Possible bug with Mask?

Solar2D General Questions/Discussion
#1

Hi Corona Community,

I believe (but am not 100% sure) I have stumbled upon a bug relating to graphics.newMask( )

In my app, I have a background, and a separate image of clouds and a mask (a black circle on a white background) to make part of the clouds transparent, simulating a fog of war effect.

The bug is that, even though the mask is a circle and nothing more, parts of the image that are not supposed to be transparent are in fact transparent.

Speaking in more detail, portions of the image being masked along a “+” shaped path, are transparent (when they shouldn’t be).

Does anybody know whey this is happening? And more importantly, how to I prevent this?

Please find the attached files to get a better idea of what I am experiencing.

Thanks in advance! :slight_smile:

KC

#2

Your mask doesn’t follow the second rule of masks:

https://docs.coronalabs.com/daily/api/library/graphics/newMask.html#image-mask-requirements

The mask image must be bordered by at least 3 pixels of black space on all four sides. You may need to increase the overall size of your mask image to include this border.

#3

You want to use the technique used in the X-ray example that comes with the simulator.

#4

Your mask doesn’t follow the second rule of masks:

https://docs.coronalabs.com/daily/api/library/graphics/newMask.html#image-mask-requirements

The mask image must be bordered by at least 3 pixels of black space on all four sides. You may need to increase the overall size of your mask image to include this border.

#5

You want to use the technique used in the X-ray example that comes with the simulator.