image from context without this new deletion line in the right. And the more I draw, the more the new line grows.

As you can see in the gif, it looks like I'm drawing in gray over a white background, but the white color is an image that has been filled with white color, and it's background color it's gray, so I'm deleting. The code:

In a UIView (blue background) I initialize and add two white columns as subviews:

I am using a tutorial to create the beginnings of a drawing app. The drawing occurs on one image view, and after a stroke is completed, it merges with an image view below and clears the top image.

Currently, my app can draw black figures on a white background. However, I would like for it to eventually draw figures on a transparent background so that any backgrounds/images/UIViews behind the main drawing views can be seen behind the figures. Would that be possible using the drawing method I've used?